/* execute_cmd.c -- Execute a COMMAND structure. */
/* Copyright (C) 1987-2025 Free Software Foundation, Inc.
This file is part of GNU Bash, the Bourne Again SHell.
Bash is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Bash is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Bash. If not, see .
*/
#include "config.h"
#if !defined (__GNUC__) && !defined (HAVE_ALLOCA_H) && defined (_AIX)
#pragma alloca
#endif /* _AIX && RISC6000 && !__GNUC__ */
#include
#include "chartypes.h"
#include "bashtypes.h"
#if !defined (_MINIX) && defined (HAVE_SYS_FILE_H)
# include
#endif
#include "filecntl.h"
#include "posixstat.h"
#include
#if defined (HAVE_SYS_PARAM_H)
# include
#endif
#if defined (HAVE_UNISTD_H)
# include
#endif
#include "posixtime.h"
#if defined (HAVE_SYS_RESOURCE_H) && !defined (RLIMTYPE)
# include
#endif
#if defined (HAVE_SYS_TIMES_H) && defined (HAVE_TIMES)
# include
#endif
#include
#if !defined (errno)
extern int errno;
#endif
#define NEED_FPURGE_DECL
#define NEED_SH_SETLINEBUF_DECL
#define NEED_CLOCK_FUNCS_DECL
#define NEED_TIMEVAL_FUNCS_DECL
#include "bashansi.h"
#include "bashintl.h"
#include "memalloc.h"
#include "shell.h"
#include /* use <...> so we pick it up from the build directory */
#include "parser.h"
#include "flags.h"
#include "builtins.h"
#include "hashlib.h"
#include "jobs.h"
#include "execute_cmd.h"
#include "findcmd.h"
#include "redir.h"
#include "trap.h"
#include "pathexp.h"
#include "hashcmd.h"
#if defined (COND_COMMAND)
# include "test.h"
#endif
#include "builtins/common.h"
#include "builtins/builtext.h" /* list of builtins */
#include "builtins/getopt.h"
#include
#include
#include "input.h"
#if defined (ALIAS)
# include "alias.h"
#endif
#if defined (HISTORY)
# include "bashhist.h"
#endif
#if defined (HAVE_MBSTR_H) && defined (HAVE_MBSCHR)
# include /* mbschr */
#endif
extern int command_string_index;
extern char *the_printed_command;
extern time_t shell_start_time;
#if defined (HAVE_GETTIMEOFDAY)
extern struct timeval shellstart;
#endif
#if 0
extern char *glob_argv_flags;
#endif
extern int close (int);
/* Static functions defined and used in this file. */
static void close_pipes (int, int);
static void do_piping (int, int);
static int shell_control_structure (enum command_type);
static void cleanup_redirects (REDIRECT *);
#if defined (JOB_CONTROL)
static void uw_restore_signal_mask (void *);
#endif
static int builtin_status (int);
static int execute_for_command (FOR_COM *);
#if defined (SELECT_COMMAND)
static int displen (const char *);
static int print_index_and_element (int, int, WORD_LIST *);
static void indent (int, int);
static void print_select_list (WORD_LIST *, int, int, int);
static char *select_query (WORD_LIST *, int, char *, int);
static int execute_select_command (SELECT_COM *);
#endif
#if defined (DPAREN_ARITHMETIC)
static int execute_arith_command (ARITH_COM *);
#endif
#if defined (COND_COMMAND)
static int execute_cond_node (COND_COM *);
static int execute_cond_command (COND_COM *);
#endif
#if defined (COMMAND_TIMING)
static int mkfmt (char *, int, int, time_t, long);
static void print_formatted_time (FILE *, char *,
time_t, long, time_t, long,
time_t, long, int);
static int time_command (COMMAND *, int, int, int, struct fd_bitmap *);
#endif
#if defined (ARITH_FOR_COMMAND)
static intmax_t eval_arith_for_expr (WORD_LIST *, int *);
static int execute_arith_for_command (ARITH_FOR_COM *);
#endif
static int execute_case_command (CASE_COM *);
static int execute_while_command (WHILE_COM *);
static int execute_until_command (WHILE_COM *);
static int execute_while_or_until (WHILE_COM *, int);
static int execute_if_command (IF_COM *);
static int execute_null_command (REDIRECT *, int, int, int);
static void fix_assignment_words (WORD_LIST *);
static void fix_arrayref_words (WORD_LIST *);
static int execute_simple_command (SIMPLE_COM *, int, int, int, struct fd_bitmap *);
static int execute_builtin (sh_builtin_func_t *, WORD_LIST *, int, int);
static int execute_function (SHELL_VAR *, WORD_LIST *, int, struct fd_bitmap *, int, int);
static int execute_builtin_or_function (WORD_LIST *, sh_builtin_func_t *,
SHELL_VAR *,
REDIRECT *, struct fd_bitmap *, int);
static void execute_subshell_builtin_or_function (WORD_LIST *, REDIRECT *,
sh_builtin_func_t *,
SHELL_VAR *,
int, int, int,
struct fd_bitmap *,
int);
static int execute_disk_command (WORD_LIST *, REDIRECT *, char *,
int, int, int, struct fd_bitmap *, int);
static char *getinterp (char *, int, int *);
static void initialize_subshell (void);
static int execute_in_subshell (COMMAND *, int, int, int, struct fd_bitmap *);
#if defined (COPROCESS_SUPPORT)
static void coproc_setstatus (struct coproc *, WAIT);
static int execute_coproc (COMMAND *, int, int, struct fd_bitmap *);
#endif
static int execute_pipeline (COMMAND *, int, int, int, struct fd_bitmap *);
static int execute_connection (COMMAND *, int, int, int, struct fd_bitmap *);
static int execute_intern_function (WORD_DESC *, FUNCTION_DEF *);
/* Set to 1 if fd 0 was the subject of redirection to a subshell. Global
so that reader_loop can set it to zero before executing a command. */
int stdin_redir;
/* The name of the command that is currently being executed.
`test' needs this, for example. */
char *this_command_name;
/* The printed representation of the currently-executing command (same as
the_printed_command), except when a trap is being executed. Useful for
a debugger to know where exactly the program is currently executing. */
char *the_printed_command_except_trap;
/* Used to compute the correct line number. */
COMMAND *currently_executing_command;
/* For catching RETURN in a function. */
int return_catch_flag;
int return_catch_value;
procenv_t return_catch;
/* The value returned by the last synchronous command. */
volatile int last_command_exit_value;
/* Whether or not the last command (corresponding to last_command_exit_value)
was terminated by a signal, and, if so, which one. */
int last_command_exit_signal;
/* Are we currently ignoring the -e option for the duration of a builtin's
execution? */
int builtin_ignoring_errexit = 0;
/* The list of redirections to perform which will undo the redirections
that I made in the shell. */
REDIRECT *redirection_undo_list = (REDIRECT *)NULL;
/* The list of redirections to perform which will undo the internal
redirections performed by the `exec' builtin. These are redirections
that must be undone even when exec discards redirection_undo_list. */
REDIRECT *exec_redirection_undo_list = (REDIRECT *)NULL;
/* When greater than zero, value is the `level' of builtins we are
currently executing (e.g. `eval echo a' would have it set to 2). */
int executing_builtin = 0;
/* Non-zero if we are executing a command list (a;b;c, etc.) or a loop and we
should break out of it on a SIGINT. */
int interrupt_execution = 0;
/* Non-zero if we should defer closing process substitution FDs. */
int retain_fifos = 0;
/* Non-zero if failing commands in a command substitution should not exit the
shell even if -e is set. Used to pass the CMD_IGNORE_RETURN flag down to
commands run in command substitutions by parse_and_execute. */
int comsub_ignore_return = 0;
/* Non-zero if we have just forked and are currently running in a subshell
environment. */
int subshell_environment;
/* Count of nested subshells, like SHLVL. Available via $BASH_SUBSHELL */
int subshell_level = 0;
/* Currently-executing shell function. */
SHELL_VAR *this_shell_function;
/* Translated message printed when a command is not found. We declare it here
and initialize it in locale.c to work around a macOS bug that forces a
crash if bash calls setlocale(3) but does not call gettext(3) before
forking, then calls gettext() after forking. */
char *notfound_str = 0;
/* If non-zero, matches in case and [[ ... ]] are case-insensitive */
int match_ignore_case = 0;
int executing_command_builtin = 0;
struct stat SB; /* used for debugging */
static int special_builtin_failed;
/* The line number that the currently executing function starts on. */
static int function_line_number;
/* XXX - set to 1 if we're running the DEBUG trap and we want to show the line
number containing the function name. Used by executing_line_number to
report the correct line number. Kind of a hack. */
static int showing_function_line;
static int connection_count;
/* $LINENO ($BASH_LINENO) for use by an ERR trap. Global so parse_and_execute
can save and restore it. */
int line_number_for_err_trap;
/* A convenience macro to avoid resetting line_number_for_err_trap while
running the ERR trap. */
#define SET_LINE_NUMBER(v) \
do { \
line_number = v; \
if (signal_in_progress (ERROR_TRAP) == 0 && running_trap != (ERROR_TRAP + 1)) \
line_number_for_err_trap = line_number; \
} while (0)
/* This can't be in executing_line_number() because that's used for LINENO
and we want LINENO to reflect the line number of commands run during
the ERR trap. Right now this is only used to push to BASH_LINENO. */
#define GET_LINE_NUMBER() \
(signal_in_progress (ERROR_TRAP) && running_trap == ERROR_TRAP+1) \
? line_number_for_err_trap \
: executing_line_number ()
/* We adjust the line number when executing shell functions in an interactive
shell. */
#define ADJUST_LINE_NUMBER() \
do { \
if (variable_context && interactive_shell && sourcelevel == 0) \
{ \
/* line numbers in a function start at 1 */ \
line_number -= function_line_number - 1; \
if (line_number <= 0) \
line_number = 1; \
} \
} while (0)
/* A sort of function nesting level counter */
int funcnest = 0;
int funcnest_max = 0;
int evalnest = 0;
int evalnest_max = EVALNEST_MAX;
int sourcenest = 0;
int sourcenest_max = SOURCENEST_MAX;
volatile int from_return_trap = 0;
int lastpipe_opt = 0;
struct fd_bitmap *current_fds_to_close = (struct fd_bitmap *)NULL;
#define FD_BITMAP_DEFAULT_SIZE 32
/* Functions to allocate and deallocate the structures used to pass
information from the shell to its children about file descriptors
to close. */
struct fd_bitmap *
new_fd_bitmap (int size)
{
struct fd_bitmap *ret;
ret = (struct fd_bitmap *)xmalloc (sizeof (struct fd_bitmap));
ret->size = size;
if (size)
{
ret->bitmap = (char *)xmalloc (size);
memset (ret->bitmap, '\0', size);
}
else
ret->bitmap = (char *)NULL;
return (ret);
}
void
dispose_fd_bitmap (struct fd_bitmap *fdbp)
{
FREE (fdbp->bitmap);
free (fdbp);
}
void
uw_dispose_fd_bitmap (void *fdbp)
{
dispose_fd_bitmap (fdbp);
}
void
close_fd_bitmap (struct fd_bitmap *fdbp)
{
int i;
if (fdbp)
{
for (i = 0; i < fdbp->size; i++)
if (fdbp->bitmap[i])
{
close (i);
fdbp->bitmap[i] = 0;
}
}
}
static void
uw_close_fd_bitmap (void *fdbp)
{
close_fd_bitmap (fdbp);
}
void
uw_close (void *fd)
{
close ((intptr_t) fd); /* XXX */
}
static void
uw_restore_lineno (void *line)
{
line_number = (intptr_t) line;
}
/* Return the line number of the currently executing command. */
int
executing_line_number (void)
{
if (executing && showing_function_line == 0 &&
(variable_context == 0 || interactive_shell == 0) &&
currently_executing_command)
{
#if defined (COND_COMMAND)
if (currently_executing_command->type == cm_cond)
return currently_executing_command->value.Cond->line;
#endif
#if defined (DPAREN_ARITHMETIC)
if (currently_executing_command->type == cm_arith)
return currently_executing_command->value.Arith->line;
#endif
#if defined (ARITH_FOR_COMMAND)
if (currently_executing_command->type == cm_arith_for)
return currently_executing_command->value.ArithFor->line;
#endif
return line_number;
}
else
return line_number;
}
/* Execute the command passed in COMMAND. COMMAND is exactly what
read_command () places into GLOBAL_COMMAND. See "command.h" for the
details of the command structure.
EXECUTION_SUCCESS or EXECUTION_FAILURE are the only possible
return values. Executing a command with nothing in it returns
EXECUTION_SUCCESS. */
int
execute_command (COMMAND *command)
{
struct fd_bitmap *bitmap;
int result;
current_fds_to_close = (struct fd_bitmap *)NULL;
bitmap = new_fd_bitmap (FD_BITMAP_DEFAULT_SIZE);
begin_unwind_frame ("execute-command");
add_unwind_protect (uw_dispose_fd_bitmap, (char *)bitmap);
/* Just do the command, but not asynchronously. */
result = execute_command_internal (command, 0, NO_PIPE, NO_PIPE, bitmap);
dispose_fd_bitmap (bitmap);
discard_unwind_frame ("execute-command");
#if defined (PROCESS_SUBSTITUTION)
/* don't unlink fifos if we're in a shell function; wait until the function
returns. */
if (variable_context == 0 && retain_fifos == 0)
unlink_fifo_list ();
#endif /* PROCESS_SUBSTITUTION */
QUIT;
return (result);
}
/* Return 1 if TYPE is a shell control structure type. */
static int
shell_control_structure (enum command_type type)
{
switch (type)
{
#if defined (ARITH_FOR_COMMAND)
case cm_arith_for:
#endif
#if defined (SELECT_COMMAND)
case cm_select:
#endif
#if defined (DPAREN_ARITHMETIC)
case cm_arith:
#endif
#if defined (COND_COMMAND)
case cm_cond:
#endif
case cm_case:
case cm_while:
case cm_until:
case cm_if:
case cm_for:
case cm_group:
case cm_function_def:
return (1);
default:
return (0);
}
}
/* A function to use to unwind_protect the redirection undo list
for loops. */
static void
cleanup_redirects (REDIRECT *list)
{
do_redirections (list, RX_ACTIVE);
dispose_redirects (list);
}
static void
uw_cleanup_redirects (void *list)
{
cleanup_redirects (list);
}
static void
uw_dispose_redirects (void *list)
{
dispose_redirects (list);
}
void
undo_partial_redirects (void)
{
if (redirection_undo_list)
{
cleanup_redirects (redirection_undo_list);
redirection_undo_list = (REDIRECT *)NULL;
}
}
#if 0
/* Function to unwind_protect the redirections for functions and builtins. */
static void
cleanup_func_redirects (REDIRECT *list)
{
do_redirections (list, RX_ACTIVE);
}
#endif
void
dispose_exec_redirects (void)
{
if (exec_redirection_undo_list)
{
dispose_redirects (exec_redirection_undo_list);
exec_redirection_undo_list = (REDIRECT *)NULL;
}
}
void
dispose_partial_redirects (void)
{
if (redirection_undo_list)
{
dispose_redirects (redirection_undo_list);
redirection_undo_list = (REDIRECT *)NULL;
}
}
#if defined (JOB_CONTROL)
/* A function to restore the signal mask to its proper value when the shell
is interrupted or errors occur while creating a pipeline. */
static void
uw_restore_signal_mask (void *set)
{
sigprocmask (SIG_SETMASK, set, NULL);
}
#endif /* JOB_CONTROL */
#ifdef DEBUG
/* A debugging function that can be called from gdb, for instance. */
void
open_files (void)
{
int i;
int f, fd_table_size;
fd_table_size = getdtablesize ();
fprintf (stderr, "pid %ld open files:", (long)getpid ());
for (i = 3; i < fd_table_size; i++)
{
if ((f = fcntl (i, F_GETFD, 0)) != -1)
fprintf (stderr, " %d (%s)", i, f ? "close" : "open");
}
fprintf (stderr, "\n");
}
#endif
void
async_redirect_stdin (void)
{
int fd;
fd = open ("/dev/null", O_RDONLY);
if (fd > 0)
{
dup2 (fd, 0);
close (fd);
}
else if (fd < 0)
internal_error ("%s: %s", _("cannot redirect standard input from /dev/null"), strerror (errno));
}
#define DESCRIBE_PID(pid) do { if (interactive) describe_pid (pid); } while (0)
/* Execute the command passed in COMMAND, perhaps doing it asynchronously.
COMMAND is exactly what read_command () places into GLOBAL_COMMAND.
ASYNCHRONOUS, if non-zero, says to do this command in the background.
PIPE_IN and PIPE_OUT are file descriptors saying where input comes
from and where it goes. They can have the value of NO_PIPE, which means
I/O is stdin/stdout.
FDS_TO_CLOSE is a list of file descriptors to close once the child has
been forked. This list often contains the unusable sides of pipes, etc.
EXECUTION_SUCCESS or EXECUTION_FAILURE are the only possible
return values. Executing a command with nothing in it returns
EXECUTION_SUCCESS. */
int
execute_command_internal (COMMAND *command, int asynchronous, int pipe_in, int pipe_out, struct fd_bitmap *fds_to_close)
{
int exec_result, user_subshell, invert, ignore_return, was_error_trap, fork_flags;
REDIRECT *my_undo_list, *exec_undo_list;
char *tcmd;
volatile int save_line_number;
#if defined (PROCESS_SUBSTITUTION)
volatile int ofifo, nfifo, osize, saved_fifo;
void *ofifo_list; /* void * volatile ofifo_list; */
#endif
if (breaking || continuing)
return (last_command_exit_value);
if (read_but_dont_execute)
return (last_command_exit_value);
if (command == 0)
return (EXECUTION_SUCCESS);
QUIT;
run_pending_traps ();
#if 0
if (running_trap == 0)
#endif
currently_executing_command = command;
invert = (command->flags & CMD_INVERT_RETURN) != 0;
/* If we're inverting the return value and `set -e' has been executed,
we don't want a failing command to inadvertently cause the shell
to exit. */
if (exit_immediately_on_error && invert) /* XXX */
command->flags |= CMD_IGNORE_RETURN; /* XXX */
exec_result = EXECUTION_SUCCESS;
/* If a command was being explicitly run in a subshell, or if it is
a shell control-structure, and it has a pipe, then we do the command
in a subshell. */
if (command->type == cm_subshell && (command->flags & CMD_NO_FORK))
return (execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close));
#if defined (COPROCESS_SUPPORT)
if (command->type == cm_coproc)
return (last_command_exit_value = execute_coproc (command, pipe_in, pipe_out, fds_to_close));
#endif
user_subshell = command->type == cm_subshell || ((command->flags & CMD_WANT_SUBSHELL) != 0);
#if defined (TIME_BEFORE_SUBSHELL)
if ((command->flags & CMD_TIME_PIPELINE) && user_subshell && asynchronous == 0)
{
command->flags |= CMD_FORCE_SUBSHELL;
exec_result = time_command (command, asynchronous, pipe_in, pipe_out, fds_to_close);
currently_executing_command = (COMMAND *)NULL;
return (exec_result);
}
#endif
if (command->type == cm_subshell ||
(command->flags & (CMD_WANT_SUBSHELL|CMD_FORCE_SUBSHELL)) ||
(shell_control_structure (command->type) &&
(pipe_out != NO_PIPE || pipe_in != NO_PIPE || asynchronous)))
{
pid_t paren_pid;
int s;
char *p;
/* Fork a subshell, turn off the subshell bit, turn off job
control and call execute_command () on the command again. */
save_line_number = line_number;
if (command->type == cm_subshell)
SET_LINE_NUMBER (command->value.Subshell->line); /* XXX - save value? */
/* Otherwise we defer setting line_number */
tcmd = make_command_string (command);
fork_flags = asynchronous ? FORK_ASYNC : 0;
paren_pid = make_child (p = savestring (tcmd), fork_flags);
if (user_subshell && signal_is_trapped (ERROR_TRAP) &&
signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
{
FREE (the_printed_command_except_trap);
the_printed_command_except_trap = savestring (the_printed_command);
}
if (paren_pid == 0)
{
#if defined (JOB_CONTROL)
FREE (p); /* child doesn't use pointer */
#endif
/* We want to run the exit trap for forced {} subshells, and we
want to note this before execute_in_subshell modifies the
COMMAND struct. Need to keep in mind that execute_in_subshell
runs the exit trap for () subshells itself. */
/* This handles { command; } & */
s = user_subshell == 0 && command->type == cm_group && pipe_in == NO_PIPE && pipe_out == NO_PIPE && asynchronous;
/* run exit trap for : | { ...; } and { ...; } | : */
/* run exit trap for : | ( ...; ) and ( ...; ) | : */
s += user_subshell == 0 && command->type == cm_group && (pipe_in != NO_PIPE || pipe_out != NO_PIPE) && asynchronous == 0;
last_command_exit_value = execute_in_subshell (command, asynchronous, pipe_in, pipe_out, fds_to_close);
if (s)
subshell_exit (last_command_exit_value);
else
sh_exit (last_command_exit_value);
/* NOTREACHED */
}
else
{
close_pipes (pipe_in, pipe_out);
#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
if (variable_context == 0) /* wait until shell function completes */
unlink_fifo_list ();
#endif
/* Restore any saved state here before possible early return. */
line_number = save_line_number;
/* If we are part of a pipeline, and not the end of the pipeline,
then we should simply return and let the last command in the
pipe be waited for. If we are not in a pipeline, or are the
last command in the pipeline, then we wait for the subshell
and return its exit status as usual. */
if (pipe_out != NO_PIPE)
return (EXECUTION_SUCCESS);
stop_pipeline (asynchronous, (COMMAND *)NULL);
if (asynchronous == 0)
{
was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
invert = (command->flags & CMD_INVERT_RETURN) != 0;
ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
exec_result = wait_for (paren_pid, 0);
/* If we have to, invert the return value. */
if (invert)
exec_result = ((exec_result == EXECUTION_SUCCESS)
? EXECUTION_FAILURE
: EXECUTION_SUCCESS);
last_command_exit_value = exec_result;
if (user_subshell && was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
{
save_line_number = line_number;
line_number = line_number_for_err_trap;
run_error_trap ();
line_number = save_line_number;
}
if (user_subshell && ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS)
{
/* Update BASH_COMMAND before running any traps,
including the exit trap, since we are going to exit
the shell. */
if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
{
FREE (the_printed_command_except_trap);
the_printed_command_except_trap = savestring (the_printed_command);
}
run_pending_traps ();
jump_to_top_level (ERREXIT);
}
return (last_command_exit_value);
}
else
{
DESCRIBE_PID (paren_pid);
run_pending_traps ();
/* Posix 2013 2.9.3.1: "the exit status of an asynchronous list
shall be zero." */
last_command_exit_value = 0;
return (EXECUTION_SUCCESS);
}
}
}
#if defined (COMMAND_TIMING)
if (command->flags & CMD_TIME_PIPELINE)
{
if (asynchronous)
{
command->flags |= CMD_FORCE_SUBSHELL;
exec_result = execute_command_internal (command, 1, pipe_in, pipe_out, fds_to_close);
}
else
{
exec_result = time_command (command, asynchronous, pipe_in, pipe_out, fds_to_close);
#if 0
if (running_trap == 0)
#endif
currently_executing_command = (COMMAND *)NULL;
}
return (exec_result);
}
#endif /* COMMAND_TIMING */
if (shell_control_structure (command->type) && command->redirects)
stdin_redir = stdin_redirects (command->redirects);
#if defined (PROCESS_SUBSTITUTION)
# if !defined (HAVE_DEV_FD)
delete_procsubs (); /* closes fds or unlinks fifos */
# endif
/* XXX - also if sourcelevel != 0? */
if (variable_context != 0 || retain_fifos)
{
ofifo = num_fifos ();
ofifo_list = copy_fifo_list ((int *)&osize);
begin_unwind_frame ("internal_fifos");
if (ofifo_list)
add_unwind_protect (xfree, ofifo_list);
saved_fifo = 1;
}
else
saved_fifo = 0;
#endif
/* Handle WHILE FOR CASE etc. with redirections. (Also '&' input
redirection.) */
was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
if (do_redirections (command->redirects, RX_ACTIVE|RX_UNDOABLE) != 0)
{
undo_partial_redirects ();
dispose_exec_redirects ();
#if defined (PROCESS_SUBSTITUTION)
if (saved_fifo)
{
free (ofifo_list);
discard_unwind_frame ("internal_fifos");
}
#endif
/* Handle redirection error as command failure if errexit set. */
last_command_exit_value = EXECUTION_FAILURE;
if (ignore_return == 0 && invert == 0 && pipe_in == NO_PIPE && pipe_out == NO_PIPE)
{
if (was_error_trap)
{
save_line_number = line_number;
line_number = line_number_for_err_trap;
run_error_trap ();
line_number = save_line_number;
}
if (exit_immediately_on_error)
{
run_pending_traps ();
jump_to_top_level (ERREXIT);
}
}
return (last_command_exit_value);
}
my_undo_list = redirection_undo_list;
redirection_undo_list = (REDIRECT *)NULL;
exec_undo_list = exec_redirection_undo_list;
exec_redirection_undo_list = (REDIRECT *)NULL;
if (my_undo_list || exec_undo_list)
begin_unwind_frame ("loop_redirections");
if (my_undo_list)
add_unwind_protect (uw_cleanup_redirects, my_undo_list);
if (exec_undo_list)
add_unwind_protect (uw_dispose_redirects, exec_undo_list);
QUIT;
switch (command->type)
{
case cm_simple:
{
save_line_number = line_number;
/* We can't rely on variables retaining their values across a
call to execute_simple_command if a longjmp occurs as the
result of a `return' builtin. This is true for sure with gcc. */
#if defined (RECYCLES_PIDS)
last_made_pid = NO_PID;
#endif
was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
if ((ignore_return || invert) && command->value.Simple)
command->value.Simple->flags |= CMD_IGNORE_RETURN;
if (command->flags & CMD_STDIN_REDIR)
command->value.Simple->flags |= CMD_STDIN_REDIR;
begin_unwind_frame ("simple_lineno");
add_unwind_protect (uw_restore_lineno, (void *) (intptr_t) save_line_number);
/* Limit the scope of this attempted optimization for now: async
commands for which TRY_OPTIMIZING is set (see call to optimize_shell_function
for async functions in execute_subshell_builtin_or_function below)
in interactive and script shells. */
if ((command->flags & CMD_TRY_OPTIMIZING) &&
(subshell_environment & SUBSHELL_ASYNC) && startup_state < 2 &&
should_optimize_fork (command, 0))
{
command->flags |= CMD_NO_FORK;
command->value.Simple->flags |= CMD_NO_FORK;
}
SET_LINE_NUMBER (command->value.Simple->line);
exec_result =
execute_simple_command (command->value.Simple, pipe_in, pipe_out,
asynchronous, fds_to_close);
line_number = save_line_number;
discard_unwind_frame ("simple_lineno");
/* The temporary environment should be used for only the simple
command immediately following its definition. */
dispose_used_env_vars ();
#if (defined (ultrix) && defined (mips)) || defined (C_ALLOCA)
/* Reclaim memory allocated with alloca () on machines which
may be using the alloca emulation code. */
(void) alloca (0);
#endif /* (ultrix && mips) || C_ALLOCA */
/* If we forked to do the command, then we must wait_for ()
the child. */
/* XXX - this is something to watch out for if there are problems
when the shell is compiled without job control. Don't worry about
whether or not last_made_pid == last_pid; already_making_children
tells us whether or not there are unwaited-for children to wait
for and reap. */
if (already_making_children && pipe_out == NO_PIPE)
{
stop_pipeline (asynchronous, (COMMAND *)NULL);
if (asynchronous)
{
DESCRIBE_PID (last_made_pid);
exec_result = EXECUTION_SUCCESS;
invert = 0; /* async commands always succeed */
}
else
#if !defined (JOB_CONTROL)
/* Do not wait for asynchronous processes started from
startup files. */
if (last_made_pid != NO_PID && last_made_pid != last_asynchronous_pid)
#else
if (last_made_pid != NO_PID)
#endif
/* When executing a shell function that executes other
commands, this causes the last simple command in
the function to be waited for twice. This also causes
subshells forked to execute builtin commands (e.g., in
pipelines) to be waited for twice. */
exec_result = wait_for (last_made_pid, 0);
}
}
/* 2009/02/13 -- pipeline failure is processed elsewhere. This handles
only the failure of a simple command. We don't want to run the error
trap if the command run by the `command' builtin fails; we want to
defer that until the command builtin itself returns failure. */
/* 2020/07/14 -- this changes with how the command builtin is handled */
if (was_error_trap && ignore_return == 0 && invert == 0 &&
pipe_in == NO_PIPE && pipe_out == NO_PIPE &&
(command->value.Simple->flags & CMD_COMMAND_BUILTIN) == 0 &&
exec_result != EXECUTION_SUCCESS)
{
last_command_exit_value = exec_result;
line_number = line_number_for_err_trap;
run_error_trap ();
line_number = save_line_number;
}
if (ignore_return == 0 && invert == 0 &&
((posixly_correct && interactive == 0 && special_builtin_failed) ||
(exit_immediately_on_error && pipe_in == NO_PIPE && pipe_out == NO_PIPE && exec_result != EXECUTION_SUCCESS)))
{
last_command_exit_value = exec_result;
run_pending_traps ();
/* Undo redirections before running exit trap on the way out of
set -e. Report by Mark Farrell 5/19/2014 */
if (exit_immediately_on_error && signal_is_trapped (0) &&
unwind_protect_tag_on_stack ("saved-redirects"))
run_unwind_frame ("saved-redirects");
jump_to_top_level (ERREXIT);
}
break;
case cm_for:
if (ignore_return || invert)
command->value.For->flags |= CMD_IGNORE_RETURN;
exec_result = execute_for_command (command->value.For);
break;
#if defined (ARITH_FOR_COMMAND)
case cm_arith_for:
if (ignore_return || invert)
command->value.ArithFor->flags |= CMD_IGNORE_RETURN;
exec_result = execute_arith_for_command (command->value.ArithFor);
break;
#endif
#if defined (SELECT_COMMAND)
case cm_select:
if (ignore_return || invert)
command->value.Select->flags |= CMD_IGNORE_RETURN;
exec_result = execute_select_command (command->value.Select);
break;
#endif
case cm_case:
if (ignore_return || invert)
command->value.Case->flags |= CMD_IGNORE_RETURN;
exec_result = execute_case_command (command->value.Case);
break;
case cm_while:
if (ignore_return || invert)
command->value.While->flags |= CMD_IGNORE_RETURN;
exec_result = execute_while_command (command->value.While);
break;
case cm_until:
if (ignore_return || invert)
command->value.While->flags |= CMD_IGNORE_RETURN;
exec_result = execute_until_command (command->value.While);
break;
case cm_if:
if (ignore_return || invert)
command->value.If->flags |= CMD_IGNORE_RETURN;
exec_result = execute_if_command (command->value.If);
break;
case cm_group:
/* This code can be executed from either of two paths: an explicit
'{}' command, or via a function call. If we are executed via a
function call, we have already taken care of the function being
executed in the background (down there in execute_simple_command ()),
and this command should *not* be marked as asynchronous. If we
are executing a regular '{}' group command, and asynchronous == 1,
we must want to execute the whole command in the background, so we
need a subshell, and we want the stuff executed in that subshell
(this group command) to be executed in the foreground of that
subshell (i.e. there will not be *another* subshell forked).
What we do is to force a subshell if asynchronous, and then call
execute_command_internal again with asynchronous still set to 1,
but with the original group command, so the printed command will
look right.
The code above that handles forking off subshells will note that
both subshell and async are on, and turn off async in the child
after forking the subshell (but leave async set in the parent, so
the normal call to describe_pid is made). This turning off
async is *crucial*; if it is not done, this will fall into an
infinite loop of executions through this spot in subshell after
subshell until the process limit is exhausted. */
if (asynchronous)
{
command->flags |= CMD_FORCE_SUBSHELL;
exec_result =
execute_command_internal (command, 1, pipe_in, pipe_out,
fds_to_close);
}
else
{
/* If we're already ignoring the return value of this group command,
or if the return value is being inverted, make sure to ignore
set -e for the duration of the command, even if the group
command enables it. */
if ((ignore_return || invert) && command->value.Group->command)
command->value.Group->command->flags |= CMD_IGNORE_RETURN;
exec_result =
execute_command_internal (command->value.Group->command,
asynchronous, pipe_in, pipe_out,
fds_to_close);
}
break;
case cm_connection:
exec_result = execute_connection (command, asynchronous,
pipe_in, pipe_out, fds_to_close);
if (asynchronous)
invert = 0; /* XXX */
break;
#if defined (DPAREN_ARITHMETIC)
case cm_arith:
#endif
#if defined (COND_COMMAND)
case cm_cond:
#endif
case cm_function_def:
was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
#if defined (DPAREN_ARITHMETIC)
if (ignore_return && command->type == cm_arith)
command->value.Arith->flags |= CMD_IGNORE_RETURN;
#endif
#if defined (COND_COMMAND)
if (ignore_return && command->type == cm_cond)
command->value.Cond->flags |= CMD_IGNORE_RETURN;
#endif
line_number_for_err_trap = save_line_number = line_number; /* XXX */
begin_unwind_frame ("misc_compound");
add_unwind_protect (uw_restore_lineno, (void *) (intptr_t) save_line_number);
#if defined (DPAREN_ARITHMETIC)
if (command->type == cm_arith)
exec_result = execute_arith_command (command->value.Arith);
else
#endif
#if defined (COND_COMMAND)
if (command->type == cm_cond)
exec_result = execute_cond_command (command->value.Cond);
else
#endif
if (command->type == cm_function_def)
exec_result = execute_intern_function (command->value.Function_def->name,
command->value.Function_def);
line_number = save_line_number;
discard_unwind_frame ("misc_compound");
if (was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
{
last_command_exit_value = exec_result;
save_line_number = line_number;
line_number = line_number_for_err_trap;
run_error_trap ();
line_number = save_line_number;
}
if (ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS)
{
last_command_exit_value = exec_result;
run_pending_traps ();
jump_to_top_level (ERREXIT);
}
break;
default:
command_error ("execute_command", CMDERR_BADTYPE, command->type, 0);
}
if (my_undo_list)
cleanup_redirects (my_undo_list);
if (exec_undo_list)
dispose_redirects (exec_undo_list);
if (my_undo_list || exec_undo_list)
discard_unwind_frame ("loop_redirections");
#if defined (PROCESS_SUBSTITUTION)
if (saved_fifo)
{
nfifo = num_fifos ();
if (nfifo > ofifo)
close_new_fifos (ofifo_list, osize);
free (ofifo_list);
discard_unwind_frame ("internal_fifos");
}
#endif
/* Invert the return value if we have to */
if (invert)
exec_result = (exec_result == EXECUTION_SUCCESS)
? EXECUTION_FAILURE
: EXECUTION_SUCCESS;
#if defined (DPAREN_ARITHMETIC) || defined (COND_COMMAND)
/* This is where we set PIPESTATUS from the exit status of the appropriate
compound commands (the ones that look enough like simple commands to
cause confusion). We might be able to optimize by not doing this if
subshell_environment != 0. */
switch (command->type)
{
# if defined (DPAREN_ARITHMETIC)
case cm_arith:
# endif
# if defined (COND_COMMAND)
case cm_cond:
# endif
set_pipestatus_from_exit (exec_result);
break;
default:
break;
}
#endif
last_command_exit_value = exec_result;
run_pending_traps ();
currently_executing_command = (COMMAND *)NULL;
return (last_command_exit_value);
}
#if defined (COMMAND_TIMING)
#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
extern struct timeval *difftimeval (struct timeval *, struct timeval *, struct timeval *);
extern struct timeval *addtimeval (struct timeval *, struct timeval *, struct timeval *);
extern int timeval_to_cpu (struct timeval *, struct timeval *, struct timeval *);
#endif
#define POSIX_TIMEFORMAT "real %2R\nuser %2U\nsys %2S"
#define BASH_TIMEFORMAT "\nreal\t%3lR\nuser\t%3lU\nsys\t%3lS"
static const int precs[] = { 0, 100000, 10000, 1000, 100, 10, 1 };
static const int maxvals[] = { 1, 10, 100, 1000, 10000, 100000, 10000000 };
/* Expand one `%'-prefixed escape sequence from a time format string. */
/* SEC_FRACTION is in usecs. We normalize and round that based on the
precision. */
int
mkfmt (char *buf, int prec, int lng, time_t sec, long sec_fraction)
{
time_t min;
char abuf[INT_STRLEN_BOUND(time_t) + 1];
int ind, aind;
ind = 0;
abuf[sizeof(abuf) - 1] = '\0';
/* If LNG is non-zero, we want to decompose SEC into minutes and seconds. */
if (lng)
{
min = sec / 60;
sec %= 60;
aind = sizeof(abuf) - 2;
do
abuf[aind--] = (min % 10) + '0';
while (min /= 10);
aind++;
while (abuf[aind])
buf[ind++] = abuf[aind++];
buf[ind++] = 'm';
}
/* Now add the seconds. */
aind = sizeof (abuf) - 2;
do
abuf[aind--] = (sec % 10) + '0';
while (sec /= 10);
aind++;
while (abuf[aind])
buf[ind++] = abuf[aind++];
/* We want to add a decimal point and PREC places after it if PREC is
nonzero. PREC is not greater than 6. SEC_FRACTION is between 0
and 999999 (microseconds). */
if (prec != 0)
{
/* We round here because we changed timeval_to_secs to return
microseconds and normalized clock_t_to_secs's fractional return
value to microseconds, deferring the work to be done to now.
sec_fraction is in microseconds. Take the value, cut off what we
don't want, round up if necessary, then convert back to
microseconds. */
if (prec != 6)
{
int frac, rest, maxval;
maxval = maxvals[6 - prec];
frac = sec_fraction / maxval;
rest = sec_fraction % maxval;
if (rest >= maxval/2)
frac++;
sec_fraction = frac * (1000000 / maxvals[prec]);
}
buf[ind++] = locale_decpoint ();
for (aind = 1; aind <= prec; aind++)
{
buf[ind++] = (sec_fraction / precs[aind]) + '0';
sec_fraction %= precs[aind];
}
}
if (lng)
buf[ind++] = 's';
buf[ind] = '\0';
return (ind);
}
/* Interpret the format string FORMAT, interpolating the following escape
sequences:
%[prec][l][RUS]
where the optional `prec' is a precision, meaning the number of
characters after the decimal point, the optional `l' means to format
using minutes and seconds (MMmNN[.FF]s), like the `times' builtin',
and the last character is one of
R number of seconds of `real' time
U number of seconds of `user' time
S number of seconds of `system' time
An occurrence of `%%' in the format string is translated to a `%'. The
result is printed to FP, a pointer to a FILE. The other variables are
the seconds and thousandths of a second of real, user, and system time,
resectively. */
static void
print_formatted_time (FILE *fp, char *format,
time_t rs, long rsf, time_t us, long usf, time_t ss, long ssf,
int cpu)
{
int prec, lng, len;
char *str, *s, ts[INT_STRLEN_BOUND (time_t) + sizeof ("mSS.FFFF")];
time_t sum;
long sum_frac;
int sindex, ssize;
len = strlen (format);
ssize = (len + 64) - (len % 64);
str = (char *)xmalloc (ssize);
sindex = 0;
for (s = format; *s; s++)
{
if (*s != '%' || s[1] == '\0')
{
RESIZE_MALLOCED_BUFFER (str, sindex, 1, ssize, 64);
str[sindex++] = *s;
}
else if (s[1] == '%')
{
s++;
RESIZE_MALLOCED_BUFFER (str, sindex, 1, ssize, 64);
str[sindex++] = *s;
}
else if (s[1] == 'P')
{
s++;
#if 0
/* clamp CPU usage at 100% */
if (cpu > 10000)
cpu = 10000;
#endif
sum = cpu / 100;
sum_frac = (cpu % 100) * 10;
len = mkfmt (ts, 2, 0, sum, sum_frac);
RESIZE_MALLOCED_BUFFER (str, sindex, len, ssize, 64);
strcpy (str + sindex, ts);
sindex += len;
}
else
{
prec = 3; /* default is three places past the decimal point. */
lng = 0; /* default is to not use minutes or append `s' */
s++;
if (DIGIT (*s)) /* `precision' */
{
prec = *s++ - '0';
if (prec > 6) prec = 6;
}
if (*s == 'l') /* `length extender' */
{
lng = 1;
s++;
}
if (*s == 'R' || *s == 'E')
len = mkfmt (ts, prec, lng, rs, rsf);
else if (*s == 'U')
len = mkfmt (ts, prec, lng, us, usf);
else if (*s == 'S')
len = mkfmt (ts, prec, lng, ss, ssf);
else
{
internal_error (_("TIMEFORMAT: `%c': invalid format character"), *s);
free (str);
return;
}
RESIZE_MALLOCED_BUFFER (str, sindex, len, ssize, 64);
strcpy (str + sindex, ts);
sindex += len;
}
}
str[sindex] = '\0';
fprintf (fp, "%s\n", str);
fflush (fp);
free (str);
}
static int
time_command (COMMAND *command, int asynchronous, int pipe_in, int pipe_out, struct fd_bitmap *fds_to_close)
{
int rv, posix_time, nullcmd, code;
time_t rs, us, ss; /* seconds */
long rsf, usf, ssf; /* microseconds */
int cpu;
char *time_format;
volatile procenv_t save_top_level;
volatile int old_subshell, old_flags;
#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
struct timeval real, user, sys;
struct timeval before, after;
# if defined (HAVE_STRUCT_TIMEZONE)
struct timezone dtz; /* posix doesn't define this */
# endif
struct rusage selfb, selfa, kidsb, kidsa; /* a = after, b = before */
#else
# if defined (HAVE_TIMES)
clock_t tbefore, tafter, real, user, sys;
struct tms before, after;
# endif
#endif
#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
# if defined (HAVE_STRUCT_TIMEZONE)
gettimeofday (&before, &dtz);
# else
gettimeofday (&before, NULL);
# endif /* !HAVE_STRUCT_TIMEZONE */
getrusage (RUSAGE_SELF, &selfb);
getrusage (RUSAGE_CHILDREN, &kidsb);
#else
# if defined (HAVE_TIMES)
tbefore = times (&before);
# endif
#endif
old_subshell = subshell_environment;
posix_time = command && (command->flags & CMD_TIME_POSIX);
nullcmd = (command == 0) || (command->type == cm_simple && command->value.Simple->words == 0 && command->value.Simple->redirects == 0);
if (posixly_correct && nullcmd)
{
#if defined (HAVE_GETRUSAGE)
selfb.ru_utime.tv_sec = kidsb.ru_utime.tv_sec = selfb.ru_stime.tv_sec = kidsb.ru_stime.tv_sec = 0;
selfb.ru_utime.tv_usec = kidsb.ru_utime.tv_usec = selfb.ru_stime.tv_usec = kidsb.ru_stime.tv_usec = 0;
before = shellstart;
#else
before.tms_utime = before.tms_stime = before.tms_cutime = before.tms_cstime = 0;
tbefore = shell_start_time;
#endif
}
rv = EXECUTION_SUCCESS; /* suppress uninitialized use warnings */
old_flags = command->flags;
COPY_PROCENV (top_level, save_top_level);
command->flags &= ~(CMD_TIME_PIPELINE|CMD_TIME_POSIX);
code = setjmp_nosigs (top_level);
if (code == NOT_JUMPED)
rv = execute_command_internal (command, asynchronous, pipe_in, pipe_out, fds_to_close);
COPY_PROCENV (save_top_level, top_level);
if (code == NOT_JUMPED)
command->flags = old_flags;
/* If we're jumping in a different subshell environment than we started,
don't bother printing timing stats, just keep longjmping back to the
original top level. */
if (code != NOT_JUMPED && subshell_environment && subshell_environment != old_subshell)
sh_longjmp (top_level, code);
rs = us = ss = 0;
rsf = usf = ssf = 0;
cpu = 0;
#if defined (HAVE_GETRUSAGE) && defined (HAVE_GETTIMEOFDAY)
# if defined (HAVE_STRUCT_TIMEZONE)
gettimeofday (&after, &dtz);
# else
gettimeofday (&after, NULL);
# endif /* !HAVE_STRUCT_TIMEZONE */
getrusage (RUSAGE_SELF, &selfa);
getrusage (RUSAGE_CHILDREN, &kidsa);
difftimeval (&real, &before, &after);
timeval_to_secs (&real, &rs, &rsf, 1000000);
addtimeval (&user, difftimeval(&after, &selfb.ru_utime, &selfa.ru_utime),
difftimeval(&before, &kidsb.ru_utime, &kidsa.ru_utime));
timeval_to_secs (&user, &us, &usf, 1000000);
addtimeval (&sys, difftimeval(&after, &selfb.ru_stime, &selfa.ru_stime),
difftimeval(&before, &kidsb.ru_stime, &kidsa.ru_stime));
timeval_to_secs (&sys, &ss, &ssf, 1000000);
cpu = timeval_to_cpu (&real, &user, &sys);
#else
# if defined (HAVE_TIMES)
tafter = times (&after);
real = tafter - tbefore;
clock_t_to_secs (real, &rs, &rsf);
/* clock_t_to_secs returns RSF in milliseconds; multipy by 1000 to get microseconds. */
rsf *= 1000;
user = (after.tms_utime - before.tms_utime) + (after.tms_cutime - before.tms_cutime);
clock_t_to_secs (user, &us, &usf);
usf *= 1000;
sys = (after.tms_stime - before.tms_stime) + (after.tms_cstime - before.tms_cstime);
clock_t_to_secs (sys, &ss, &ssf);
ssf *= 1000;
cpu = (real == 0) ? 0 : ((user + sys) * 10000) / real;
# else
rs = us = ss = 0;
rsf = usf = ssf = cpu = 0;
# endif
#endif
if (posix_time)
time_format = POSIX_TIMEFORMAT;
else if ((time_format = get_string_value ("TIMEFORMAT")) == 0)
{
if (posixly_correct && nullcmd)
time_format = "user\t%2lU\nsys\t%2lS";
else
time_format = BASH_TIMEFORMAT;
}
if (time_format && *time_format)
print_formatted_time (stderr, time_format, rs, rsf, us, usf, ss, ssf, cpu);
if (code)
sh_longjmp (top_level, code);
return rv;
}
#endif /* COMMAND_TIMING */
/* Execute a command that's supposed to be in a subshell. This must be
called after make_child and we must be running in the child process.
The caller will return or exit() immediately with the value this returns. */
static int
execute_in_subshell (COMMAND *command, int asynchronous, int pipe_in, int pipe_out, struct fd_bitmap *fds_to_close)
{
volatile int user_subshell, user_coproc, invert;
int return_code, function_value, should_redir_stdin, ois, result;
volatile COMMAND *tcom;
USE_VAR(user_subshell);
USE_VAR(user_coproc);
USE_VAR(invert);
USE_VAR(tcom);
USE_VAR(asynchronous);
subshell_level++;
should_redir_stdin = (asynchronous && (command->flags & CMD_STDIN_REDIR) &&
pipe_in == NO_PIPE &&
stdin_redirects (command->redirects) == 0);
invert = (command->flags & CMD_INVERT_RETURN) != 0;
user_subshell = command->type == cm_subshell || ((command->flags & CMD_WANT_SUBSHELL) != 0);
user_coproc = command->type == cm_coproc;
command->flags &= ~(CMD_FORCE_SUBSHELL | CMD_WANT_SUBSHELL | CMD_INVERT_RETURN);
/* If a command is asynchronous in a subshell (like ( foo ) & or
the special case of an asynchronous GROUP command where the
subshell bit is turned on down in case cm_group: above),
turn off `asynchronous', so that two subshells aren't spawned.
XXX - asynchronous used to be set to 0 in this block, but that
means that setup_async_signals was never run. Now it's set to
0 after subshell_environment is set appropriately and setup_async_signals
is run.
This seems semantically correct to me. For example,
( foo ) & seems to say ``do the command `foo' in a subshell
environment, but don't wait for that subshell to finish'',
and "{ foo ; bar ; } &" seems to me to be like functions or
builtins in the background, which executed in a subshell
environment. I just don't see the need to fork two subshells. */
/* Don't fork again, we are already in a subshell. A `doubly
async' shell is not interactive, however. */
if (asynchronous)
{
#if defined (JOB_CONTROL)
/* If a construct like ( exec xxx yyy ) & is given while job
control is active, we want to prevent exec from putting the
subshell back into the original process group, carefully
undoing all the work we just did in make_child. */
original_pgrp = -1;
#endif /* JOB_CONTROL */
ois = interactive_shell;
interactive_shell = 0;
/* This test is to prevent alias expansion by interactive shells that
run `(command) &' but to allow scripts that have enabled alias
expansion with `shopt -s expand_alias' to continue to expand
aliases. */
if (ois != interactive_shell)
expand_aliases = expaliases_flag = 0;
}
/* Subshells are neither login nor interactive. */
login_shell = interactive = 0;
/* And we're no longer in a loop. See Posix interp 842 (we are not in the
"same execution environment"). */
if (shell_compatibility_level > 44)
loop_level = 0;
if (user_subshell)
{
subshell_environment = SUBSHELL_PAREN; /* XXX */
if (asynchronous)
subshell_environment |= SUBSHELL_ASYNC;
}
else
{
subshell_environment = 0; /* XXX */
if (asynchronous)
subshell_environment |= SUBSHELL_ASYNC;
if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
subshell_environment |= SUBSHELL_PIPE;
if (user_coproc)
subshell_environment |= SUBSHELL_COPROC;
}
QUIT;
CHECK_TERMSIG;
reset_terminating_signals (); /* in sig.c */
/* Cancel traps, in trap.c. */
/* Reset the signal handlers in the child, but don't free the
trap strings. Set a flag noting that we have to free the
trap strings if we run trap to change a signal disposition. */
clear_pending_traps ();
reset_signal_handlers ();
subshell_environment |= SUBSHELL_RESETTRAP;
/* Note that signal handlers have been reset, so we should no longer
reset the handler and resend trapped signals to ourselves. */
subshell_environment &= ~SUBSHELL_IGNTRAP;
/* We are in a subshell, so forget that we are running a trap handler or
that the signal handler has changed (we haven't changed it!) */
/* XXX - maybe do this for `real' signals and not ERR/DEBUG/RETURN/EXIT
traps? */
if (running_trap > 0)
{
run_trap_cleanup (running_trap - 1);
running_trap = 0; /* XXX - maybe leave this */
}
/* Make sure restore_original_signals doesn't undo the work done by
make_child to ensure that asynchronous children are immune to SIGINT
and SIGQUIT. Turn off asynchronous to make sure more subshells are
not spawned. */
if (asynchronous)
{
setup_async_signals ();
asynchronous = 0;
}
else
/* XXX - restore if old handler is SIG_IGN like we do in
execute_subshell_builtin_or_function? */
set_sigint_handler ();
#if defined (JOB_CONTROL)
set_sigchld_handler ();
#endif /* JOB_CONTROL */
/* Delete all traces that there were any jobs running. This is
only for subshells. */
without_job_control ();
if (fds_to_close)
close_fd_bitmap (fds_to_close);
do_piping (pipe_in, pipe_out);
#if defined (COPROCESS_SUPPORT)
coproc_closeall ();
#endif
#if defined (PROCESS_SUBSTITUTION)
# if defined (JOB_CONTROL)
procsub_clear ();
# endif
clear_fifo_list (); /* XXX- we haven't created any FIFOs */
#endif
/* If this is a user subshell, set a flag if stdin was redirected.
This is used later to decide whether to redirect fd 0 to
/dev/null for async commands in the subshell. This adds more
sh compatibility, but I'm not sure it's the right thing to do.
Note that an input pipe to a compound command suffices to inhibit
the implicit /dev/null redirection for asynchronous commands
executed as part of that compound command. */
if (user_subshell)
{
stdin_redir = stdin_redirects (command->redirects) || pipe_in != NO_PIPE;
#if 0
restore_default_signal (EXIT_TRAP); /* XXX - reset_signal_handlers above */
#endif
}
else if (shell_control_structure (command->type) && pipe_in != NO_PIPE)
stdin_redir = 1;
/* If this is an asynchronous command (command &), we want to
redirect the standard input from /dev/null in the absence of
any specific redirection involving stdin. */
if (should_redir_stdin && stdin_redir == 0)
async_redirect_stdin ();
/* In any case, we are not reading our command input from stdin. */
default_buffered_input = -1;
/* We can't optimize away forks if one of the commands executed by the
subshell sets an exit trap, so we set CMD_NO_FORK for simple commands
and set CMD_TRY_OPTIMIZING for simple commands on the right side of an
and-or or `;' list to test for optimizing forks when they are executed. */
if (user_subshell && command->type == cm_subshell &&
(command->flags & (CMD_TIME_PIPELINE|CMD_INVERT_RETURN)) == 0)
optimize_subshell_command (command->value.Subshell->command);
/* Do redirections, then dispose of them before recursive call. */
if (command->redirects)
{
if (do_redirections (command->redirects, RX_ACTIVE) != 0)
exit (invert ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
dispose_redirects (command->redirects);
command->redirects = (REDIRECT *)NULL;
#if 1
#if defined (PROCESS_SUBSTITUTION) && defined (JOB_CONTROL)
if (user_subshell && command->type == cm_subshell)
procsub_clear ();
#endif
#endif
}
if (command->type == cm_subshell)
tcom = command->value.Subshell->command;
else if (user_coproc)
tcom = command->value.Coproc->command;
else
tcom = command;
if (command->flags & CMD_TIME_PIPELINE)
tcom->flags |= CMD_TIME_PIPELINE;
if (command->flags & CMD_TIME_POSIX)
tcom->flags |= CMD_TIME_POSIX;
/* Make sure the subshell inherits any CMD_IGNORE_RETURN flag. */
if ((command->flags & CMD_IGNORE_RETURN) && tcom != command)
tcom->flags |= CMD_IGNORE_RETURN;
/* If the subshell's return value is being inverted, ignore set -e even
if the subshell enables it. */
if (invert)
tcom->flags |= CMD_IGNORE_RETURN;
/* If this is a simple command, tell execute_disk_command that it
might be able to get away without forking and simply exec.
This means things like ( sleep 10 ) will only cause one fork.
If we're timing the command or inverting its return value, however,
we cannot do this optimization. */
if ((user_subshell || user_coproc) && (tcom->type == cm_simple || tcom->type == cm_subshell) &&
((tcom->flags & CMD_TIME_PIPELINE) == 0) &&
((tcom->flags & CMD_INVERT_RETURN) == 0))
{
tcom->flags |= CMD_NO_FORK;
if (tcom->type == cm_simple)
tcom->value.Simple->flags |= CMD_NO_FORK;
}
invert = (tcom->flags & CMD_INVERT_RETURN) != 0;
tcom->flags &= ~CMD_INVERT_RETURN;
result = setjmp_nosigs (top_level);
/* If we're inside a function while executing this subshell, we
need to handle a possible `return'. */
function_value = 0;
if (return_catch_flag)
function_value = setjmp_nosigs (return_catch);
/* If we're going to exit the shell, we don't want to invert the return
status. */
if (result == EXITPROG || result == EXITBLTIN)
invert = 0, return_code = last_command_exit_value;
else if (result)
return_code = (last_command_exit_value == EXECUTION_SUCCESS) ? EXECUTION_FAILURE : last_command_exit_value;
else if (function_value)
return_code = return_catch_value;
else
return_code = execute_command_internal ((COMMAND *)tcom, asynchronous, NO_PIPE, NO_PIPE, fds_to_close);
/* If we are asked to, invert the return value. */
if (invert)
return_code = (return_code == EXECUTION_SUCCESS) ? EXECUTION_FAILURE
: EXECUTION_SUCCESS;
/* Check for terminating signals before we return to our caller, which we
expect to exit immediately anyway. */
CHECK_TERMSIG;
/* If we were explicitly placed in a subshell with (), we need
to do the `shell cleanup' things, such as running traps[0]. */
if (user_subshell && signal_is_trapped (0))
{
last_command_exit_value = return_code;
return_code = run_exit_trap ();
}
#if 0
subshell_level--; /* don't bother, caller will just exit */
#endif
return (return_code);
/* NOTREACHED */
}
#if defined (COPROCESS_SUPPORT)
#define COPROC_MAX 16
typedef struct cpelement
{
struct cpelement *next;
struct coproc *coproc;
}
cpelement_t;
typedef struct cplist
{
struct cpelement *head;
struct cpelement *tail;
int ncoproc;
int lock;
}
cplist_t;
static struct cpelement *cpe_alloc (struct coproc *);
static void cpe_dispose (struct cpelement *);
static struct cpelement *cpl_add (struct coproc *);
static struct cpelement *cpl_delete (pid_t);
static void cpl_reap (void);
static void cpl_flush (void);
static void cpl_closeall (void);
static struct cpelement *cpl_search (pid_t);
static struct cpelement *cpl_searchbyname (const char *);
static void cpl_prune (void);
static void coproc_free (struct coproc *);
/* Will go away when there is fully-implemented support for multiple coprocs. */
Coproc sh_coproc = { 0, NO_PID, -1, -1, 0, 0, 0, 0, 0 };
cplist_t coproc_list = {0, 0, 0};
/* Functions to manage the list of coprocs */
static struct cpelement *
cpe_alloc (Coproc *cp)
{
struct cpelement *cpe;
cpe = (struct cpelement *)xmalloc (sizeof (struct cpelement));
cpe->coproc = cp;
cpe->next = (struct cpelement *)0;
return cpe;
}
static void
cpe_dispose (struct cpelement *cpe)
{
free (cpe);
}
static struct cpelement *
cpl_add (Coproc *cp)
{
struct cpelement *cpe;
cpe = cpe_alloc (cp);
if (coproc_list.head == 0)
{
coproc_list.head = coproc_list.tail = cpe;
coproc_list.ncoproc = 0; /* just to make sure */
}
else
{
coproc_list.tail->next = cpe;
coproc_list.tail = cpe;
}
coproc_list.ncoproc++;
return cpe;
}
static struct cpelement *
cpl_delete (pid_t pid)
{
struct cpelement *prev, *p;
for (prev = p = coproc_list.head; p; prev = p, p = p->next)
if (p->coproc->c_pid == pid)
{
prev->next = p->next; /* remove from list */
break;
}
if (p == 0)
return 0; /* not found */
INTERNAL_DEBUG (("cpl_delete: deleting %d", pid));
/* Housekeeping in the border cases. */
if (p == coproc_list.head)
coproc_list.head = coproc_list.head->next;
else if (p == coproc_list.tail)
coproc_list.tail = prev;
coproc_list.ncoproc--;
if (coproc_list.ncoproc == 0)
coproc_list.head = coproc_list.tail = 0;
else if (coproc_list.ncoproc == 1)
coproc_list.tail = coproc_list.head; /* just to make sure */
return (p);
}
static void
cpl_reap (void)
{
struct cpelement *p, *next, *nh, *nt;
/* Build a new list by removing dead coprocs and fix up the coproc_list
pointers when done. */
nh = nt = next = (struct cpelement *)0;
for (p = coproc_list.head; p; p = next)
{
next = p->next;
if (p->coproc->c_flags & COPROC_DEAD)
{
coproc_list.ncoproc--; /* keep running count, fix up pointers later */
#if 0
INTERNAL_DEBUG (("cpl_reap: deleting %d", p->coproc->c_pid));
#endif
coproc_dispose (p->coproc);
cpe_dispose (p);
}
else if (nh == 0)
nh = nt = p;
else
{
nt->next = p;
nt = nt->next;
}
}
if (coproc_list.ncoproc == 0)
coproc_list.head = coproc_list.tail = 0;
else
{
if (nt)
nt->next = 0;
coproc_list.head = nh;
coproc_list.tail = nt;
if (coproc_list.ncoproc == 1)
coproc_list.tail = coproc_list.head; /* just to make sure */
}
}
/* Clear out the list of saved statuses */
static void
cpl_flush (void)
{
struct cpelement *cpe, *p;
for (cpe = coproc_list.head; cpe; )
{
p = cpe;
cpe = cpe->next;
coproc_dispose (p->coproc);
cpe_dispose (p);
}
coproc_list.head = coproc_list.tail = 0;
coproc_list.ncoproc = 0;
}
static void
cpl_closeall (void)
{
struct cpelement *cpe;
for (cpe = coproc_list.head; cpe; cpe = cpe->next)
coproc_close (cpe->coproc);
}
static void
cpl_fdchk (int fd)
{
struct cpelement *cpe;
for (cpe = coproc_list.head; cpe; cpe = cpe->next)
coproc_checkfd (cpe->coproc, fd);
}
/* Search for PID in the list of coprocs; return the cpelement struct if
found. If not found, return NULL. */
static struct cpelement *
cpl_search (pid_t pid)
{
struct cpelement *cpe;
for (cpe = coproc_list.head ; cpe; cpe = cpe->next)
if (cpe->coproc->c_pid == pid)
return cpe;
return (struct cpelement *)NULL;
}
/* Search for the coproc named NAME in the list of coprocs; return the
cpelement struct if found. If not found, return NULL. */
static struct cpelement *
cpl_searchbyname (const char *name)
{
struct cpelement *cp;
for (cp = coproc_list.head ; cp; cp = cp->next)
if (STREQ (cp->coproc->c_name, name))
return cp;
return (struct cpelement *)NULL;
}
static pid_t
cpl_firstactive (void)
{
struct cpelement *cpe;
for (cpe = coproc_list.head ; cpe; cpe = cpe->next)
if ((cpe->coproc->c_flags & COPROC_DEAD) == 0)
return cpe->coproc->c_pid;
return (pid_t)NO_PID;
}
#if 0
static void
cpl_prune (void)
{
struct cpelement *cp;
while (coproc_list.head && coproc_list.ncoproc > COPROC_MAX)
{
cp = coproc_list.head;
coproc_list.head = coproc_list.head->next;
coproc_dispose (cp->coproc);
cpe_dispose (cp);
coproc_list.ncoproc--;
}
}
#endif
/* These currently use a single global "shell coproc" but are written in a
way to not preclude additional coprocs later (using the list management
package above). */
struct coproc *
getcoprocbypid (pid_t pid)
{
#if MULTIPLE_COPROCS
struct cpelement *p;
p = cpl_search (pid);
return (p ? p->coproc : 0);
#else
return (pid == sh_coproc.c_pid ? &sh_coproc : 0);
#endif
}
struct coproc *
getcoprocbyname (const char *name)
{
#if MULTIPLE_COPROCS
struct cpelement *p;
p = cpl_searchbyname (name);
return (p ? p->coproc : 0);
#else
return ((sh_coproc.c_name && STREQ (sh_coproc.c_name, name)) ? &sh_coproc : 0);
#endif
}
void
coproc_init (struct coproc *cp)
{
cp->c_name = 0;
cp->c_pid = NO_PID;
cp->c_rfd = cp->c_wfd = -1;
cp->c_rsave = cp->c_wsave = -1;
cp->c_flags = cp->c_status = cp->c_lock = 0;
}
struct coproc *
coproc_alloc (char *name, pid_t pid)
{
struct coproc *cp;
#if MULTIPLE_COPROCS
cp = (struct coproc *)xmalloc (sizeof (struct coproc));
#else
cp = &sh_coproc;
#endif
coproc_init (cp);
cp->c_lock = 2;
cp->c_pid = pid;
cp->c_name = savestring (name);
#if MULTIPLE_COPROCS
cpl_add (cp);
#endif
cp->c_lock = 0;
return (cp);
}
static void
coproc_free (struct coproc *cp)
{
free (cp);
}
void
coproc_dispose (struct coproc *cp)
{
sigset_t set, oset;
if (cp == 0)
return;
BLOCK_SIGNAL (SIGCHLD, set, oset);
cp->c_lock = 3;
coproc_unsetvars (cp);
FREE (cp->c_name);
coproc_close (cp);
#if MULTIPLE_COPROCS
coproc_free (cp);
#else
coproc_init (cp);
cp->c_lock = 0;
#endif
UNBLOCK_SIGNAL (oset);
}
/* Placeholder for now. Will require changes for multiple coprocs */
void
coproc_flush (void)
{
#if MULTIPLE_COPROCS
cpl_flush ();
#else
coproc_dispose (&sh_coproc);
#endif
}
void
coproc_close (struct coproc *cp)
{
if (cp->c_rfd >= 0)
{
close (cp->c_rfd);
cp->c_rfd = -1;
}
if (cp->c_wfd >= 0)
{
close (cp->c_wfd);
cp->c_wfd = -1;
}
cp->c_rsave = cp->c_wsave = -1;
}
void
coproc_closeall (void)
{
#if MULTIPLE_COPROCS
cpl_closeall ();
#else
coproc_close (&sh_coproc); /* XXX - will require changes for multiple coprocs */
#endif
}
void
coproc_reap (void)
{
#if MULTIPLE_COPROCS
cpl_reap ();
#else
struct coproc *cp;
cp = &sh_coproc; /* XXX - will require changes for multiple coprocs */
if (cp && (cp->c_flags & COPROC_DEAD))
{
INTERNAL_DEBUG (("coproc_reap: deleting %d", cp->c_pid));
coproc_dispose (cp);
}
#endif
}
void
coproc_rclose (struct coproc *cp, int fd)
{
if (cp->c_rfd >= 0 && cp->c_rfd == fd)
{
close (cp->c_rfd);
cp->c_rfd = -1;
}
}
void
coproc_wclose (struct coproc *cp, int fd)
{
if (cp->c_wfd >= 0 && cp->c_wfd == fd)
{
close (cp->c_wfd);
cp->c_wfd = -1;
}
}
void
coproc_checkfd (struct coproc *cp, int fd)
{
int update;
update = 0;
if (cp->c_rfd >= 0 && cp->c_rfd == fd)
update = cp->c_rfd = -1;
if (cp->c_wfd >= 0 && cp->c_wfd == fd)
update = cp->c_wfd = -1;
if (update)
coproc_setvars (cp);
}
void
coproc_fdchk (int fd)
{
#if MULTIPLE_COPROCS
cpl_fdchk (fd);
#else
coproc_checkfd (&sh_coproc, fd);
#endif
}
void
coproc_fdclose (struct coproc *cp, int fd)
{
coproc_rclose (cp, fd);
coproc_wclose (cp, fd);
coproc_setvars (cp);
}
void
coproc_fdsave (struct coproc *cp)
{
cp->c_rsave = cp->c_rfd;
cp->c_wsave = cp->c_wfd;
}
void
coproc_fdrestore (struct coproc *cp)
{
cp->c_rfd = cp->c_rsave;
cp->c_wfd = cp->c_wsave;
}
/* Translate an exit status encoded in WAIT into a coproc state */
static inline int
coproc_getstate (WAIT status)
{
if (WIFEXITED (status) || WIFSIGNALED (status))
return COPROC_DEAD;
else if (WIFSTOPPED (status))
return (COPROC_STOPPED|COPROC_RUNNING);
else if (WIFCONTINUED (status))
return COPROC_RUNNING;
else
return COPROC_DEAD; /* defaults to terminated */
}
static void
coproc_setstatus (struct coproc *cp, WAIT status)
{
cp->c_lock = 4;
cp->c_status = process_exit_status (status);
cp->c_flags &= ~(COPROC_DEAD|COPROC_STOPPED|COPROC_FOREGROUND|COPROC_RUNNING);
cp->c_flags |= coproc_getstate (status);
/* Don't dispose the coproc or unset the COPROC_XXX variables because
this is executed in a signal handler context. Wait until coproc_reap
takes care of it. */
cp->c_lock = 0;
}
void
coproc_pidchk (pid_t pid, WAIT status)
{
struct coproc *cp;
#if MULTIPLE_COPROCS
struct cpelement *cpe;
/* We're not disposing the coproc because this is executed in a signal
handler context */
cpe = cpl_search (pid);
cp = cpe ? cpe->coproc : 0;
#else
cp = getcoprocbypid (pid);
#endif
if (cp)
coproc_setstatus (cp, status);
}
pid_t
coproc_active (void)
{
#if MULTIPLE_COPROCS
return (cpl_firstactive ());
#else
return ((sh_coproc.c_flags & COPROC_DEAD) ? NO_PID : sh_coproc.c_pid);
#endif
}
void
coproc_setvars (struct coproc *cp)
{
SHELL_VAR *v;
char *namevar, *t;
size_t l;
WORD_DESC w;
#if defined (ARRAY_VARS)
arrayind_t ind;
#endif
if (cp->c_name == 0)
return;
/* We could do more here but right now we only check the name, warn if it's
not a valid identifier, and refuse to create variables with invalid names
if a coproc with such a name is supplied. */
w.word = cp->c_name;
w.flags = 0;
if (check_identifier (&w, 1) == 0)
return;
l = strlen (cp->c_name);
namevar = xmalloc (l + 16);
#if defined (ARRAY_VARS)
v = find_variable (cp->c_name);
/* This is the same code as in find_or_make_array_variable */
if (v == 0)
{
v = find_variable_nameref_for_create (cp->c_name, 1);
if (v == INVALID_NAMEREF_VALUE)
{
free (namevar);
return;
}
if (v && nameref_p (v))
{
free (cp->c_name);
cp->c_name = savestring (nameref_cell (v));
v = make_new_array_variable (cp->c_name);
}
}
if (v && ASSIGN_DISALLOWED (v, 0))
{
if (readonly_p (v))
err_readonly (cp->c_name);
free (namevar);
return;
}
if (v == 0)
v = make_new_array_variable (cp->c_name);
if (array_p (v) == 0)
v = convert_var_to_array (v);
t = itos (cp->c_rfd);
ind = 0;
v = bind_array_variable (cp->c_name, ind, t, 0);
free (t);
t = itos (cp->c_wfd);
ind = 1;
v = bind_array_variable (cp->c_name, ind, t, 0);
free (t);
#else
sprintf (namevar, "%s_READ", cp->c_name);
t = itos (cp->c_rfd);
bind_variable (namevar, t, 0);
free (t);
sprintf (namevar, "%s_WRITE", cp->c_name);
t = itos (cp->c_wfd);
bind_variable (namevar, t, 0);
free (t);
#endif
sprintf (namevar, "%s_PID", cp->c_name);
t = itos (cp->c_pid);
v = bind_variable (namevar, t, 0);
free (t);
free (namevar);
}
void
coproc_unsetvars (struct coproc *cp)
{
size_t l;
char *namevar;
if (cp->c_name == 0)
return;
l = strlen (cp->c_name);
namevar = xmalloc (l + 16);
sprintf (namevar, "%s_PID", cp->c_name);
unbind_variable_noref (namevar);
#if defined (ARRAY_VARS)
check_unbind_variable (cp->c_name);
#else
sprintf (namevar, "%s_READ", cp->c_name);
unbind_variable (namevar);
sprintf (namevar, "%s_WRITE", cp->c_name);
unbind_variable (namevar);
#endif
free (namevar);
}
static int
execute_coproc (COMMAND *command, int pipe_in, int pipe_out, struct fd_bitmap *fds_to_close)
{
int rpipe[2], wpipe[2], estat, invert;
pid_t coproc_pid;
Coproc *cp;
char *tcmd, *p, *name;
sigset_t set, oset;
#if !MULTIPLE_COPROCS
int oldrfd, oldwfd;
#endif
/* XXX -- can be removed after changes to handle multiple coprocs */
#if !MULTIPLE_COPROCS
oldrfd = oldwfd = -1;
if (sh_coproc.c_pid != NO_PID && (sh_coproc.c_rfd >= 0 || sh_coproc.c_wfd >= 0))
{
internal_warning (_("execute_coproc: coproc [%d:%s] still exists"), sh_coproc.c_pid, sh_coproc.c_name);
oldrfd = sh_coproc.c_rfd;
oldwfd = sh_coproc.c_wfd;
}
coproc_init (&sh_coproc);
#endif
invert = (command->flags & CMD_INVERT_RETURN) != 0;
/* expand name without splitting - could make this dependent on a shopt option */
name = expand_string_unsplit_to_string (command->value.Coproc->name, 0);
/* Optional check -- could be relaxed */
if (valid_identifier (name) == 0)
{
err_invalidid (name);
free (name);
return (invert ? EXECUTION_SUCCESS : EXECUTION_FAILURE);
}
else
{
free (command->value.Coproc->name);
command->value.Coproc->name = name;
}
command_string_index = 0;
tcmd = make_command_string (command);
sh_openpipe ((int *)&rpipe); /* 0 = parent read, 1 = child write */
sh_openpipe ((int *)&wpipe); /* 0 = child read, 1 = parent write */
BLOCK_SIGNAL (SIGCHLD, set, oset);
coproc_pid = make_child (p = savestring (tcmd), FORK_ASYNC);
if (coproc_pid == 0)
{
close (rpipe[0]);
close (wpipe[1]);
#if !MULTIPLE_COPROCS
/* Do this here instead of letting execute_in_subshell call
coproc_closeall since we've already overwritten sh_coproc */
if (oldrfd != -1)
close (oldrfd);
if (oldwfd != -1)
close (oldwfd);
#endif
#if defined (JOB_CONTROL)
FREE (p);
#endif
UNBLOCK_SIGNAL (oset);
estat = execute_in_subshell (command, 1, wpipe[0], rpipe[1], fds_to_close);
fflush (stdout);
fflush (stderr);
exit (estat);
}
close (rpipe[1]);
close (wpipe[0]);
cp = coproc_alloc (command->value.Coproc->name, coproc_pid);
cp->c_rfd = rpipe[0];
cp->c_wfd = wpipe[1];
cp->c_flags |= COPROC_RUNNING;
SET_CLOSE_ON_EXEC (cp->c_rfd);
SET_CLOSE_ON_EXEC (cp->c_wfd);
coproc_setvars (cp);
UNBLOCK_SIGNAL (oset);
#if 0
itrace ("execute_coproc (%s): [%d] %s", command->value.Coproc->name, coproc_pid, the_printed_command);
#endif
close_pipes (pipe_in, pipe_out);
#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
if (variable_context == 0)
unlink_fifo_list ();
#endif
stop_pipeline (1, (COMMAND *)NULL);
DESCRIBE_PID (coproc_pid);
run_pending_traps ();
return (invert ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
}
#endif
/* If S == -1, it's a special value saying to close stdin */
static void
restore_stdin (int s)
{
if (s == -1)
close (0);
else
{
dup2 (s, 0);
close (s);
}
}
static void
uw_restore_stdin (void *s)
{
restore_stdin ((intptr_t)s);
}
static void
uw_merge_temporary_env (void *ignore)
{
merge_temporary_env ();
}
/* Catch-all cleanup function for lastpipe code for unwind-protects */
void
uw_lastpipe_cleanup (void *s)
{
set_jobs_list_frozen ((intptr_t) s);
}
static int
execute_pipeline (COMMAND *command, int asynchronous, int pipe_in, int pipe_out, struct fd_bitmap *fds_to_close)
{
int prev, fildes[2], new_bitmap_size, dummyfd, ignore_return, invert, exec_result;
int lstdin, lastpipe_flag, lastpipe_jid, old_frozen, stdin_valid;
COMMAND *cmd;
struct fd_bitmap *fd_bitmap;
pid_t lastpid;
#if defined (JOB_CONTROL)
sigset_t set, oset;
BLOCK_CHILD (set, oset);
#endif /* JOB_CONTROL */
ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
invert = (command->flags & CMD_INVERT_RETURN) != 0;
stdin_valid = sh_validfd (0);
prev = pipe_in;
cmd = command;
while (cmd && cmd->type == cm_connection &&
cmd->value.Connection && cmd->value.Connection->connector == '|')
{
/* Make a pipeline between the two commands. */
if (pipe (fildes) < 0)
{
sys_error (_("pipe error"));
#if defined (JOB_CONTROL)
terminate_current_pipeline ();
kill_current_pipeline ();
UNBLOCK_CHILD (oset);
#endif /* JOB_CONTROL */
last_command_exit_value = EXECUTION_FAILURE;
/* The unwind-protects installed below will take care
of closing all of the open file descriptors. */
throw_to_top_level ();
return (EXECUTION_FAILURE); /* XXX */
}
/* Here is a problem: with the new file close-on-exec
code, the read end of the pipe (fildes[0]) stays open
in the first process, so that process will never get a
SIGPIPE. There is no way to signal the first process
that it should close fildes[0] after forking, so it
remains open. No SIGPIPE is ever sent because there
is still a file descriptor open for reading connected
to the pipe. We take care of that here. This passes
around a bitmap of file descriptors that must be
closed after making a child process in execute_simple_command. */
/* We need fd_bitmap to be at least as big as fildes[0].
If fildes[0] is less than fds_to_close->size, then
use fds_to_close->size. */
new_bitmap_size = (fildes[0] < fds_to_close->size)
? fds_to_close->size
: fildes[0] + 8;
fd_bitmap = new_fd_bitmap (new_bitmap_size);
/* Now copy the old information into the new bitmap. */
xbcopy ((char *)fds_to_close->bitmap, (char *)fd_bitmap->bitmap, fds_to_close->size);
/* And mark the pipe file descriptors to be closed. */
fd_bitmap->bitmap[fildes[0]] = 1;
/* In case there are pipe or out-of-processes errors, we
want all these file descriptors to be closed when
unwind-protects are run, and the storage used for the
bitmaps freed up. */
begin_unwind_frame ("pipe-file-descriptors");
add_unwind_protect (uw_dispose_fd_bitmap, fd_bitmap);
add_unwind_protect (uw_close_fd_bitmap, fd_bitmap);
if (prev >= 0)
add_unwind_protect (uw_close, (void *) (intptr_t) prev);
dummyfd = fildes[1];
add_unwind_protect (uw_close, (void *) (intptr_t) dummyfd);
#if defined (JOB_CONTROL)
add_unwind_protect (uw_restore_signal_mask, &oset);
#endif /* JOB_CONTROL */
if ((ignore_return || invert) && cmd->value.Connection->first)
cmd->value.Connection->first->flags |= CMD_IGNORE_RETURN;
execute_command_internal (cmd->value.Connection->first, asynchronous,
prev, fildes[1], fd_bitmap);
if (prev >= 0)
close (prev);
prev = fildes[0];
close (fildes[1]);
dispose_fd_bitmap (fd_bitmap);
discard_unwind_frame ("pipe-file-descriptors");
cmd = cmd->value.Connection->second;
}
lastpid = last_made_pid;
/* Now execute the rightmost command in the pipeline. */
if ((ignore_return || invert) && cmd)
cmd->flags |= CMD_IGNORE_RETURN;
lastpipe_flag = 0;
begin_unwind_frame ("lastpipe-exec");
lstdin = -2; /* -1 is special, meaning fd 0 is closed */
/* If the `lastpipe' option is set with shopt, and job control is not
enabled, execute the last element of non-async pipelines in the
current shell environment. */
/* prev can be 0 if fd 0 was closed when this function was executed. prev
will never be 0 at this point if fd 0 was valid when this function was
executed (though we check above). */
if (lastpipe_opt && job_control == 0 && asynchronous == 0 && pipe_out == NO_PIPE && prev >= 0)
{
/* -1 is a special value meaning to close stdin */
lstdin = (prev > 0 && stdin_valid) ? move_to_high_fd (0, 1, -1) : -1;
if (lstdin > 0 || lstdin == -1)
{
do_piping (prev, pipe_out);
prev = NO_PIPE;
add_unwind_protect (uw_restore_stdin, (void *) (intptr_t) lstdin);
lastpipe_flag = 1;
old_frozen = freeze_jobs_list (1);
lastpipe_jid = stop_pipeline (0, (COMMAND *)NULL); /* XXX */
add_unwind_protect (uw_lastpipe_cleanup, (void *) (intptr_t) old_frozen);
#if defined (JOB_CONTROL)
UNBLOCK_CHILD (oset); /* XXX */
#endif
}
if (cmd)
cmd->flags |= CMD_LASTPIPE;
}
if (prev >= 0)
add_unwind_protect (uw_close, (void *) (intptr_t) prev);
exec_result = execute_command_internal (cmd, asynchronous, prev, pipe_out, fds_to_close);
if (prev >= 0)
close (prev);
if (lstdin > 0 || lstdin == -1)
restore_stdin (lstdin);
#if defined (JOB_CONTROL)
UNBLOCK_CHILD (oset);
#endif
QUIT;
if (lastpipe_flag)
{
#if defined (JOB_CONTROL)
if (INVALID_JOB (lastpipe_jid) == 0)
{
append_process (savestring (the_printed_command_except_trap), dollar_dollar_pid, exec_result, lastpipe_jid);
lstdin = wait_for (lastpid, 0);
}
else
{
lstdin = wait_for_single_pid (lastpid, 0); /* checks bgpids list */
if (lstdin > 256) /* error sentinel */
lstdin = 127;
}
#else
lstdin = wait_for (lastpid, 0);
#endif
#if defined (JOB_CONTROL)
/* If wait_for removes the job from the jobs table, use result of last
command as pipeline's exit status as usual. The jobs list can get
frozen and unfrozen at inconvenient times if there are multiple pipelines
running simultaneously. */
if (INVALID_JOB (lastpipe_jid) == 0)
exec_result = job_exit_status (lastpipe_jid);
else if (pipefail_opt)
exec_result = exec_result | lstdin; /* XXX */
/* otherwise we use exec_result */
#endif
set_jobs_list_frozen (old_frozen);
}
discard_unwind_frame ("lastpipe-exec");
return (exec_result);
}
static int
execute_connection (COMMAND *command, int asynchronous, int pipe_in, int pipe_out, struct fd_bitmap *fds_to_close)
{
COMMAND *tc, *second;
int ignore_return, exec_result, was_error_trap, invert;
volatile int save_line_number;
ignore_return = (command->flags & CMD_IGNORE_RETURN) != 0;
invert = (command->flags & CMD_INVERT_RETURN) != 0;
switch (command->value.Connection->connector)
{
/* Do the first command asynchronously. */
case '&':
tc = command->value.Connection->first;
if (tc == 0)
return (EXECUTION_SUCCESS);
if (ignore_return)
tc->flags |= CMD_IGNORE_RETURN;
tc->flags |= CMD_AMPERSAND;
/* If this shell was compiled without job control support,
if we are currently in a subshell via `( xxx )', or if job
control is not active then the standard input for an
asynchronous command is forced to /dev/null. */
#if defined (JOB_CONTROL)
if ((subshell_environment || !job_control) && !stdin_redir)
#else
if (!stdin_redir)
#endif /* JOB_CONTROL */
tc->flags |= CMD_STDIN_REDIR;
exec_result = execute_command_internal (tc, 1, pipe_in, pipe_out, fds_to_close);
QUIT;
if (tc->flags & CMD_STDIN_REDIR)
tc->flags &= ~CMD_STDIN_REDIR;
second = command->value.Connection->second;
if (second)
{
if (ignore_return)
second->flags |= CMD_IGNORE_RETURN;
exec_result = execute_command_internal (second, asynchronous, pipe_in, pipe_out, fds_to_close);
}
break;
/* Just call execute command on both sides. */
case ';':
case '\n': /* special case, happens in command substitutions */
if (ignore_return || invert)
{
if (command->value.Connection->first)
command->value.Connection->first->flags |= CMD_IGNORE_RETURN;
if (command->value.Connection->second)
command->value.Connection->second->flags |= CMD_IGNORE_RETURN;
}
interrupt_execution++; retain_fifos++;
QUIT;
#if 1
execute_command (command->value.Connection->first);
#else
execute_command_internal (command->value.Connection->first,
asynchronous, pipe_in, pipe_out,
fds_to_close);
#endif
QUIT;
#if defined (JOB_CONTROL)
if (command->value.Connection->connector == ';' && job_control && interactive && posixly_correct == 0)
notify_and_cleanup (-1);
#endif
optimize_connection_fork (command); /* XXX */
exec_result = execute_command_internal (command->value.Connection->second,
asynchronous, pipe_in, pipe_out,
fds_to_close);
interrupt_execution--; retain_fifos--;
break;
case '|':
was_error_trap = signal_is_trapped (ERROR_TRAP) && signal_is_ignored (ERROR_TRAP) == 0;
SET_LINE_NUMBER (line_number); /* XXX - save value? */
exec_result = execute_pipeline (command, asynchronous, pipe_in, pipe_out, fds_to_close);
if (asynchronous)
{
exec_result = EXECUTION_SUCCESS;
invert = 0;
}
if (was_error_trap && ignore_return == 0 && invert == 0 && exec_result != EXECUTION_SUCCESS)
{
last_command_exit_value = exec_result;
save_line_number = line_number;
line_number = line_number_for_err_trap;
run_error_trap ();
line_number = save_line_number;
}
if (ignore_return == 0 && invert == 0 && exit_immediately_on_error && exec_result != EXECUTION_SUCCESS)
{
last_command_exit_value = exec_result;
run_pending_traps ();
jump_to_top_level (ERREXIT);
}
break;
case AND_AND:
case OR_OR:
if (asynchronous)
{
/* If we have something like `a && b &' or `a || b &', run the
&& or || stuff in a subshell. Force a subshell and just call
execute_command_internal again. Leave asynchronous on
so that we get a report from the parent shell about the
background job. */
command->flags |= CMD_FORCE_SUBSHELL;
exec_result = execute_command_internal (command, 1, pipe_in, pipe_out, fds_to_close);
break;
}
/* Execute the first command. If the result of that is successful
and the connector is AND_AND, or the result is not successful
and the connector is OR_OR, then execute the second command,
otherwise return. */
interrupt_execution++; retain_fifos++;
if (command->value.Connection->first)
command->value.Connection->first->flags |= CMD_IGNORE_RETURN;
#if 1
exec_result = execute_command (command->value.Connection->first);
#else
exec_result = execute_command_internal (command->value.Connection->first, 0, NO_PIPE, NO_PIPE, fds_to_close);
#endif
QUIT;
if (((command->value.Connection->connector == AND_AND) &&
(exec_result == EXECUTION_SUCCESS)) ||
((command->value.Connection->connector == OR_OR) &&
(exec_result != EXECUTION_SUCCESS)))
{
optimize_connection_fork (command);
second = command->value.Connection->second;
if (ignore_return && second)
second->flags |= CMD_IGNORE_RETURN;
exec_result = execute_command (second);
}
interrupt_execution--; retain_fifos--;
break;
default:
command_error ("execute_connection", CMDERR_BADCONN, command->value.Connection->connector, 0);
jump_to_top_level (DISCARD);
exec_result = EXECUTION_FAILURE;
}
return exec_result;
}
/* The test used to be only for interactive_shell, but we don't want to report
job status when the shell is not interactive or when job control isn't
enabled. */
#define REAP() \
do \
{ \
if (job_control == 0 || interactive_shell == 0) \
reap_dead_jobs (); \
} \
while (0)
/* Execute a FOR command. The syntax is: FOR word_desc IN word_list;
DO command; DONE */
static int
execute_for_command (FOR_COM *for_command)
{
WORD_LIST *releaser, *list;
SHELL_VAR *v;
char *identifier;
int retval, save_line_number;
#if 0
SHELL_VAR *old_value = (SHELL_VAR *)NULL; /* Remember the old value of x. */
#endif
save_line_number = line_number;
line_number = for_command->line; /* for expansion error messages */
if (check_identifier (for_command->name, 1) == 0)
{
line_number = save_line_number;
if (posixly_correct && interactive_shell == 0)
{
last_command_exit_value = EX_BADUSAGE;
jump_to_top_level (ERREXIT);
}
return (EXECUTION_FAILURE);
}
loop_level++; interrupt_execution++; retain_fifos++;
identifier = for_command->name->word;
list = releaser = expand_words_no_vars (for_command->map_list);
begin_unwind_frame ("for");
add_unwind_protect (uw_dispose_words, releaser);
add_unwind_protect (uw_restore_lineno, (void *) (intptr_t) save_line_number);
#if 0
if (lexical_scoping)
{
old_value = copy_variable (find_variable (identifier));
if (old_value)
add_unwind_protect (uw_dispose_variable, old_value);
}
#endif
if (for_command->flags & CMD_IGNORE_RETURN)
for_command->action->flags |= CMD_IGNORE_RETURN;
for (retval = EXECUTION_SUCCESS; list; list = list->next)
{
QUIT;
line_number = for_command->line;
/* Remember what this command looks like, for debugger. */
command_string_index = 0;
print_for_command_head (for_command);
/* Save this command unless it's a trap command and we're not running
a debug trap. */
if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
{
FREE (the_printed_command_except_trap);
the_printed_command_except_trap = savestring (the_printed_command);
}
retval = run_debug_trap ();
#if defined (DEBUGGER)
/* In debugging mode, if the DEBUG trap returns a non-zero status, we
skip the command. */
if (debugging_mode && retval != EXECUTION_SUCCESS)
continue;
#endif
if (echo_command_at_execute)
xtrace_print_for_command_head (for_command);
this_command_name = (char *)NULL;
/* XXX - special ksh93 for command index variable handling */
v = find_variable_last_nameref (identifier, 1);
if (v && nameref_p (v))
{
if (valid_nameref_value (list->word->word, 1) == 0)
{
sh_invalidid (list->word->word);
v = 0;
}
else if (readonly_p (v))
err_readonly (name_cell (v));
else
v = bind_variable_value (v, list->word->word, ASS_NAMEREF);
}
else
v = bind_variable (identifier, list->word->word, 0);
if (v == 0 || ASSIGN_DISALLOWED (v, 0))
{
line_number = save_line_number;
if (v && readonly_p (v) && interactive_shell == 0 && posixly_correct)
{
last_command_exit_value = EXECUTION_FAILURE;
jump_to_top_level (FORCE_EOF);
}
else
{
dispose_words (releaser);
discard_unwind_frame ("for");
loop_level--; interrupt_execution--; retain_fifos--;
return (EXECUTION_FAILURE);
}
}
if (ifsname (identifier))
setifs (v);
else
stupidly_hack_special_variables (identifier);
retval = execute_command (for_command->action);
REAP ();
QUIT;
if (breaking)
{
breaking--;
break;
}
if (continuing)
{
continuing--;
if (continuing)
break;
}
}
loop_level--; interrupt_execution--; retain_fifos--;
line_number = save_line_number;
#if 0
if (lexical_scoping)
{
if (!old_value)
unbind_variable (identifier);
else
{
SHELL_VAR *new_value;
new_value = bind_variable (identifier, value_cell (old_value), 0);
new_value->attributes = old_value->attributes;
dispose_variable (old_value);
}
}
#endif
dispose_words (releaser);
discard_unwind_frame ("for");
return (retval);
}
#if defined (ARITH_FOR_COMMAND)
/* Execute an arithmetic for command. The syntax is
for (( init ; step ; test ))
do
body
done
The execution should be exactly equivalent to
eval \(\( init \)\)
while eval \(\( test \)\) ; do
body;
eval \(\( step \)\)
done
*/
static intmax_t
eval_arith_for_expr (WORD_LIST *l, int *okp)
{
WORD_LIST *new;
intmax_t expresult;
int r, eflag;
char *expr, *temp;
expr = l->next ? string_list (l) : l->word->word;
temp = expand_arith_string (expr, Q_DOUBLE_QUOTES|Q_ARITH);
if (l->next)
free (expr);
new = make_word_list (make_word (temp ? temp : ""), (WORD_LIST *)NULL);
free (temp);
if (new)
{
command_string_index = 0;
print_arith_command (new);
if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
{
FREE (the_printed_command_except_trap);
the_printed_command_except_trap = savestring (the_printed_command);
}
r = run_debug_trap ();
#if defined (DEBUGGER)
/* In debugging mode, if the DEBUG trap returns a non-zero status, we
skip the command. */
if (debugging_mode && r != EXECUTION_SUCCESS)
{
expresult = 0;
if (okp)
*okp = 1;
return (expresult);
}
#endif
if (echo_command_at_execute)
xtrace_print_arith_cmd (new);
eflag = (shell_compatibility_level > 51) ? 0 : EXP_EXPANDED;
this_command_name = "(("; /* )) for expression error messages */
expresult = evalexp (new->word->word, eflag, okp);
dispose_words (new);
}
else
{
expresult = 0;
if (okp)
*okp = 1;
}
return (expresult);
}
static int
execute_arith_for_command (ARITH_FOR_COM *arith_for_command)
{
intmax_t expresult;
int expok, body_status, arith_lineno, save_lineno;
body_status = EXECUTION_SUCCESS;
loop_level++; interrupt_execution++;
save_lineno = line_number;
if (arith_for_command->flags & CMD_IGNORE_RETURN)
arith_for_command->action->flags |= CMD_IGNORE_RETURN;
this_command_name = "(("; /* )) for expression error messages */
/* save the starting line number of the command so we can reset
line_number before executing each expression -- for $LINENO
and the DEBUG trap. */
line_number = arith_lineno = arith_for_command->line;
ADJUST_LINE_NUMBER ();
/* Evaluate the initialization expression. */
expresult = eval_arith_for_expr (arith_for_command->init, &expok);
while (expok)
{
/* Evaluate the test expression. */
line_number = arith_lineno;
expresult = eval_arith_for_expr (arith_for_command->test, &expok);
line_number = save_lineno;
/* If the step or test expressions execute `break' or `continue' in a
nofork command substitution or by some other means, break the loop
here. */
if (breaking)
{
breaking--;
break;
}
if (continuing)
{
continuing--;
if (continuing)
break;
}
if (expok == 0)
break;
REAP ();
if (expresult == 0)
break;
/* Execute the body of the arithmetic for command. */
QUIT;
body_status = execute_command (arith_for_command->action);
QUIT;
/* Handle any `break' or `continue' commands executed by the body. */
if (breaking)
{
breaking--;
break;
}
if (continuing)
{
continuing--;
if (continuing)
break;
}
/* Evaluate the step expression. */
line_number = arith_lineno;
expresult = eval_arith_for_expr (arith_for_command->step, &expok);
line_number = save_lineno;
}
loop_level--; interrupt_execution--;
line_number = save_lineno;
return (expok ? body_status : EXECUTION_FAILURE);
}
#endif
#if defined (SELECT_COMMAND)
static int LINES, COLS, tabsize;
#define RP_SPACE ") "
#define RP_SPACE_LEN 2
/* XXX - does not handle numbers > 1000000 at all. */
#define NUMBER_LEN(s) \
((s < 10) ? 1 \
: ((s < 100) ? 2 \
: ((s < 1000) ? 3 \
: ((s < 10000) ? 4 \
: ((s < 100000) ? 5 \
: 6)))))
static int
displen (const char *s)
{
#if defined (HANDLE_MULTIBYTE)
wchar_t *wcstr;
size_t slen;
int wclen;
wcstr = 0;
slen = mbstowcs (wcstr, s, 0);
if (slen == -1)
slen = 0;
wcstr = (wchar_t *)xmalloc (sizeof (wchar_t) * (slen + 1));
mbstowcs (wcstr, s, slen + 1);
wclen = wcswidth (wcstr, slen);
free (wcstr);
return (wclen < 0 ? STRLEN(s) : wclen);
#else
return (STRLEN (s));
#endif
}
static int
print_index_and_element (int len, int ind, WORD_LIST *list)
{
WORD_LIST *l;
int i;
if (list == 0)
return (0);
for (i = ind, l = list; l && --i; l = l->next)
;
if (l == 0) /* don't think this can happen */
return (0);
fprintf (stderr, "%*d%s%s", len, ind, RP_SPACE, l->word->word);
return (displen (l->word->word));
}
static void
indent (int from, int to)
{
while (from < to)
{
if ((to / tabsize) > (from / tabsize))
{
putc ('\t', stderr);
from += tabsize - from % tabsize;
}
else
{
putc (' ', stderr);
from++;
}
}
}
static void
print_select_list (WORD_LIST *list, int list_len, int max_elem_len, int indices_len)
{
int ind, row, elem_len, pos, cols, rows;
int first_column_indices_len, other_indices_len;
if (list == 0)
{
putc ('\n', stderr);
return;
}
cols = max_elem_len ? COLS / max_elem_len : 1;
if (cols == 0)
cols = 1;
rows = list_len ? list_len / cols + (list_len % cols != 0) : 1;
cols = list_len ? list_len / rows + (list_len % rows != 0) : 1;
if (rows == 1)
{
rows = cols;
cols = 1;
}
first_column_indices_len = NUMBER_LEN (rows);
other_indices_len = indices_len;
for (row = 0; row < rows; row++)
{
ind = row;
pos = 0;
while (1)
{
indices_len = (pos == 0) ? first_column_indices_len : other_indices_len;
elem_len = print_index_and_element (indices_len, ind + 1, list);
elem_len += indices_len + RP_SPACE_LEN;
ind += rows;
if (ind >= list_len)
break;
indent (pos + elem_len, pos + max_elem_len);
pos += max_elem_len;
}
putc ('\n', stderr);
}
}
/* Print the elements of LIST, one per line, preceded by an index from 1 to
LIST_LEN. Then display PROMPT and wait for the user to enter a number.
If the number is between 1 and LIST_LEN, return that selection. If EOF
is read, return a null string. If a blank line is entered, or an invalid
number is entered, the loop is executed again. */
static char *
select_query (WORD_LIST *list, int list_len, char *prompt, int print_menu)
{
int max_elem_len, indices_len, len, r, oe;
intmax_t reply;
WORD_LIST *l;
char *repl_string, *t;
COLS = default_columns ();
#if 0
t = get_string_value ("TABSIZE");
tabsize = (t && *t) ? atoi (t) : 8;
if (tabsize <= 0)
tabsize = 8;
#else
tabsize = 8;
#endif
max_elem_len = 0;
for (l = list; l; l = l->next)
{
len = displen (l->word->word);
if (len > max_elem_len)
max_elem_len = len;
}
indices_len = NUMBER_LEN (list_len);
max_elem_len += indices_len + RP_SPACE_LEN + 2;
while (1)
{
if (print_menu)
print_select_list (list, list_len, max_elem_len, indices_len);
fprintf (stderr, "%s", prompt);
fflush (stderr);
QUIT;
oe = executing_builtin;
executing_builtin = 1;
r = read_builtin ((WORD_LIST *)NULL);
executing_builtin = oe;
if (r != EXECUTION_SUCCESS)
{
putchar ('\n');
return ((char *)NULL);
}
repl_string = get_string_value ("REPLY");
if (repl_string == 0)
return ((char *)NULL);
if (*repl_string == 0)
{
print_menu = 1;
continue;
}
if (valid_number (repl_string, &reply) == 0)
return "";
if (reply < 1 || reply > list_len)
return "";
for (l = list; l && --reply; l = l->next)
;
return (l->word->word); /* XXX - can't be null? */
}
}
/* Execute a SELECT command. The syntax is:
SELECT word IN list DO command_list DONE
Only `break' or `return' in command_list will terminate
the command. */
static int
execute_select_command (SELECT_COM *select_command)
{
WORD_LIST *releaser, *list;
SHELL_VAR *v;
char *identifier, *ps3_prompt, *selection;
int retval, list_len, show_menu, save_line_number;
if (check_identifier (select_command->name, 1) == 0)
{
if (posixly_correct && interactive_shell == 0)
{
last_command_exit_value = EX_BADUSAGE;
jump_to_top_level (ERREXIT);
}
return (EXECUTION_FAILURE);
}
save_line_number = line_number;
line_number = select_command->line;
command_string_index = 0;
print_select_command_head (select_command);
#if 0
if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
#else
if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
#endif
{
FREE (the_printed_command_except_trap);
the_printed_command_except_trap = savestring (the_printed_command);
}
retval = run_debug_trap ();
#if defined (DEBUGGER)
/* In debugging mode, if the DEBUG trap returns a non-zero status, we
skip the command. */
if (debugging_mode && retval != EXECUTION_SUCCESS)
return (EXECUTION_SUCCESS);
#endif
if (echo_command_at_execute)
xtrace_print_select_command_head (select_command);
this_command_name = (char *)0;
loop_level++; interrupt_execution++;
identifier = select_command->name->word;
/* command and arithmetic substitution, parameter and variable expansion,
word splitting, pathname expansion, and quote removal. */
list = releaser = expand_words_no_vars (select_command->map_list);
list_len = list_length ((GENERIC_LIST *)list);
if (list == 0 || list_len == 0)
{
if (list)
dispose_words (list);
line_number = save_line_number;
return (EXECUTION_SUCCESS);
}
begin_unwind_frame ("select");
add_unwind_protect (uw_dispose_words, releaser);
add_unwind_protect (uw_restore_lineno, (void *) (intptr_t) save_line_number);
if (select_command->flags & CMD_IGNORE_RETURN)
select_command->action->flags |= CMD_IGNORE_RETURN;
retval = EXECUTION_SUCCESS;
show_menu = 1;
while (1)
{
line_number = select_command->line;
ps3_prompt = get_string_value ("PS3");
if (ps3_prompt == 0)
ps3_prompt = "#? ";
QUIT;
selection = select_query (list, list_len, ps3_prompt, show_menu);
QUIT;
if (selection == 0)
{
/* select_query returns EXECUTION_FAILURE if the read builtin
fails, so we want to return failure in this case. */
retval = EXECUTION_FAILURE;
break;
}
v = bind_variable (identifier, selection, 0);
if (v == 0 || ASSIGN_DISALLOWED (v, 0))
{
if (v && readonly_p (v) && interactive_shell == 0 && posixly_correct)
{
last_command_exit_value = EXECUTION_FAILURE;
jump_to_top_level (FORCE_EOF);
}
else
{
dispose_words (releaser);
discard_unwind_frame ("select");
loop_level--; interrupt_execution--;
line_number = save_line_number;
return (EXECUTION_FAILURE);
}
}
stupidly_hack_special_variables (identifier);
retval = execute_command (select_command->action);
REAP ();
QUIT;
if (breaking)
{
breaking--;
break;
}
if (continuing)
{
continuing--;
if (continuing)
break;
}
#if defined (KSH_COMPATIBLE_SELECT)
show_menu = 0;
selection = get_string_value ("REPLY");
if (selection && *selection == '\0')
show_menu = 1;
#endif
}
loop_level--; interrupt_execution--;
line_number = save_line_number;
dispose_words (releaser);
discard_unwind_frame ("select");
return (retval);
}
#endif /* SELECT_COMMAND */
/* Execute a CASE command. The syntax is: CASE word_desc IN pattern_list ESAC.
The pattern_list is a linked list of pattern clauses; each clause contains
some patterns to compare word_desc against, and an associated command to
execute. */
static int
execute_case_command (CASE_COM *case_command)
{
WORD_LIST *list;
WORD_LIST *wlist, *es;
PATTERN_LIST *clauses;
char *word, *pattern;
int retval, match, ignore_return, save_line_number, qflags;
save_line_number = line_number;
line_number = case_command->line;
command_string_index = 0;
print_case_command_head (case_command);
#if 0
if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
#else
if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
#endif
{
FREE (the_printed_command_except_trap);
the_printed_command_except_trap = savestring (the_printed_command);
}
retval = run_debug_trap();
#if defined (DEBUGGER)
/* In debugging mode, if the DEBUG trap returns a non-zero status, we
skip the command. */
if (debugging_mode && retval != EXECUTION_SUCCESS)
{
line_number = save_line_number;
return (EXECUTION_SUCCESS);
}
#endif
if (echo_command_at_execute)
xtrace_print_case_command_head (case_command);
/* Use the same expansions (the ones POSIX specifies) as the patterns;
dequote the resulting string (as POSIX specifies) since the quotes in
patterns are handled specially below. We have to do it in this order
because we're not supposed to perform word splitting. */
wlist = expand_word_leave_quoted (case_command->word, 0);
if (wlist)
{
char *t;
t = string_list (wlist);
word = dequote_string (t);
free (t);
}
else
word = savestring ("");
dispose_words (wlist);
retval = EXECUTION_SUCCESS;
ignore_return = case_command->flags & CMD_IGNORE_RETURN;
begin_unwind_frame ("case");
add_unwind_protect (xfree, word);
add_unwind_protect (uw_restore_lineno, (void *) (intptr_t) save_line_number);
#define EXIT_CASE() goto exit_case_command
for (clauses = case_command->clauses; clauses; clauses = clauses->next)
{
QUIT;
for (list = clauses->patterns; list; list = list->next)
{
es = expand_word_leave_quoted (list->word, 0);
if (es && es->word && es->word->word && *(es->word->word))
{
/* Convert quoted null strings into empty strings. */
qflags = QGLOB_CVTNULL;
/* We left CTLESC in place quoting CTLESC and CTLNUL after the
call to expand_word_leave_quoted; tell quote_string_for_globbing
to remove those here. This works for both unquoted portions of
the word (which call quote_escapes) and quoted portions
(which call quote_string). */
qflags |= QGLOB_CTLESC;
pattern = quote_string_for_globbing (es->word->word, qflags);
}
else
{
pattern = (char *)xmalloc (1);
pattern[0] = '\0';
}
/* Since the pattern does not undergo quote removal (as per
Posix.2, section 3.9.4.3), the strmatch () call must be able
to recognize backslashes as escape characters. */
match = strmatch (pattern, word, FNMATCH_EXTFLAG|FNMATCH_IGNCASE) != FNM_NOMATCH;
free (pattern);
dispose_words (es);
/* sm_loop.c:GMATCH returns failure on interrupt_state or
terminating_signal, so we check for those here. */
QUIT;
if (match)
{
do
{
if (clauses->action && ignore_return)
clauses->action->flags |= CMD_IGNORE_RETURN;
retval = execute_command (clauses->action);
}
while ((clauses->flags & CASEPAT_FALLTHROUGH) && (clauses = clauses->next));
if (clauses == 0 || (clauses->flags & CASEPAT_TESTNEXT) == 0)
EXIT_CASE ();
else
break;
}
QUIT;
}
}
exit_case_command:
free (word);
discard_unwind_frame ("case");
line_number = save_line_number;
return (retval);
}
#define CMD_WHILE 0
#define CMD_UNTIL 1
/* The WHILE command. Syntax: WHILE test DO action; DONE.
Repeatedly execute action while executing test produces
EXECUTION_SUCCESS. */
static int
execute_while_command (WHILE_COM *while_command)
{
return (execute_while_or_until (while_command, CMD_WHILE));
}
/* UNTIL is just like WHILE except that the test result is negated. */
static int
execute_until_command (WHILE_COM *while_command)
{
return (execute_while_or_until (while_command, CMD_UNTIL));
}
/* The body for both while and until. The only difference between the
two is that the test value is treated differently. TYPE is
CMD_WHILE or CMD_UNTIL. The return value for both commands should
be EXECUTION_SUCCESS if no commands in the body are executed, and
the status of the last command executed in the body otherwise. */
static int
execute_while_or_until (WHILE_COM *while_command, int type)
{
int return_value, body_status;
body_status = EXECUTION_SUCCESS;
loop_level++; interrupt_execution++;
while_command->test->flags |= CMD_IGNORE_RETURN;
if (while_command->flags & CMD_IGNORE_RETURN)
while_command->action->flags |= CMD_IGNORE_RETURN;
while (1)
{
return_value = execute_command (while_command->test);
/* Need to handle `break' in the test when we would break out of the
loop. The job control code will set `breaking' to loop_level
when a job in a loop is stopped with SIGTSTP. If the stopped job
is in the loop test, `breaking' will not be reset unless we do
this, and the shell will cease to execute commands. The same holds
true for `continue'. */
if (type == CMD_WHILE && return_value != EXECUTION_SUCCESS)
{
if (breaking)
breaking--;
if (continuing)
continuing--;
break;
}
if (type == CMD_UNTIL && return_value == EXECUTION_SUCCESS)
{
if (breaking)
breaking--;
if (continuing)
continuing--;
break;
}
QUIT;
body_status = execute_command (while_command->action);
QUIT;
REAP ();
if (breaking)
{
breaking--;
break;
}
if (continuing)
{
continuing--;
if (continuing)
break;
}
}
loop_level--; interrupt_execution--;
return (body_status);
}
/* IF test THEN command [ELSE command].
IF also allows ELIF in the place of ELSE IF, but
the parser makes *that* stupidity transparent. */
static int
execute_if_command (IF_COM *if_command)
{
int return_value, save_line_number;
save_line_number = line_number;
if_command->test->flags |= CMD_IGNORE_RETURN;
return_value = execute_command (if_command->test);
line_number = save_line_number;
if (return_value == EXECUTION_SUCCESS)
{
QUIT;
if (if_command->true_case && (if_command->flags & CMD_IGNORE_RETURN))
if_command->true_case->flags |= CMD_IGNORE_RETURN;
return (execute_command (if_command->true_case));
}
else
{
QUIT;
if (if_command->false_case && (if_command->flags & CMD_IGNORE_RETURN))
if_command->false_case->flags |= CMD_IGNORE_RETURN;
return (execute_command (if_command->false_case));
}
}
#if defined (DPAREN_ARITHMETIC)
static int
execute_arith_command (ARITH_COM *arith_command)
{
int expok, save_line_number, retval, eflag;
intmax_t expresult;
WORD_LIST *new;
char *exp, *t;
expresult = 0;
save_line_number = line_number;
this_command_name = "(("; /* )) */
SET_LINE_NUMBER (arith_command->line);
/* If we're in a function, update the line number information. */
ADJUST_LINE_NUMBER ();
command_string_index = 0;
print_arith_command (arith_command->exp);
if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
{
FREE (the_printed_command_except_trap);
the_printed_command_except_trap = savestring (the_printed_command);
}
/* Run the debug trap before each arithmetic command, but do it after we
update the line number information and before we expand the various
words in the expression. */
retval = run_debug_trap ();
#if defined (DEBUGGER)
/* In debugging mode, if the DEBUG trap returns a non-zero status, we
skip the command. */
if (debugging_mode && retval != EXECUTION_SUCCESS)
{
line_number = save_line_number;
return (EXECUTION_SUCCESS);
}
#endif
this_command_name = "(("; /* )) */
t = (char *)NULL;
new = arith_command->exp;
exp = (new->next) ? (t = string_list (new)) : new->word->word;
exp = expand_arith_string (exp, Q_DOUBLE_QUOTES|Q_ARITH);
FREE (t);
/* If we're tracing, make a new word list with `((' at the front and `))'
at the back and print it. Change xtrace_print_arith_cmd to take a string
when I change eval_arith_for_expr to use expand_arith_string(). */
if (echo_command_at_execute)
{
new = make_word_list (make_word (exp ? exp : ""), (WORD_LIST *)NULL);
xtrace_print_arith_cmd (new);
dispose_words (new);
}
if (exp)
{
eflag = (shell_compatibility_level > 51) ? 0 : EXP_EXPANDED;
expresult = evalexp (exp, eflag, &expok);
line_number = save_line_number;
free (exp);
}
else
{
expresult = 0;
expok = 1;
}
if (expok == 0)
return (EXECUTION_FAILURE);
return (expresult == 0 ? EXECUTION_FAILURE : EXECUTION_SUCCESS);
}
#endif /* DPAREN_ARITHMETIC */
#if defined (COND_COMMAND)
static char * const nullstr = "";
/* XXX - can COND ever be NULL when this is called? */
static int
execute_cond_node (COND_COM *cond)
{
int result, invert, patmatch, rmatch, arith, mode, mflags, ignore;
char *arg1, *arg2, *op;
#if 0
char *t1, *t2;
#endif
invert = (cond->flags & CMD_INVERT_RETURN);
ignore = (cond->flags & CMD_IGNORE_RETURN);
if (ignore)
{
if (cond->left)
cond->left->flags |= CMD_IGNORE_RETURN;
if (cond->right)
cond->right->flags |= CMD_IGNORE_RETURN;
}
if (cond->type == COND_EXPR)
result = execute_cond_node (cond->left);
else if (cond->type == COND_OR)
{
result = execute_cond_node (cond->left);
if (result != EXECUTION_SUCCESS)
result = execute_cond_node (cond->right);
}
else if (cond->type == COND_AND)
{
result = execute_cond_node (cond->left);
if (result == EXECUTION_SUCCESS)
result = execute_cond_node (cond->right);
}
else if (cond->type == COND_UNARY)
{
int oa, varop, varflag;
if (ignore)
comsub_ignore_return++;
varop = STREQ (cond->op->word, "-v");
#if defined (ARRAY_VARS)
varflag = (varop && valid_array_reference (cond->left->op->word, VA_NOEXPAND)) ? TEST_ARRAYEXP : 0;
#else
varflag = 0;
#endif
arg1 = cond_expand_word (cond->left->op, varop ? 3 : 0);
if (ignore)
comsub_ignore_return--;
if (arg1 == 0)
arg1 = nullstr;
if (echo_command_at_execute)
xtrace_print_cond_term (cond->type, invert, cond->op, arg1, (char *)NULL);
#if defined (ARRAY_VARS)
if (varop)
oa = set_expand_once (0, 0); /* no-op for compatibility levels <= 51 */
#endif
result = cond_test (cond->op->word, arg1, NULL, varflag);
#if defined (ARRAY_VARS)
if (varop)
array_expand_once = oa;
#endif
if (arg1 != nullstr)
free (arg1);
}
else if (cond->type == COND_BINARY)
{
rmatch = 0;
op = cond->op->word;
mode = 0;
patmatch = (((op[1] == '=') && (op[2] == '\0') &&
(op[0] == '!' || op[0] == '=')) ||
(op[0] == '=' && op[1] == '\0'));
#if defined (COND_REGEXP)
rmatch = (op[0] == '=' && op[1] == '~' && op[2] == '\0');
#endif
arith = STREQ (op, "-eq") || STREQ (op, "-ne") || STREQ (op, "-lt") ||
STREQ (op, "-le") || STREQ (op, "-gt") || STREQ (op, "-ge");
if (arith)
mode = 3;
else if (rmatch && shell_compatibility_level > 31)
mode = 2;
else if (patmatch)
mode = 1;
if (ignore)
comsub_ignore_return++;
arg1 = cond_expand_word (cond->left->op, arith ? mode : 0);
if (ignore)
comsub_ignore_return--;
if (arg1 == 0)
arg1 = nullstr;
if (ignore)
comsub_ignore_return++;
arg2 = cond_expand_word (cond->right->op, mode);
if (ignore)
comsub_ignore_return--;
if (arg2 == 0)
arg2 = nullstr;
if (echo_command_at_execute)
xtrace_print_cond_term (cond->type, invert, cond->op, arg1, arg2);
#if defined (COND_REGEXP)
if (rmatch)
{
char *errstr;
mflags = SHMAT_PWARN;
#if defined (ARRAY_VARS)
mflags |= SHMAT_SUBEXP;
#endif
#if 0
t1 = strescape(arg1);
t2 = strescape(arg2);
itrace("execute_cond_node: sh_regmatch on `%s' and `%s'", t1, t2);
free(t1);
free(t2);
#endif
errstr = NULL;
result = sh_regmatch (arg1, arg2, mflags, &errstr);
if (result == 2)
{
if (errstr && *errstr)
builtin_error (_("invalid regular expression `%s': %s"), arg2, errstr);
else
builtin_error (_("invalid regular expression `%s'"), arg2);
free (errstr);
}
}
else
#endif /* COND_REGEXP */
{
extended_glob = 1;
result = cond_test (cond->op->word, arg1, arg2, TEST_PATMATCH|TEST_ARITHEXP|TEST_LOCALE);
extended_glob = extglob_flag;
}
if (arg1 != nullstr)
free (arg1);
if (arg2 != nullstr)
free (arg2);
}
else
{
command_error ("execute_cond_node", CMDERR_BADTYPE, cond->type, 0);
jump_to_top_level (DISCARD);
result = EXECUTION_FAILURE;
}
if (invert)
result = (result == EXECUTION_SUCCESS) ? EXECUTION_FAILURE : EXECUTION_SUCCESS;
return result;
}
static int
execute_cond_command (COND_COM *cond_command)
{
int retval, save_line_number;
save_line_number = line_number;
SET_LINE_NUMBER (cond_command->line);
/* If we're in a function, update the line number information. */
ADJUST_LINE_NUMBER ();
command_string_index = 0;
print_cond_command (cond_command);
if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
{
FREE (the_printed_command_except_trap);
the_printed_command_except_trap = savestring (the_printed_command);
}
/* Run the debug trap before each conditional command, but do it after we
update the line number information. */
retval = run_debug_trap ();
#if defined (DEBUGGER)
/* In debugging mode, if the DEBUG trap returns a non-zero status, we
skip the command. */
if (debugging_mode && retval != EXECUTION_SUCCESS)
{
line_number = save_line_number;
return (EXECUTION_SUCCESS);
}
#endif
this_command_name = "[["; /* ]] */
#if 0
debug_print_cond_command (cond_command);
#endif
last_command_exit_value = retval = execute_cond_node (cond_command);
line_number = save_line_number;
return (retval);
}
#endif /* COND_COMMAND */
char *
save_lastarg (void)
{
char *v;
v = get_string_value ("_");
if (v)
v = savestring (v);
return v;
}
void
bind_lastarg (char *arg)
{
SHELL_VAR *var;
if (arg == 0)
arg = "";
var = bind_variable ("_", arg, 0);
if (var)
VUNSETATTR (var, att_exported);
}
/* Execute a null command. Fork a subshell if the command uses pipes or is
to be run asynchronously. This handles all the side effects that are
supposed to take place. */
static int
execute_null_command (REDIRECT *redirects, int pipe_in, int pipe_out, int async)
{
int r, code;
int forcefork, fork_flags;
REDIRECT *rd;
for (forcefork = 0, rd = redirects; rd; rd = rd->next)
{
forcefork += rd->rflags & REDIR_VARASSIGN;
/* Safety */
forcefork += (rd->redirector.dest == 0 || fd_is_bash_input (rd->redirector.dest));
}
if (forcefork || pipe_in != NO_PIPE || pipe_out != NO_PIPE || async)
{
/* We have a null command, but we really want a subshell to take
care of it. Just fork, do piping and redirections, and exit. */
fork_flags = async ? FORK_ASYNC : 0;
if (make_child ((char *)NULL, fork_flags) == 0)
{
/* Cancel traps, in trap.c. */
restore_original_signals (); /* XXX */
do_piping (pipe_in, pipe_out);
#if defined (COPROCESS_SUPPORT)
coproc_closeall ();
#endif
interactive = 0; /* XXX */
subshell_environment = 0;
if (async)
subshell_environment |= SUBSHELL_ASYNC;
if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
subshell_environment |= SUBSHELL_PIPE;
code = setjmp_nosigs (top_level);
if (code)
exit (EXECUTION_FAILURE);
if (do_redirections (redirects, RX_ACTIVE) == 0)
exit (EXECUTION_SUCCESS);
else
exit (EXECUTION_FAILURE);
}
else
{
close_pipes (pipe_in, pipe_out);
#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
if (pipe_out == NO_PIPE)
unlink_fifo_list ();
#endif
return (EXECUTION_SUCCESS);
}
}
else
{
/* Even if there aren't any command names, pretend to do the
redirections that are specified. The user expects the side
effects to take place. If the redirections fail, then return
failure. Otherwise, if a command substitution took place while
expanding the command or a redirection, return the value of that
substitution. Otherwise, return EXECUTION_SUCCESS. */
r = do_redirections (redirects, RX_ACTIVE|RX_UNDOABLE);
cleanup_redirects (redirection_undo_list);
redirection_undo_list = (REDIRECT *)NULL;
if (r != 0)
return (EXECUTION_FAILURE);
else if (last_command_subst_pid != NO_PID)
return (last_command_subst_status);
else
return (EXECUTION_SUCCESS);
}
}
/* This is a hack to suppress word splitting for assignment statements
given as arguments to builtins with the ASSIGNMENT_BUILTIN flag set. */
static void
fix_assignment_words (WORD_LIST *words)
{
WORD_LIST *w, *wcmd;
struct builtin *b;
int assoc, global, array;
if (words == 0)
return;
b = 0;
assoc = global = array = 0;
/* Skip over assignment statements preceding a command name */
wcmd = words;
for (wcmd = words; wcmd; wcmd = wcmd->next)
if ((wcmd->word->flags & W_ASSIGNMENT) == 0)
break;
/* Posix (post-2008) says that `command' doesn't change whether
or not the builtin it shadows is a `declaration command', even
though it removes other special builtin properties. In Posix
mode, we skip over one or more instances of `command' and
deal with the next word as the assignment builtin. */
while (posixly_correct && wcmd && wcmd->word && wcmd->word->word && STREQ (wcmd->word->word, "command"))
wcmd = wcmd->next;
for (w = wcmd; w; w = w->next)
if (w->word->flags & W_ASSIGNMENT)
{
/* Lazy builtin lookup, only do it if we find an assignment */
if (b == 0)
{
b = builtin_address_internal (wcmd->word->word, 0);
if (b == 0 || (b->flags & ASSIGNMENT_BUILTIN) == 0)
return;
else if (b && (b->flags & ASSIGNMENT_BUILTIN))
wcmd->word->flags |= W_ASSNBLTIN;
}
w->word->flags |= (W_NOSPLIT|W_NOGLOB|W_TILDEEXP|W_ASSIGNARG);
#if defined (ARRAY_VARS)
if (assoc)
w->word->flags |= W_ASSIGNASSOC;
if (array)
w->word->flags |= W_ASSIGNARRAY;
#endif
if (global)
w->word->flags |= W_ASSNGLOBAL;
/* If we have an assignment builtin that does not create local variables,
make sure we create global variables even if we internally call
`declare'. The CHKLOCAL flag means to set attributes or values on
an existing local variable, if there is one. */
if (b && ((b->flags & (ASSIGNMENT_BUILTIN|LOCALVAR_BUILTIN)) == ASSIGNMENT_BUILTIN))
w->word->flags |= W_ASSNGLOBAL|W_CHKLOCAL;
else if (b && (b->flags & ASSIGNMENT_BUILTIN) && (b->flags & LOCALVAR_BUILTIN) && variable_context)
w->word->flags |= W_FORCELOCAL;
}
#if defined (ARRAY_VARS)
/* Note that we saw an associative array option to a builtin that takes
assignment statements. This is a bit of a kludge. */
else if (w->word->word[0] == '-' && (strpbrk (w->word->word+1, "Aag") != 0))
#else
else if (w->word->word[0] == '-' && strchr (w->word->word+1, 'g'))
#endif
{
if (b == 0)
{
b = builtin_address_internal (wcmd->word->word, 0);
if (b == 0 || (b->flags & ASSIGNMENT_BUILTIN) == 0)
return;
else if (b && (b->flags & ASSIGNMENT_BUILTIN))
wcmd->word->flags |= W_ASSNBLTIN;
}
if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'A'))
assoc = 1;
else if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'a'))
array = 1;
if ((wcmd->word->flags & W_ASSNBLTIN) && strchr (w->word->word+1, 'g'))
global = 1;
}
}
#if defined (ARRAY_VARS)
/* Set W_ARRAYREF on words that are valid array references to a builtin that
accepts them. This is intended to completely replace array_expand_once in
time. */
static void
fix_arrayref_words (WORD_LIST *words)
{
WORD_LIST *w, *wcmd;
struct builtin *b;
if (words == 0)
return;
b = 0;
/* Skip over assignment statements preceding a command name */
wcmd = words;
for (wcmd = words; wcmd; wcmd = wcmd->next)
if ((wcmd->word->flags & W_ASSIGNMENT) == 0)
break;
/* Skip over `command' */
while (wcmd && wcmd->word && wcmd->word->word && STREQ (wcmd->word->word, "command"))
wcmd = wcmd->next;
if (wcmd == 0)
return;
/* If it's not an array reference builtin, we have nothing to do. */
b = builtin_address_internal (wcmd->word->word, 0);
if (b == 0 || (b->flags & ARRAYREF_BUILTIN) == 0)
return;
for (w = wcmd->next; w; w = w->next)
{
if (w->word && w->word->word && valid_array_reference (w->word->word, 0))
w->word->flags |= W_ARRAYREF;
}
}
#endif
#ifndef ISOPTION
# define ISOPTION(s, c) (s[0] == '-' && s[1] == c && s[2] == 0)
#endif
#define RETURN_NOT_COMMAND() \
do { if (typep) *typep = 0; return words; } while (0)
/* Make sure we have `command [-p] command_name [args]', and handle skipping
over the usual `--' that ends the options. Returns the updated WORDS with
the command and options stripped and sets *TYPEP to a non-zero value. If
any other options are supplied, or there is not a command_name, we punt
and return a zero value in *TYPEP without updating WORDS. */
static WORD_LIST *
check_command_builtin (WORD_LIST *words, int *typep)
{
int type;
WORD_LIST *w;
w = words->next;
type = 1;
if (w && ISOPTION (w->word->word, 'p')) /* command -p */
{
#if defined (RESTRICTED_SHELL)
if (restricted)
RETURN_NOT_COMMAND();
#endif
w = w->next;
type = 2;
}
if (w && ISOPTION (w->word->word, '-')) /* command [-p] -- */
w = w->next;
else if (w && w->word->word[0] == '-') /* any other option */
RETURN_NOT_COMMAND();
if (w == 0 || w->word->word == 0) /* must have a command_name */
RETURN_NOT_COMMAND();
if (typep)
*typep = type;
return w;
}
/* Return 1 if the file found by searching $PATH for PATHNAME, defaulting
to PATHNAME, is a directory. Used by the autocd code below. */
static int
is_dirname (char *pathname)
{
char *temp;
int ret;
temp = search_for_command (pathname, 0);
ret = temp ? file_isdir (temp) : file_isdir (pathname);
free (temp);
return ret;
}
/* The meaty part of all the executions. We have to start hacking the
real execution of commands here. Fork a process, set things up,
execute the command. */
static int
execute_simple_command (SIMPLE_COM *simple_command, int pipe_in, int pipe_out, int async, struct fd_bitmap *fds_to_close)
{
WORD_LIST *words, *lastword;
char *command_line, *lastarg, *temp;
int first_word_quoted, result, builtin_is_special, already_forked, dofork;
int fork_flags, cmdflags;
pid_t old_last_async_pid;
sh_builtin_func_t *builtin;
SHELL_VAR *func;
volatile int old_builtin, old_command_builtin;
result = EXECUTION_SUCCESS;
special_builtin_failed = builtin_is_special = 0;
command_line = (char *)0;
QUIT;
/* If we're in a function, update the line number information. */
ADJUST_LINE_NUMBER ();
/* Remember what this command line looks like at invocation. */
command_string_index = 0;
if (the_printed_command)
the_printed_command[0] = '\0';
print_simple_command (simple_command);
#if 0
if (signal_in_progress (DEBUG_TRAP) == 0 && (this_command_name == 0 || (STREQ (this_command_name, "trap") == 0)))
#else
if (signal_in_progress (DEBUG_TRAP) == 0 && running_trap == 0)
#endif
{
FREE (the_printed_command_except_trap);
the_printed_command_except_trap = the_printed_command ? savestring (the_printed_command) : (char *)0;
}
/* Run the debug trap before each simple command, but do it after we
update the line number information. */
result = run_debug_trap ();
#if defined (DEBUGGER)
/* In debugging mode, if the DEBUG trap returns a non-zero status, we
skip the command. */
if (debugging_mode && result != EXECUTION_SUCCESS)
return (EXECUTION_SUCCESS);
#endif
cmdflags = simple_command->flags;
first_word_quoted =
simple_command->words ? (simple_command->words->word->flags & W_QUOTED) : 0;
last_command_subst_pid = NO_PID;
old_last_async_pid = last_asynchronous_pid;
already_forked = 0;
/* If we're in a pipeline or run in the background, set DOFORK so we
make the child early, before word expansion. This keeps assignment
statements from affecting the parent shell's environment when they
should not. */
dofork = pipe_in != NO_PIPE || pipe_out != NO_PIPE || async;
/* Something like `%2 &' should restart job 2 in the background, not cause
the shell to fork here. */
if (dofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE &&
simple_command->words && simple_command->words->word &&
simple_command->words->word->word &&
(simple_command->words->word->word[0] == '%'))
dofork = 0;
if (dofork)
{
char *p, *xc;
/* Do this now, because execute_disk_command will do it anyway in the
vast majority of cases. */
maybe_make_export_env ();
/* Don't let a DEBUG trap overwrite the command string to be saved with
the process/job associated with this child. */
fork_flags = async ? FORK_ASYNC : 0;
xc = the_printed_command_except_trap;
if (make_child (p = xc ? savestring (xc) : savestring (""), fork_flags) == 0)
{
already_forked = 1;
cmdflags |= CMD_NO_FORK;
/* We redo some of what make_child() does with SUBSHELL_IGNTRAP */
subshell_environment = SUBSHELL_FORK|SUBSHELL_IGNTRAP; /* XXX */
if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
subshell_environment |= SUBSHELL_PIPE;
if (async)
subshell_environment |= SUBSHELL_ASYNC;
/* We need to do this before piping to handle some really
pathological cases where one of the pipe file descriptors
is < 2. */
if (fds_to_close)
close_fd_bitmap (fds_to_close);
/* If we fork because of an input pipe, note input pipe for later to
inhibit async commands from redirecting stdin from /dev/null */
stdin_redir |= pipe_in != NO_PIPE;
do_piping (pipe_in, pipe_out);
pipe_in = pipe_out = NO_PIPE;
#if defined (COPROCESS_SUPPORT)
coproc_closeall ();
#endif
#if defined (PROCESS_SUBSTITUTION)
clear_fifo_list (); /* subshells don't inherit fifos */
#endif
last_asynchronous_pid = old_last_async_pid;
if (async)
subshell_level++; /* not for pipes yet */
#if defined (JOB_CONTROL)
FREE (p); /* child doesn't use pointer */
#endif
}
else
{
/* Don't let simple commands that aren't the last command in a
pipeline change $? for the rest of the pipeline (or at all). */
if (pipe_out != NO_PIPE)
result = last_command_exit_value;
close_pipes (pipe_in, pipe_out);
command_line = (char *)NULL; /* don't free this. */
return (result);
}
}
QUIT; /* XXX */
/* If we are re-running this as the result of executing the `command'
builtin, do not expand the command words a second time. */
if ((cmdflags & CMD_INHIBIT_EXPANSION) == 0)
{
current_fds_to_close = fds_to_close;
fix_assignment_words (simple_command->words);
#if defined (ARRAY_VARS)
fix_arrayref_words (simple_command->words);
#endif
/* Pass the ignore return flag down to command substitutions */
if (cmdflags & CMD_IGNORE_RETURN) /* XXX */
comsub_ignore_return++;
words = expand_words (simple_command->words);
if (cmdflags & CMD_IGNORE_RETURN)
comsub_ignore_return--;
current_fds_to_close = (struct fd_bitmap *)NULL;
}
else
words = copy_word_list (simple_command->words);
/* It is possible for WORDS not to have anything left in it.
Perhaps all the words consisted of `$foo', and there was
no variable `$foo'. */
if (words == 0)
{
this_command_name = 0;
result = execute_null_command (simple_command->redirects,
pipe_in, pipe_out,
already_forked ? 0 : async);
if (already_forked)
sh_exit (result);
else
{
bind_lastarg ((char *)NULL);
set_pipestatus_from_exit (result);
return (result);
}
}
lastarg = (char *)NULL;
begin_unwind_frame ("simple-command");
if (echo_command_at_execute && (cmdflags & CMD_COMMAND_BUILTIN) == 0)
xtrace_print_word_list (words, 1);
builtin = (sh_builtin_func_t *)NULL;
func = (SHELL_VAR *)NULL;
/* This test is still here in case we want to change the command builtin
handler code below to recursively call execute_simple_command (after
modifying the simple_command struct). */
if ((cmdflags & CMD_NO_FUNCTIONS) == 0)
{
/* Posix.2 says special builtins are found before functions. We
don't set builtin_is_special anywhere other than here, because
this path is followed only when the `command' builtin is *not*
being used, and we don't want to exit the shell if a special
builtin executed with `command builtin' fails. `command' is not
a special builtin. */
if (posixly_correct)
{
builtin = find_special_builtin (words->word->word);
if (builtin)
builtin_is_special = 1;
}
if (builtin == 0)
#if 0 /*TAG bash-5.4 rob@landley.net 5/1/2025 */
func = ((shell_compatibility_level <= 52 && posixly_correct == 0) || absolute_program (words->word->word) == 0) ? find_function (words->word->word) : 0;
#else
func = (posixly_correct == 0 || absolute_program (words->word->word) == 0) ? find_function (words->word->word) : 0;
#endif
}
/* What happens in posix mode when an assignment preceding a command name
fails. This should agree with the code in execute_cmd.c:
do_assignment_statements(), even though I don't think it's executed any
more. */
if (posixly_correct && tempenv_assign_error)
{
#if defined (DEBUG)
/* I don't know if this clause is ever executed, so let's check */
itrace("execute_simple_command: posix mode tempenv assignment error");
#endif
last_command_exit_value = EXECUTION_FAILURE;
#if defined (STRICT_POSIX)
jump_to_top_level ((interactive_shell == 0) ? FORCE_EOF : DISCARD);
#else
if (interactive_shell == 0 && builtin_is_special)
jump_to_top_level (FORCE_EOF);
else if (interactive_shell == 0)
jump_to_top_level (DISCARD); /* XXX - maybe change later */
else
jump_to_top_level (DISCARD);
#endif
}
tempenv_assign_error = 0; /* don't care about this any more */
/* This is where we handle the command builtin as a pseudo-reserved word
prefix. This allows us to optimize away forks if we can. */
old_command_builtin = -1;
if (builtin == 0 && func == 0)
{
WORD_LIST *disposer, *l;
int cmdtype;
builtin = find_shell_builtin (words->word->word);
while (builtin == command_builtin)
{
disposer = words;
cmdtype = 0;
words = check_command_builtin (words, &cmdtype);
if (cmdtype > 0) /* command -p [--] words */
{
for (l = disposer; l->next != words; l = l->next)
;
l->next = 0;
dispose_words (disposer);
cmdflags |= CMD_COMMAND_BUILTIN | CMD_NO_FUNCTIONS;
if (cmdtype == 2)
cmdflags |= CMD_STDPATH;
builtin = find_shell_builtin (words->word->word);
}
else
break;
}
if (cmdflags & CMD_COMMAND_BUILTIN)
{
old_command_builtin = executing_command_builtin;
unwind_protect_int (executing_command_builtin);
executing_command_builtin |= 1;
}
builtin = 0;
}
add_unwind_protect (uw_dispose_words, words);
QUIT;
/* Bind the last word in this command to "$_" after execution. */
for (lastword = words; lastword->next; lastword = lastword->next)
;
lastarg = lastword->word->word;
#if defined (JOB_CONTROL)
/* Is this command a job control related thing? */
if (words->word->word[0] == '%' && already_forked == 0)
{
this_command_name = async ? "bg" : "fg";
last_shell_builtin = this_shell_builtin;
this_shell_builtin = builtin_address (this_command_name);
result = (*this_shell_builtin) (words);
goto return_result;
}
/* One other possibililty. The user may want to resume an existing job.
If they do, find out whether this word is a candidate for a running
job. */
if (job_control && already_forked == 0 && async == 0 &&
!first_word_quoted &&
!words->next &&
words->word->word[0] &&
!simple_command->redirects &&
pipe_in == NO_PIPE &&
pipe_out == NO_PIPE &&
(temp = get_string_value ("auto_resume")))
{
int job, jflags, started_status;
jflags = JM_STOPPED|JM_FIRSTMATCH;
if (STREQ (temp, "exact"))
jflags |= JM_EXACT;
else if (STREQ (temp, "substring"))
jflags |= JM_SUBSTRING;
else
jflags |= JM_PREFIX;
job = get_job_by_name (words->word->word, jflags);
if (job != NO_JOB)
{
run_unwind_frame ("simple-command");
this_command_name = "fg";
last_shell_builtin = this_shell_builtin;
this_shell_builtin = builtin_address ("fg");
started_status = start_job (job, 1);
return ((started_status < 0) ? EXECUTION_FAILURE : started_status);
}
}
#endif /* JOB_CONTROL */
/* unwind-protect this since we will call dispose_words on words if we run
the unwind-protects. */
unwind_protect_string (this_command_name);
run_builtin:
/* Remember the name of this command globally. */
this_command_name = words->word->word;
QUIT;
/* This command could be a shell builtin or a user-defined function.
We have already found special builtins by this time, so we do not
set builtin_is_special. If this is a function or builtin, and we
have pipes, then fork a subshell in here. Otherwise, just execute
the command directly. */
if (func == 0 && builtin == 0)
builtin = find_shell_builtin (this_command_name);
last_shell_builtin = this_shell_builtin;
this_shell_builtin = builtin;
if (builtin || func)
{
if (builtin)
{
old_builtin = executing_builtin;
unwind_protect_int (executing_builtin); /* modified in execute_builtin */
if (old_command_builtin == -1) /* sentinel, can be set above */
{
old_command_builtin = executing_command_builtin;
unwind_protect_int (executing_command_builtin); /* ditto and set above */
}
}
if (already_forked)
{
reset_terminating_signals (); /* XXX */
/* Reset the signal handlers in the child, but don't free the
trap strings. Set a flag noting that we have to free the
trap strings if we run trap to change a signal disposition. */
reset_signal_handlers ();
subshell_environment |= SUBSHELL_RESETTRAP;
subshell_environment &= ~SUBSHELL_IGNTRAP;
if (async)
{
if ((cmdflags & CMD_STDIN_REDIR) &&
pipe_in == NO_PIPE &&
(stdin_redirects (simple_command->redirects) == 0))
async_redirect_stdin ();
setup_async_signals ();
}
if (async == 0) /* XXX why async == 0? */
subshell_level++;
execute_subshell_builtin_or_function
(words, simple_command->redirects, builtin, func,
pipe_in, pipe_out, async, fds_to_close,
cmdflags);
subshell_level--;
}
else
{
result = execute_builtin_or_function
(words, builtin, func, simple_command->redirects, fds_to_close,
cmdflags);
if (builtin)
{
if (result > EX_SHERRBASE)
{
switch (result)
{
case EX_REDIRFAIL:
case EX_BADASSIGN:
case EX_EXPFAIL:
/* These errors cause non-interactive posix mode shells to exit */
if (posixly_correct && builtin_is_special && interactive_shell == 0)
{
last_command_exit_value = EXECUTION_FAILURE;
jump_to_top_level (ERREXIT);
}
break;
case EX_DISKFALLBACK:
/* XXX - experimental */
executing_builtin = old_builtin;
executing_command_builtin = old_command_builtin;
builtin = 0;
/* The redirections have already been `undone', so this
will have to do them again. But piping is forever. */
pipe_in = pipe_out = -1;
goto execute_from_filesystem;
}
result = builtin_status (result);
if (builtin_is_special)
special_builtin_failed = 1; /* XXX - take command builtin into account? */
}
/* In POSIX mode, if there are assignment statements preceding
a special builtin, they persist after the builtin
completes. */
if (posixly_correct && builtin_is_special && temporary_env)
merge_temporary_env ();
}
else /* function */
{
if (result == EX_USAGE)
result = EX_BADUSAGE;
else if (result > EX_SHERRBASE)
result = builtin_status (result);
}
set_pipestatus_from_exit (result);
goto return_result;
}
}
if (autocd && interactive && words->word && is_dirname (words->word->word))
{
words = make_word_list (make_word ("--"), words);
words = make_word_list (make_word ("cd"), words);
xtrace_print_word_list (words, 0);
func = find_function ("cd");
goto run_builtin;
}
execute_from_filesystem:
if (command_line == 0)
command_line = savestring (the_printed_command_except_trap ? the_printed_command_except_trap : "");
#if defined (PROCESS_SUBSTITUTION)
/* The old code did not test already_forked and only did this if
subshell_environment&SUBSHELL_COMSUB != 0 (comsubs and procsubs). Other
uses of the no-fork optimization left FIFOs in $TMPDIR */
if (already_forked == 0 && (cmdflags & CMD_NO_FORK) && fifos_pending () > 0)
cmdflags &= ~CMD_NO_FORK;
if (dofork && already_forked && (subshell_environment & SUBSHELL_PIPE) &&
(cmdflags & CMD_NO_FORK) && fifos_pending () > 0)
#if 0
cmdflags &= ~CMD_NO_FORK;
#else
; /* can't turn off nofork here, too many processes have the FIFOs open */
#endif
#endif
result = execute_disk_command (words, simple_command->redirects, command_line,
pipe_in, pipe_out, async, fds_to_close,
cmdflags);
return_result:
bind_lastarg (lastarg);
FREE (command_line);
dispose_words (words);
if (builtin)
{
executing_builtin = old_builtin;
executing_command_builtin = old_command_builtin;
}
discard_unwind_frame ("simple-command");
this_command_name = (char *)NULL; /* points to freed memory now */
return (result);
}
/* Translate the special builtin exit statuses. We don't really need a
function for this; it's a placeholder for future work. */
static int
builtin_status (int result)
{
int r;
switch (result)
{
case EX_USAGE:
case EX_BADSYNTAX:
r = EX_BADUSAGE;
break;
case EX_REDIRFAIL:
case EX_BADASSIGN:
case EX_EXPFAIL:
case EX_UTILERROR:
r = EXECUTION_FAILURE;
break;
default:
/* other special exit statuses not yet defined */
r = (result > EX_SHERRBASE) ? EXECUTION_FAILURE : EXECUTION_SUCCESS;
break;
}
return (r);
}
static int
execute_builtin (sh_builtin_func_t *builtin, WORD_LIST *words, int flags, int subshell)
{
int result, eval_unwind, ignexit_flag;
int isbltinenv, should_keep;
char *error_trap;
error_trap = 0;
should_keep = 0;
/* The eval builtin calls parse_and_execute, which does not know about
the setting of flags, and always calls the execution functions with
flags that will exit the shell on an error if -e is set. If the
eval builtin is being called, and we're supposed to ignore the exit
value of the command, we turn the -e flag off ourselves and disable
the ERR trap, then restore them when the command completes. This is
also a problem (as below) for the command and source/. builtins. */
if (subshell == 0 && (flags & CMD_IGNORE_RETURN) &&
(builtin == eval_builtin || (flags & CMD_COMMAND_BUILTIN) || builtin == source_builtin))
{
begin_unwind_frame ("eval_builtin");
unwind_protect_int (exit_immediately_on_error);
unwind_protect_int (builtin_ignoring_errexit);
error_trap = TRAP_STRING (ERROR_TRAP);
if (error_trap)
{
error_trap = savestring (error_trap);
add_unwind_protect (xfree, error_trap);
add_unwind_protect (uw_set_error_trap, error_trap);
restore_default_signal (ERROR_TRAP);
}
exit_immediately_on_error = 0;
ignexit_flag = builtin_ignoring_errexit;
builtin_ignoring_errexit = 1;
eval_unwind = 1;
}
else
eval_unwind = 0;
/* The temporary environment for a builtin is supposed to apply to
all commands executed by that builtin. Currently, this is a
problem only with the `unset', `source' and `eval' builtins.
`mapfile' is a special case because it uses evalstring (same as
eval or source) to run its callbacks. */
/* SHOULD_KEEP is for the pop_scope call below; it only matters when
posixly_correct is set, but we should propagate the temporary environment
to the enclosing environment only for special builtins. */
isbltinenv = (builtin == source_builtin || builtin == eval_builtin || builtin == unset_builtin || builtin == mapfile_builtin);
should_keep = isbltinenv && builtin != mapfile_builtin;
#if defined (HISTORY) && defined (READLINE)
if (builtin == fc_builtin || builtin == read_builtin)
{
isbltinenv = 1;
should_keep = 0;
}
#endif
if (isbltinenv)
{
if (subshell == 0)
begin_unwind_frame ("builtin_env");
if (temporary_env)
{
push_scope (VC_BLTNENV, temporary_env);
if (flags & CMD_COMMAND_BUILTIN)
should_keep = 0;
if (subshell == 0)
add_unwind_protect (pop_scope, (void *) (intptr_t) should_keep);
temporary_env = (HASH_TABLE *)NULL;
}
}
if (subshell == 0 && builtin == eval_builtin)
{
if (evalnest_max > 0 && evalnest >= evalnest_max)
{
internal_error (_("eval: maximum eval nesting level exceeded (%d)"), evalnest);
run_unwind_protects (); /* XXX */
evalnest = 0;
jump_to_top_level (DISCARD); /* XXX - cleanup? */
}
unwind_protect_int (evalnest);
/* The test for subshell == 0 above doesn't make a difference */
evalnest++; /* execute_subshell_builtin_or_function sets this to 0 */
}
else if (subshell == 0 && builtin == source_builtin)
{
if (sourcenest_max > 0 && sourcenest >= sourcenest_max)
{
internal_error (_("%s: maximum source nesting level exceeded (%d)"), this_command_name, sourcenest);
run_unwind_protects (); /* XXX */
sourcenest = 0;
jump_to_top_level (DISCARD); /* XXX - cleanup? */
}
unwind_protect_int (sourcenest);
/* The test for subshell == 0 above doesn't make a difference */
sourcenest++; /* execute_subshell_builtin_or_function sets this to 0 */
}
/* `return' does a longjmp() back to a saved environment in execute_function.
If a variable assignment list preceded the command, and the shell is
running in POSIX mode, we need to merge that into the shell_variables
table, since `return' is a POSIX special builtin. We don't do this if
it's being run by the `command' builtin, since that's supposed to inhibit
the special builtin properties. */
if (posixly_correct && subshell == 0 && builtin == return_builtin && (flags & CMD_COMMAND_BUILTIN) == 0 && temporary_env)
{
begin_unwind_frame ("return_temp_env");
add_unwind_protect (uw_merge_temporary_env, NULL);
}
executing_builtin++;
executing_command_builtin |= builtin == command_builtin;
result = ((*builtin) (words->next));
/* This shouldn't happen, but in case `return' comes back instead of
longjmp'ing, we need to unwind. */
if (posixly_correct && subshell == 0 && builtin == return_builtin && temporary_env)
discard_unwind_frame ("return_temp_env");
if (subshell == 0 && isbltinenv)
run_unwind_frame ("builtin_env");
if (eval_unwind)
{
builtin_ignoring_errexit = ignexit_flag;
exit_immediately_on_error = builtin_ignoring_errexit ? 0 : errexit_flag;
if (error_trap)
{
set_error_trap (error_trap);
free (error_trap);
}
discard_unwind_frame ("eval_builtin");
}
return (result);
}
void
uw_maybe_restore_getopt_state (void *arg)
{
sh_getopt_state_t *gs;
gs = arg;
/* If we have a local copy of OPTIND and it's at the right (current)
context, then we restore getopt's internal state. If not, we just
let it go. We know there is a local OPTIND if gs->gs_flags & 1.
This is set below in execute_function() before the context is run. */
if (gs->gs_flags & 1)
sh_getopt_restore_istate (gs);
else
free (gs);
}
#if defined (ARRAY_VARS)
void
restore_funcarray_state (struct func_array_state *fa)
{
SHELL_VAR *nfv;
ARRAY *funcname_a;
array_pop (fa->source_a);
array_pop (fa->lineno_a);
GET_ARRAY_FROM_VAR ("FUNCNAME", nfv, funcname_a);
if (nfv == fa->funcname_v)
array_pop (funcname_a);
free (fa);
}
void
uw_restore_funcarray_state (void *fa)
{
restore_funcarray_state (fa);
}
#endif
static void
function_misc_cleanup (void)
{
if (variable_context == 0 || this_shell_function == 0)
{
make_funcname_visible (0);
#if defined (PROCESS_SUBSTITUTION)
unlink_fifo_list ();
#endif
}
}
static void
uw_function_misc_cleanup (void *ignore)
{
function_misc_cleanup ();
}
static int
execute_function (SHELL_VAR *var, WORD_LIST *words, int flags, struct fd_bitmap *fds_to_close, int async, int subshell)
{
int return_val, result, lineno;
COMMAND *tc, *fc, *save_current;
char *debug_trap, *error_trap, *return_trap;
#if defined (ARRAY_VARS)
SHELL_VAR *funcname_v, *bash_source_v, *bash_lineno_v;
ARRAY *funcname_a;
volatile ARRAY *bash_source_a;
volatile ARRAY *bash_lineno_a;
struct func_array_state *fa;
#endif
FUNCTION_DEF *shell_fn;
char *sfile, *t;
sh_getopt_state_t *gs;
SHELL_VAR *gv;
USE_VAR(fc);
if (funcnest_max > 0 && funcnest >= funcnest_max)
{
internal_error (_("%s: maximum function nesting level exceeded (%d)"), var->name, funcnest);
run_unwind_protects (); /* XXX */
funcnest = 0; /* XXX - should we reset it somewhere else? */
jump_to_top_level (DISCARD);
}
#if defined (ARRAY_VARS)
GET_ARRAY_FROM_VAR ("FUNCNAME", funcname_v, funcname_a);
GET_ARRAY_FROM_VAR ("BASH_SOURCE", bash_source_v, bash_source_a);
GET_ARRAY_FROM_VAR ("BASH_LINENO", bash_lineno_v, bash_lineno_a);
#endif
tc = (COMMAND *)copy_command (function_cell (var));
if (tc && (flags & CMD_IGNORE_RETURN))
tc->flags |= CMD_IGNORE_RETURN;
/* A limited attempt at optimization: shell functions at the end of command
substitutions that are already marked NO_FORK. */
if (tc && (flags & CMD_NO_FORK) && (subshell_environment & SUBSHELL_COMSUB))
optimize_shell_function (tc);
gs = sh_getopt_save_istate ();
if (subshell == 0)
{
begin_unwind_frame ("function_calling");
/* If the shell is in posix mode, this will push the variables in
the temporary environment to the "current shell environment" (the
global scope), and dispose the temporary env before setting it to
NULL later. This behavior has disappeared from the latest edition
of the standard, so I will eventually remove it from variables.c:
push_var_context. */
push_context (var->name, subshell, temporary_env);
/* This has to be before the pop_context(), because the unwinding of
local variables may cause the restore of a local declaration of
OPTIND to force a getopts state reset. */
add_unwind_protect (uw_maybe_restore_getopt_state, gs);
/* This also, because pop_context has to decrement variable_context */
add_unwind_protect (uw_function_misc_cleanup, NULL);
add_unwind_protect (pop_context, NULL);
unwind_protect_int (line_number);
unwind_protect_int (line_number_for_err_trap);
unwind_protect_int (function_line_number);
unwind_protect_int (return_catch_flag);
unwind_protect_jmp_buf (return_catch);
add_unwind_protect (uw_dispose_command, (char *)tc);
unwind_protect_pointer (this_shell_function);
unwind_protect_int (funcnest);
unwind_protect_int (loop_level);
}
else
push_context (var->name, subshell, temporary_env); /* don't unwind-protect for subshells */
temporary_env = (HASH_TABLE *)NULL;
this_shell_function = var;
make_funcname_visible (1);
debug_trap = TRAP_STRING(DEBUG_TRAP);
error_trap = TRAP_STRING(ERROR_TRAP);
return_trap = TRAP_STRING(RETURN_TRAP);
/* The order of the unwind protects for debug_trap, error_trap and
return_trap is important here! unwind-protect commands are run
in reverse order of registration. If this causes problems, take
out the xfree unwind-protect calls and live with the small memory leak. */
/* function_trace_mode != 0 means that all functions inherit the DEBUG trap.
if the function has the trace attribute set, it inherits the DEBUG trap */
if (debug_trap && ((trace_p (var) == 0) && function_trace_mode == 0))
{
if (subshell == 0)
{
debug_trap = savestring (debug_trap);
add_unwind_protect (xfree, debug_trap);
add_unwind_protect (uw_maybe_set_debug_trap, debug_trap);
}
restore_default_signal (DEBUG_TRAP);
}
/* error_trace_mode != 0 means that functions inherit the ERR trap. */
if (error_trap && error_trace_mode == 0)
{
if (subshell == 0)
{
error_trap = savestring (error_trap);
add_unwind_protect (xfree, error_trap);
add_unwind_protect (uw_maybe_set_error_trap, error_trap);
}
restore_default_signal (ERROR_TRAP);
}
/* Shell functions inherit the RETURN trap if function tracing is on
globally or on individually for this function. */
if (return_trap && (signal_in_progress (DEBUG_TRAP) || ((trace_p (var) == 0) && function_trace_mode == 0)))
{
if (subshell == 0)
{
return_trap = savestring (return_trap);
add_unwind_protect (xfree, return_trap);
add_unwind_protect (uw_maybe_set_return_trap, return_trap);
}
restore_default_signal (RETURN_TRAP);
}
funcnest++;
#if defined (ARRAY_VARS)
/* This is quite similar to the code in shell.c and elsewhere. */
shell_fn = find_function_def (this_shell_function->name);
sfile = shell_fn ? shell_fn->source_file : "";
array_push ((ARRAY *)funcname_a, this_shell_function->name);
push_source ((ARRAY *)bash_source_a, sfile);
lineno = GET_LINE_NUMBER ();
t = itos (lineno);
array_push ((ARRAY *)bash_lineno_a, t);
free (t);
#endif
#if defined (ARRAY_VARS)
fa = (struct func_array_state *)xmalloc (sizeof (struct func_array_state));
fa->source_a = (ARRAY *)bash_source_a;
fa->source_v = bash_source_v;
fa->lineno_a = (ARRAY *)bash_lineno_a;
fa->lineno_v = bash_lineno_v;
fa->funcname_a = (ARRAY *)funcname_a;
fa->funcname_v = funcname_v;
if (subshell == 0)
add_unwind_protect (uw_restore_funcarray_state, fa);
#endif
/* The temporary environment for a function is supposed to apply to
all commands executed within the function body. */
/* Initialize BASH_ARGC and BASH_ARGV before we blow away the positional
parameters */
if (debugging_mode || shell_compatibility_level <= 44)
init_bash_argv ();
remember_args (words->next, 1);
/* Update BASH_ARGV and BASH_ARGC */
if (debugging_mode)
{
push_args (words->next);
if (subshell == 0)
add_unwind_protect (uw_pop_args, 0);
}
/* Number of the line on which the function body starts. */
line_number = function_line_number = tc->line;
#if defined (JOB_CONTROL)
if (subshell)
stop_pipeline (async, (COMMAND *)NULL);
#endif
if (shell_compatibility_level > 43)
loop_level = 0;
/* unwind-protect this because execute_command_internal will overwrite it
with something we will free if unwind-protects are run */
if (subshell == 0)
unwind_protect_pointer (currently_executing_command);
fc = tc;
from_return_trap = 0;
return_catch_flag++;
return_val = setjmp_nosigs (return_catch);
if (return_val)
{
result = return_catch_value;
/* Run the RETURN trap in the function's context. */
save_current = currently_executing_command;
if (from_return_trap == 0)
run_return_trap ();
currently_executing_command = save_current;
}
else
{
/* Run the debug trap here so we can trap at the start of a function's
execution rather than the execution of the body's first command. */
showing_function_line = 1;
save_current = currently_executing_command;
result = run_debug_trap ();
#if defined (DEBUGGER)
/* In debugging mode, if the DEBUG trap returns a non-zero status, we
skip the command. */
if (debugging_mode == 0 || result == EXECUTION_SUCCESS)
{
showing_function_line = 0;
currently_executing_command = save_current;
result = execute_command_internal (fc, 0, NO_PIPE, NO_PIPE, fds_to_close);
/* Run the RETURN trap in the function's context */
save_current = currently_executing_command;
run_return_trap ();
currently_executing_command = save_current;
}
#else
currently_executing_command = save_current;
result = execute_command_internal (fc, 0, NO_PIPE, NO_PIPE, fds_to_close);
save_current = currently_executing_command;
run_return_trap ();
currently_executing_command = save_current;
#endif
showing_function_line = 0;
}
/* If we have a local copy of OPTIND, note it in the saved getopts state. */
gv = find_variable ("OPTIND");
if (gv && gv->context == variable_context)
gs->gs_flags |= 1;
if (subshell == 0)
run_unwind_frame ("function_calling");
#if defined (ARRAY_VARS)
else
{
restore_funcarray_state (fa);
/* Restore BASH_ARGC and BASH_ARGV */
if (debugging_mode)
pop_args ();
}
#endif
function_misc_cleanup ();
return (result);
}
/* A convenience routine for use by other parts of the shell to execute
a particular shell function. */
int
execute_shell_function (SHELL_VAR *var, WORD_LIST *words)
{
int ret;
struct fd_bitmap *bitmap;
bitmap = new_fd_bitmap (FD_BITMAP_DEFAULT_SIZE);
begin_unwind_frame ("execute-shell-function");
add_unwind_protect (uw_dispose_fd_bitmap, (char *)bitmap);
ret = execute_function (var, words, 0, bitmap, 0, 0);
dispose_fd_bitmap (bitmap);
discard_unwind_frame ("execute-shell-function");
return ret;
}
/* Execute a shell builtin or function in a subshell environment. This
routine does not return; it only calls exit(). If BUILTIN is non-null,
it points to a function to call to execute a shell builtin; otherwise
VAR points at the body of a function to execute. WORDS is the arguments
to the command, REDIRECTS specifies redirections to perform before the
command is executed. */
static void
execute_subshell_builtin_or_function (WORD_LIST *words, REDIRECT *redirects,
sh_builtin_func_t *builtin, SHELL_VAR *var,
int pipe_in, int pipe_out, int async,
struct fd_bitmap *fds_to_close, int flags)
{
int result, r, funcvalue;
#if defined (JOB_CONTROL)
int jobs_hack;
jobs_hack = (builtin == jobs_builtin) &&
((subshell_environment & SUBSHELL_ASYNC) == 0 || pipe_out != NO_PIPE);
#endif
/* A subshell is neither a login shell nor interactive. */
login_shell = interactive = 0;
if (builtin == eval_builtin)
evalnest = 0;
else if (builtin == source_builtin)
sourcenest = 0;
if (async)
subshell_environment |= SUBSHELL_ASYNC;
if (pipe_in != NO_PIPE || pipe_out != NO_PIPE)
subshell_environment |= SUBSHELL_PIPE;
maybe_make_export_env (); /* XXX - is this needed? */
#if defined (JOB_CONTROL)
/* Eradicate all traces of job control after we fork the subshell, so
all jobs begun by this subshell are in the same process group as
the shell itself. */
/* Allow the output of `jobs' to be piped. */
if (jobs_hack)
kill_current_pipeline ();
else
without_job_control ();
set_sigchld_handler ();
#else
without_job_control ();
#endif /* JOB_CONTROL */
/* We don't call set_sigint_handler if async is 1 so we don't undo the work
done by setup_async_signals() in the caller. This is similar to what
execute_in_subshell() does. */
if (async == 0)
{
SigHandler *handler;
handler = set_sigint_handler ();
if (handler == SIG_IGN && signal_is_async_ignored (SIGINT) &&
signal_is_trapped (SIGINT) == 0 && signal_is_hard_ignored (SIGINT) == 0)
set_signal_handler (SIGINT, SIG_IGN);
}
if (fds_to_close)
close_fd_bitmap (fds_to_close);
do_piping (pipe_in, pipe_out);
if (do_redirections (redirects, RX_ACTIVE) != 0)
exit (EXECUTION_FAILURE);
if (builtin)
{
/* Give builtins a place to jump back to on failure,
so we don't go back up to main(). */
result = setjmp_nosigs (top_level);
/* Give the return builtin a place to jump to when executed in a subshell
or pipeline */
funcvalue = 0;
if (return_catch_flag && builtin == return_builtin)
funcvalue = setjmp_nosigs (return_catch);
if (result == EXITPROG || result == EXITBLTIN)
subshell_exit (last_command_exit_value);
#if 0 /* TAG:bash-5.4 https://savannah.gnu.org/support/?109840 6/5/2025 */
else if (result == ERREXIT)
subshell_exit (last_command_exit_value ? last_command_exit_value : EXECUTION_FAILURE);
#endif
else if (result)
subshell_exit (EXECUTION_FAILURE);
else if (funcvalue)
subshell_exit (return_catch_value);
else
{
r = execute_builtin (builtin, words, flags, 1);
fflush (stdout);
if (r == EX_USAGE)
r = EX_BADUSAGE;
/* XXX - experimental */
else if (r == EX_DISKFALLBACK)
{
char *command_line;
command_line = savestring (the_printed_command_except_trap ? the_printed_command_except_trap : "");
r = execute_disk_command (words, (REDIRECT *)0, command_line,
-1, -1, async, (struct fd_bitmap *)0, flags|CMD_NO_FORK);
}
subshell_exit (r);
}
}
else
{
if (async)
optimize_shell_function (function_cell (var));
r = execute_function (var, words, flags, fds_to_close, async, 1);
fflush (stdout);
subshell_exit (r);
}
}
/* Execute a builtin or function in the current shell context. If BUILTIN
is non-null, it is the builtin command to execute, otherwise VAR points
to the body of a function. WORDS are the command's arguments, REDIRECTS
are the redirections to perform. FDS_TO_CLOSE is the usual bitmap of
file descriptors to close.
If BUILTIN is exec_builtin, the redirections specified in REDIRECTS are
not undone before this function returns. */
static int
execute_builtin_or_function (WORD_LIST *words,
sh_builtin_func_t *builtin, SHELL_VAR *var,
REDIRECT *redirects, struct fd_bitmap *fds_to_close,
int flags)
{
int result, has_exec_redirects;
REDIRECT *saved_undo_list;
#if defined (PROCESS_SUBSTITUTION)
int ofifo, nfifo, osize;
void *ofifo_list;
#endif
#if defined (PROCESS_SUBSTITUTION)
begin_unwind_frame ("saved_fifos");
/* If we return, we longjmp and don't get a chance to restore the old
fifo list, so we add an unwind protect to free it */
ofifo = num_fifos ();
ofifo_list = copy_fifo_list (&osize);
if (ofifo_list)
add_unwind_protect (xfree, ofifo_list);
#endif
if (do_redirections (redirects, RX_ACTIVE|RX_UNDOABLE) != 0)
{
undo_partial_redirects ();
dispose_exec_redirects ();
#if defined (PROCESS_SUBSTITUTION)
free (ofifo_list);
#endif
return (EX_REDIRFAIL); /* was EXECUTION_FAILURE */
}
/* Is this the exec builtin with redirections? We want to undo them and
throw away the exec_redirection_undo_list if exec has a program name
argument, fails to execute it, and does not exit the shell */
has_exec_redirects = (builtin == exec_builtin) && redirection_undo_list;
saved_undo_list = redirection_undo_list;
/* Calling the "exec" builtin changes redirections forever. */
if (builtin == exec_builtin)
{
/* let exec_builtin handle disposing redirection_undo_list */
saved_undo_list = exec_redirection_undo_list;
exec_redirection_undo_list = (REDIRECT *)NULL;
}
else
{
dispose_exec_redirects ();
redirection_undo_list = (REDIRECT *)NULL;
}
if (saved_undo_list)
{
begin_unwind_frame ("saved-redirects");
add_unwind_protect (uw_cleanup_redirects, (char *)saved_undo_list);
}
if (builtin)
result = execute_builtin (builtin, words, flags, 0);
else
result = execute_function (var, words, flags, fds_to_close, 0, 0);
/* We do this before undoing the effects of any redirections. */
fflush (stdout);
fpurge (stdout);
if (ferror (stdout))
clearerr (stdout);
if (has_exec_redirects && redirection_undo_list)
{
/* We have returned from the exec builtin. If redirection_undo_list is
still non-null, we had an operand and failed to exit the shell for
some reason. We want to dispose of saved_undo_list, discard the frame,
and let the redirections be undone as usual. If redirection_undo_list
is NULL, then exec_builtin had no program name operand and disposed
of it. In that case, we should perform the redirections in
exec_redirection_undo_list (saved_undo_list) like usual. */
if (saved_undo_list)
{
dispose_redirects (saved_undo_list); /* exec_redirection_undo_list */
discard_unwind_frame ("saved-redirects");
}
saved_undo_list = exec_redirection_undo_list = (REDIRECT *)NULL;
}
/* This code is no longer executed and remains only for explanatory reasons. */
else if (builtin == command_builtin && this_shell_builtin == exec_builtin)
{
/* If we are executing the `command' builtin, but this_shell_builtin is
set to `exec_builtin', we know that we have something like
`command exec [redirection]', since otherwise `exec' would have
overwritten the shell and we wouldn't get here. In this case, we
want to behave as if the `command' builtin had not been specified
and preserve the redirections. */
if (saved_undo_list)
{
dispose_redirects (saved_undo_list); /* redirection_undo_list */
discard_unwind_frame ("saved-redirects");
}
redirection_undo_list = exec_redirection_undo_list;
saved_undo_list = exec_redirection_undo_list = (REDIRECT *)NULL;
}
if (saved_undo_list)
{
redirection_undo_list = saved_undo_list;
discard_unwind_frame ("saved-redirects");
}
undo_partial_redirects ();
#if defined (PROCESS_SUBSTITUTION)
/* Close any FIFOs created by this builtin or function. */
nfifo = num_fifos ();
if (nfifo > ofifo)
close_new_fifos (ofifo_list, osize);
if (ofifo_list)
free (ofifo_list);
discard_unwind_frame ("saved_fifos");
#endif
return (result);
}
void
setup_async_signals (void)
{
#if defined (__BEOS__)
set_signal_handler (SIGHUP, SIG_IGN); /* they want csh-like behavior */
#endif
if (job_control == 0)
{
/* Make sure we get the original signal dispositions now so we don't
confuse the trap builtin later if the subshell tries to use it to
reset SIGINT/SIGQUIT. Don't call set_signal_ignored; we use
set_signal_async_ignored to set the value of original_signals to
SIG_IGN and set additional flags to satisfy Posix interpretation 751. */
get_original_signal (SIGINT);
set_signal_handler (SIGINT, SIG_IGN);
/* We use set_signal_async_ignored here to make sure that restore_signal
doesn't undo this work. We want processes that are created by this
asynchronous subshell to ignore SIGINT as well. We can't set the
hard ignored flag because that would prevent the trap builtin from
setting a trap. We also have to special-case set_signal so we can
set a trap for one of these signals. */
set_signal_async_ignored (SIGINT);
get_original_signal (SIGQUIT);
set_signal_handler (SIGQUIT, SIG_IGN);
set_signal_async_ignored (SIGQUIT);
}
}
/* Execute a simple command that is hopefully defined in a disk file
somewhere.
1) fork ()
2) connect pipes
3) look up the command
4) do redirections
5) execve ()
6) If the execve failed, see if the file has executable mode set.
If so, and it isn't a directory, then execute its contents as
a shell script.
Note that the filename hashing stuff has to take place up here,
in the parent. This is probably why the Bourne style shells
don't handle it, since that would require them to go through
this gnarly hair, for no good reason.
NOTE: callers expect this to fork or exit(). */
/* See comment above where notfound_str is declared. */
void
init_notfound_str (void)
{
if (notfound_str == 0)
notfound_str = _("command not found");
}
/* Name of a shell function to call when a command name is not found. */
#ifndef NOTFOUND_HOOK
# define NOTFOUND_HOOK "command_not_found_handle"
#endif
static int
execute_disk_command (WORD_LIST *words, REDIRECT *redirects, char *command_line,
int pipe_in, int pipe_out, int async,
struct fd_bitmap *fds_to_close, int cmdflags)
{
char *pathname, *command, **args, *p;
int nofork, stdpath, result, fork_flags;
pid_t pid;
SHELL_VAR *hookf;
WORD_LIST *wl;
stdpath = (cmdflags & CMD_STDPATH); /* use command -p path */
nofork = (cmdflags & CMD_NO_FORK); /* Don't fork, just exec, if no pipes */
pathname = words->word->word;
p = 0;
result = EXECUTION_SUCCESS;
#if defined (RESTRICTED_SHELL)
command = (char *)NULL;
if (restricted && mbschr (pathname, '/'))
{
internal_error (_("%s: restricted: cannot specify `/' in command names"),
pathname);
result = last_command_exit_value = EXECUTION_FAILURE;
/* If we're not going to fork below, we must already be in a child
process or a context in which it's safe to call exit(2). */
if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE)
exit (last_command_exit_value);
else
goto parent_return;
}
#endif /* RESTRICTED_SHELL */
/* If we want to change this so `command -p' (CMD_STDPATH) does not insert
any pathname it finds into the hash table, it should read
command = search_for_command (pathname, stdpath ? CMDSRCH_STDPATH : CMDSRCH_HASH);
*/
command = search_for_command (pathname, CMDSRCH_HASH|(stdpath ? CMDSRCH_STDPATH : 0));
QUIT;
if (command)
{
/* If we're optimizing out the fork (implicit `exec'), decrement the
shell level like `exec' would do. Don't do this if we are already
in a pipeline environment, assuming it's already been done. */
if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE && (subshell_environment & SUBSHELL_PIPE) == 0)
adjust_shell_level (-1);
maybe_make_export_env ();
put_command_name_into_env (command);
}
else if (command == 0 && notfound_str == 0) /* make sure */
init_notfound_str ();
/* We have to make the child before we check for the non-existence
of COMMAND, since we want the error messages to be redirected. */
/* If we can get away without forking and there are no pipes to deal with,
don't bother to fork, just directly exec the command. */
if (nofork && pipe_in == NO_PIPE && pipe_out == NO_PIPE)
pid = 0;
else
{
fork_flags = async ? FORK_ASYNC : 0;
pid = make_child (p = savestring (command_line), fork_flags);
}
if (pid == 0)
{
int old_interactive;
reset_terminating_signals (); /* XXX */
/* Cancel traps, in trap.c. */
restore_original_signals ();
subshell_environment &= ~SUBSHELL_IGNTRAP;
#if defined (JOB_CONTROL)
FREE (p);
#endif
/* restore_original_signals may have undone the work done
by make_child to ensure that SIGINT and SIGQUIT are ignored
in asynchronous children. */
if (async)
{
if ((cmdflags & CMD_STDIN_REDIR) &&
pipe_in == NO_PIPE &&
(stdin_redirects (redirects) == 0))
async_redirect_stdin ();
setup_async_signals ();
}
/* This functionality is now provided by close-on-exec of the
file descriptors manipulated by redirection and piping.
Some file descriptors still need to be closed in all children
because of the way bash does pipes; fds_to_close is a
bitmap of all such file descriptors. */
if (fds_to_close)
close_fd_bitmap (fds_to_close);
do_piping (pipe_in, pipe_out);
old_interactive = interactive;
if (async)
interactive = 0;
subshell_environment |= SUBSHELL_FORK; /* XXX - was just = */
#if defined (PROCESS_SUBSTITUTION) && !defined (HAVE_DEV_FD)
clear_fifo_list (); /* XXX - we haven't created any FIFOs */
#endif
/* reset shell_pgrp to pipeline_pgrp here for word expansions performed
by the redirections here? */
if (redirects && (do_redirections (redirects, RX_ACTIVE) != 0))
{
#if defined (PROCESS_SUBSTITUTION)
/* Try to remove named pipes that may have been created as the
result of redirections. */
unlink_all_fifos ();
#endif /* PROCESS_SUBSTITUTION */
exit (EXECUTION_FAILURE);
}
#if defined (PROCESS_SUBSTITUTION) && !defined (HAVE_DEV_FD)
/* This should only contain FIFOs created as part of redirection
expansion. */
unlink_all_fifos ();
#endif
if (async)
interactive = old_interactive;
if (command == 0)
{
hookf = find_function (NOTFOUND_HOOK);
if (hookf == 0)
{
/* Make sure filenames are displayed using printable characters */
pathname = printable_filename (pathname, 0);
internal_error ("%s: %s", pathname, notfound_str);
exit (EX_NOTFOUND); /* Posix.2 says the exit status is 127 */
}
/* We don't want to manage process groups for processes we start
from here, so we turn off job control and don't attempt to
manipulate the terminal's process group. */
without_job_control ();
#if defined (JOB_CONTROL)
set_sigchld_handler ();
#endif
wl = make_word_list (make_word (NOTFOUND_HOOK), words);
exit (execute_shell_function (hookf, wl));
}
/* Execve expects the command name to be in args[0]. So we
leave it there, in the same format that the user used to
type it in. */
args = strvec_from_word_list (words, 0, 0, (int *)NULL);
exit (shell_execve (command, args, export_env));
}
else
{
parent_return:
QUIT;
/* Make sure that the pipes are closed in the parent. */
close_pipes (pipe_in, pipe_out);
#if 0
#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
if (variable_context == 0)
unlink_fifo_list ();
#endif
#endif
FREE (command);
return (result);
}
}
/* CPP defines to decide whether a particular index into the #! line
corresponds to a valid interpreter name or argument character, or
whitespace. The MSDOS define is to allow \r to be treated the same
as \n. */
#if !defined (MSDOS)
# define STRINGCHAR(ind) \
(ind < sample_len && !whitespace (sample[ind]) && sample[ind] != '\n')
# define WHITECHAR(ind) \
(ind < sample_len && whitespace (sample[ind]))
#else /* MSDOS */
# define STRINGCHAR(ind) \
(ind < sample_len && !whitespace (sample[ind]) && sample[ind] != '\n' && sample[ind] != '\r')
# define WHITECHAR(ind) \
(ind < sample_len && whitespace (sample[ind]))
#endif /* MSDOS */
static char *
getinterp (char *sample, int sample_len, int *endp)
{
int i;
char *execname;
int start;
/* Find the name of the interpreter to exec. */
for (i = 2; i < sample_len && whitespace (sample[i]); i++)
;
for (start = i; STRINGCHAR(i); i++)
;
execname = substring (sample, start, i);
if (endp)
*endp = i;
return execname;
}
#if !defined (HAVE_HASH_BANG_EXEC)
/* If the operating system on which we're running does not handle
the #! executable format, then help out. SAMPLE is the text read
from the file, SAMPLE_LEN characters. COMMAND is the name of
the script; it and ARGS, the arguments given by the user, will
become arguments to the specified interpreter. ENV is the environment
to pass to the interpreter.
The word immediately following the #! is the interpreter to execute.
A single argument to the interpreter is allowed. */
static int
execute_shell_script (char *sample, int sample_len,
char *command, char **args, char **env)
{
char *execname, *firstarg;
int i, start, size_increment, larry;
/* Find the name of the interpreter to exec. */
execname = getinterp (sample, sample_len, &i);
size_increment = 1;
/* Now the argument, if any. */
for (firstarg = NULL, start = i; WHITECHAR(i); i++)
;
/* If there is more text on the line, then it is an argument for the
interpreter. */
if (STRINGCHAR(i))
{
for (start = i; STRINGCHAR(i); i++)
;
firstarg = substring ((char *)sample, start, i);
size_increment = 2;
}
larry = strvec_len (args) + size_increment;
args = strvec_resize (args, larry + 1);
for (i = larry - 1; i; i--)
args[i] = args[i - size_increment];
args[0] = execname;
if (firstarg)
{
args[1] = firstarg;
args[2] = command;
}
else
args[1] = command;
args[larry] = (char *)NULL;
return (shell_execve (execname, args, env));
}
#undef STRINGCHAR
#undef WHITECHAR
#endif /* !HAVE_HASH_BANG_EXEC */
static void
initialize_subshell (void)
{
#if defined (ALIAS)
/* Forget about any aliases that we knew of. We are in a subshell. */
delete_all_aliases ();
#endif /* ALIAS */
#if defined (HISTORY)
/* Forget about the history lines we have read. This is a non-interactive
subshell. */
history_lines_this_session = 0;
#endif
/* Forget about the way job control was working. We are in a subshell. */
without_job_control ();
#if defined (JOB_CONTROL)
set_sigchld_handler ();
init_job_stats ();
#endif /* JOB_CONTROL */
/* Reset the values of the shell flags and options. */
reset_shell_flags ();
reset_shell_options ();
reset_shopt_options ();
/* Zero out builtin_env, since this could be a shell script run from a
sourced file with a temporary environment supplied to the `source/.'
builtin. Such variables are not supposed to be exported (empirical
testing with sh and ksh). Just throw it away; don't worry about a
memory leak. */
if (vc_isbltnenv (shell_variables))
shell_variables = shell_variables->down;
clear_unwind_protect_list (0);
/* XXX -- are there other things we should be resetting here? */
parse_and_execute_level = 0; /* nothing left to restore it */
/* We're no longer inside a shell function. */
variable_context = return_catch_flag = funcnest = evalnest = sourcenest = 0;
interrupt_execution = retain_fifos = 0; /* XXX */
executing_funsub = 0; /* XXX */
/* If we're not interactive, close the file descriptor from which we're
reading the current shell script. */
if (interactive_shell == 0)
unset_bash_input (0);
}
#if defined (HAVE_SETOSTYPE) && defined (_POSIX_SOURCE)
# define SETOSTYPE(x) __setostype(x)
#else
# define SETOSTYPE(x)
#endif
#define HASH_BANG_BUFSIZ 128
#define READ_SAMPLE_BUF(file, buf, len) \
do \
{ \
fd = open(file, O_RDONLY); \
if (fd >= 0) \
{ \
len = read (fd, buf, HASH_BANG_BUFSIZ); \
close (fd); \
} \
else \
len = -1; \
} \
while (0)
/* Call execve (), handling interpreting shell scripts, and handling
exec failures. */
int
shell_execve (char *command, char **args, char **env)
{
int i, fd, sample_len;
char sample[HASH_BANG_BUFSIZ];
size_t larray;
SETOSTYPE (0); /* Some systems use for USG/POSIX semantics */
execve (command, args, env);
i = errno; /* error from execve() */
CHECK_TERMSIG;
SETOSTYPE (1);
/* If we get to this point, then start checking out the file.
Maybe it is something we can hack ourselves. */
if (i != ENOEXEC)
{
/* make sure this is set correctly for file_error/report_error */
last_command_exit_value = (i == ENOENT) ? EX_NOTFOUND : EX_NOEXEC; /* XXX Posix.2 says that exit status is 126 */
if (file_isdir (command))
#if defined (EISDIR)
internal_error ("%s: %s", command, strerror (EISDIR));
#else
internal_error (_("%s: is a directory"), command);
#endif
else if (executable_file (command) == 0)
{
errno = i;
file_error (command);
}
/* errors not involving the path argument to execve. */
else if (i == E2BIG || i == ENOMEM)
{
errno = i;
file_error (command);
}
else
{
/* The file has the execute bits set, but the kernel refuses to
run it for some reason. See why. */
#if defined (HAVE_HASH_BANG_EXEC)
READ_SAMPLE_BUF (command, sample, sample_len);
if (sample_len > 0)
sample[sample_len - 1] = '\0';
if (sample_len > 2 && sample[0] == '#' && sample[1] == '!')
{
char *interp;
size_t ilen;
interp = getinterp (sample, sample_len, (int *)NULL);
ilen = strlen (interp);
errno = i;
if (ilen > 0 && interp[ilen - 1] == '\r')
{
interp = xrealloc (interp, ilen + 2);
interp[ilen - 1] = '^';
interp[ilen] = 'M';
interp[ilen + 1] = '\0';
}
sys_error ("%s: %s: %s", command, interp, _("bad interpreter"));
FREE (interp);
return (EX_NOEXEC);
}
else
#endif
if (i == ENOENT)
{
errno = i;
internal_error (_("%s: cannot execute: required file not found"), command);
}
else
{
errno = i;
file_error (command);
}
}
return (last_command_exit_value);
}
/* This file is executable.
If it begins with #!, then help out people with losing operating
systems. Otherwise, check to see if it is a binary file by seeing
if the contents of the first line (or up to 80 characters) are in the
ASCII set. If it's a text file, execute the contents as shell commands,
otherwise return 126 (EX_BINARY_FILE). */
READ_SAMPLE_BUF (command, sample, sample_len);
if (sample_len == 0)
return (EXECUTION_SUCCESS);
/* Is this supposed to be an executable script?
If so, the format of the line is "#! interpreter [argument]".
A single argument is allowed. The BSD kernel restricts
the length of the entire line to 32 characters (32 bytes
being the size of the BSD exec header), but we allow up to 128
characters. */
if (sample_len > 0)
{
#if !defined (HAVE_HASH_BANG_EXEC)
if (sample_len > 2 && sample[0] == '#' && sample[1] == '!')
return (execute_shell_script (sample, sample_len, command, args, env));
else
#endif
if (check_binary_file (sample, sample_len))
{
internal_error ("%s: %s: %s", command, _("cannot execute binary file"), strerror (i));
errno = i;
return (EX_BINARY_FILE);
}
}
/* We have committed to attempting to execute the contents of this file
as shell commands. */
reset_parser ();
initialize_subshell ();
set_sigint_handler ();
/* Insert the name of this shell into the argument list. */
larray = strvec_len (args) + 1;
args = strvec_resize (args, larray + 1);
for (i = larray - 1; i; i--)
args[i] = args[i - 1];
args[0] = shell_name;
args[1] = command;
args[larray] = (char *)NULL;
if (args[0][0] == '-')
args[0]++;
#if defined (RESTRICTED_SHELL)
if (restricted)
change_flag ('r', FLAG_OFF);
#endif
if (subshell_argv)
{
/* Can't free subshell_argv[0]; that is shell_name. */
for (i = 1; i < subshell_argc; i++)
free (subshell_argv[i]);
free (subshell_argv);
}
dispose_command (currently_executing_command); /* XXX */
currently_executing_command = (COMMAND *)NULL;
subshell_argc = larray;
subshell_argv = args;
subshell_envp = env;
unbind_args (); /* remove the positional parameters */
#if defined (PROCESS_SUBSTITUTION) && defined (HAVE_DEV_FD)
clear_fifo_list (); /* pipe fds are what they are now */
#endif
sh_longjmp (subshell_top_level, 1);
/*NOTREACHED*/
}
static int
execute_intern_function (WORD_DESC *name, FUNCTION_DEF *funcdef)
{
SHELL_VAR *var;
char *t;
int pflags;
/* This is where we enforce any restrictions on the function name via the
call to valid_function_word(). */
pflags = 0;
#if POSIX_RESTRICT_FUNCNAME
if (posixly_correct)
pflags |= 1; /* enforce posix function name restrictions */
#endif
if (posixly_correct)
pflags |= 4; /* no special builtins */
/* We still allow functions with the same name as reserved words, so they
can be called if quoted. */
if (valid_function_word (name, pflags) == 0)
{
if (posixly_correct)
{
last_command_exit_value = EX_BADUSAGE;
jump_to_top_level (interactive_shell ? DISCARD : ERREXIT);
}
return (EXECUTION_FAILURE);
}
if (strchr (name->word, CTLESC)) /* WHY? */
{
t = dequote_escapes (name->word);
free (name->word);
name->word = t;
}
var = find_function (name->word);
if (var && ASSIGN_DISALLOWED (var, 0))
{
if (readonly_p (var))
internal_error (_("%s: readonly function"), var->name);
return (EXECUTION_FAILURE);
}
#if defined (DEBUGGER)
bind_function_def (name->word, funcdef, 1);
#endif
bind_function (name->word, funcdef->command);
return (EXECUTION_SUCCESS);
}
#if defined (INCLUDE_UNUSED)
#if defined (PROCESS_SUBSTITUTION)
void
close_all_files (void)
{
int i, fd_table_size;
fd_table_size = getdtablesize ();
if (fd_table_size > 256) /* clamp to a reasonable value */
fd_table_size = 256;
for (i = 3; i < fd_table_size; i++)
close (i);
}
#endif /* PROCESS_SUBSTITUTION */
#endif
static void
close_pipes (int in, int out)
{
if (in >= 0)
close (in);
if (out >= 0)
close (out);
}
static void
dup_error (int oldd, int newd)
{
sys_error (_("cannot duplicate fd %d to fd %d"), oldd, newd);
}
/* Redirect input and output to be from and to the specified pipes.
NO_PIPE and REDIRECT_BOTH are handled correctly. */
static void
do_piping (int pipe_in, int pipe_out)
{
if (pipe_in != NO_PIPE)
{
if (dup2 (pipe_in, 0) < 0)
dup_error (pipe_in, 0);
if (pipe_in > 0)
close (pipe_in);
#ifdef __CYGWIN__
/* Let stdio know the fd may have changed from text to binary mode. */
freopen (NULL, "r", stdin);
#endif /* __CYGWIN__ */
}
if (pipe_out != NO_PIPE)
{
if (pipe_out != REDIRECT_BOTH)
{
if (dup2 (pipe_out, 1) < 0)
dup_error (pipe_out, 1);
if (pipe_out == 0 || pipe_out > 1)
close (pipe_out);
}
else
{
if (dup2 (1, 2) < 0)
dup_error (1, 2);
}
#ifdef __CYGWIN__
/* Let stdio know the fd may have changed from text to binary mode, and
make sure to preserve stdout line buffering. */
freopen (NULL, "w", stdout);
sh_setlinebuf (stdout);
#endif /* __CYGWIN__ */
}
}