This is a terse description of the new features added to readline-6.3 since the release of readline-6.2. New Features in Readline a. Readline is now more responsive to SIGHUP and other fatal signals when reading input from the terminal or performing word completion but no longer attempts to run any not-allowable functions from a signal handler context. b. There are new bindable commands to search the history for the string of characters between the beginning of the line and the point (history-substring-search-forward, history-substring-search-backward) c. Readline allows quoted strings as the values of variables when setting them with `set'. As a side effect, trailing spaces and tabs are ignored when setting a string variable's value. d. The history library creates a backup of the history file when writing it and restores the backup on a write error. e. New application-settable variable: rl_filename_stat_hook: a function called with a filename before using it in a call to stat(2). Bash uses it to expand shell variables so things like $HOME/Downloads have a slash appended. f. New bindable function `print-last-kbd-macro', prints the most-recently- defined keyboard macro in a reusable format. g. New user-settable variable `colored-stats', enables use of colored text to denote file types when displaying possible completions (colored analog of visible-stats). h. New user-settable variable `keyseq-timout', acts as an inter-character timeout when reading input or incremental search strings. i. New application-callable function: rl_clear_history. Clears the history list and frees all readline-associated private data. j. New user-settable variable, show-mode-in-prompt, adds a characters to the beginning of the prompt indicating the current editing mode. k. New application-settable variable: rl_input_available_hook; function to be called when readline detects there is data available on its input file descriptor. l. Readline calls an application-set event hook (rl_event_hook) after it gets a signal while reading input (read returns -1/EINTR but readline does not handle the signal immediately) to allow the application to handle or otherwise note it. m. If the user-settable variable `history-size' is set to a value less than 0, the history list size is unlimited. n. New application-settable variable: rl_signal_event_hook; function that is called when readline is reading terminal input and read(2) is interrupted by a signal. Currently not called for SIGHUP or SIGTERM.