This is a terse description of the new features added to readline-8.3 since
the release of readline-8.2.

New Features in Readline

a. Output a newline if there is no prompt and readline reads an empty line.

b. The history library falls back to stdio when writing the history list if
   mmap fails.

c. New bindable variable `search-ignore-case', causes readline to perform
   case-insensitive incremental and non-incremental history searches.

d. rl_full_quoting_desired: new application-settable variable, causes all
   completions to be quoted as if they were filenames.

e. rl_macro_display_hook: new application-settable function pointer, used if
   the application wants to print macro values itself instead of letting
   readline do it

f. rl_reparse_colors: new application-callable function, reparses $LS_COLORS
   (presumably after the user changes it)

g. rl_completion_rewrite_hook: new application-settable function pointer,
   called to modify the word being completed before comparing it against
   pathnames from the file system.

h. execute-named-command: a new bindable command that reads the name of a
   readline command from the standard input and executes it. Bound to M-x
   in emacs mode by default.

i. Incremental and non-incremental searches now allow ^V/^Q (or, in the former
   case, anything bound to quoted-insert) to quote characters in the search
   string.

-------------------------------------------------------------------------------
This is a terse description of the new features added to readline-8.2 since
the release of readline-8.1.

New Features in Readline

a. There is now an HS_HISTORY_VERSION containing the version number of the
   history library for applications to use.

b. History expansion better understands multiple history expansions that may
   contain strings that would ordinarily inhibit history expansion (e.g.,
   `abc!$!$').

c. There is a new framework for readline timeouts, including new public
   functions to set timeouts and query how much time is remaining before a
   timeout hits, and a hook function that can trigger when readline times
   out. There is a new state value to indicate a timeout.

d. Automatically bind termcap key sequences for page-up and page-down to
   history-search-backward and history-search-forward, respectively.

e. There is a new `fetch-history' bindable command that retrieves the history
   entry corresponding to its numeric argument. Negative arguments count back
   from the end of the history.

f. `vi-undo' is now a bindable command.

g. There is a new option: `enable-active-region'. This separates control of
   the active region and bracketed-paste. It has the same default value as
   bracketed-paste, and enabling bracketed paste enables the active region.
   Users can now turn off the active region while leaving bracketed paste
   enabled.

h. rl_completer_word_break_characters is now `const char *' like
   rl_basic_word_break_characters.

i. Readline looks in $LS_COLORS for a custom filename extension
   (*.readline-colored-completion-prefix) and uses that as the default color
   for the common prefix displayed when `colored-completion-prefix' is set.

j. Two new bindable string variables: active-region-start-color and
   active-region-end-color. The first sets the color used to display the
   active region; the second turns it off. If set, these are used in place
   of terminal standout mode.

k. New readline state (RL_STATE_EOF) and application-visible variable
   (rl_eof_found) to allow applications to detect when readline reads EOF
   before calling the deprep-terminal hook.

l. There is a new configuration option: --with-shared-termcap-library, which
   forces linking the shared readline library with the shared termcap (or
   curses/ncurses/termlib) library so applications don't have to do it.

m. Readline now checks for changes to locale settings (LC_ALL/LC_CTYPE/LANG)
   each time it is called, and modifies the appropriate locale-specific display
   and key binding variables when the locale changes.

-------------------------------------------------------------------------------
This is a terse description of the new features added to readline-8.1 since
the release of readline-8.0.

New Features in Readline

a. If a second consecutive completion attempt produces matches where the first
   did not, treat it as a new completion attempt and insert a match as
   appropriate.

b. Bracketed paste mode works in more places: incremental search strings, vi
   overstrike mode, character search, and reading numeric arguments.

c. Readline automatically switches to horizontal scrolling if the terminal has
   only one line.

d. Unbinding all key sequences bound to a particular readline function now
   descends into keymaps for multi-key sequences.

e. rl-clear-display: new bindable command that clears the screen and, if
   possible, the scrollback buffer (bound to emacs mode M-C-l by default).

f. New active mark and face feature: when enabled, it will highlight the text
   inserted by a bracketed paste (the `active region') and the text found by
   incremental and non-incremental history searches. This is tied to bracketed
   paste and can be disabled by turning off bracketed paste.

g. Readline sets the mark in several additional commands.

h. Bracketed paste mode is enabled by default. There is a configure-time
   option (--enable-bracketed-paste-default) to set the default to on or off.

i. Readline tries to take advantage of the more regular structure of UTF-8
   characters to identify the beginning and end of characters when moving
   through the line buffer.

j. The bindable operate-and-get-next command (and its default bindings) are
   now part of readline instead of a bash-specific addition.

k. The signal cleanup code now blocks SIGINT while processing after a SIGINT.  

-------------------------------------------------------------------------------
This is a terse description of the new features added to readline-8.0 since
the release of readline-7.0.

New Features in Readline

a. Non-incremental vi-mode search (`N', `n') can search for a shell pattern, as
   Posix specifies (uses fnmatch(3) if available).

b. There are new `next-screen-line' and `previous-screen-line' bindable
   commands, which move the cursor to the same column in the next, or previous,
   physical line, respectively.

c. There are default key bindings for control-arrow-key key combinations.

d. A negative argument (-N) to `quoted-insert' means to insert the next N
   characters using quoted-insert.

e. New public function: rl_check_signals(), which allows applications to
   respond to signals that readline catches while waiting for input using
   a custom read function.

f. There is new support for conditionally testing the readline version in an
   inputrc file, with a full set of arithmetic comparison operators available.

g. There is a simple variable comparison facility available for use within an
   inputrc file. Allowable operators are equality and inequality; string
   variables may be compared to a value; boolean variables must be compared to
   either `on' or `off'; variable names are separated from the operator by
   whitespace.

h. The history expansion library now understands command and process
   substitution and extended globbing and allows them to appear anywhere in a
   word.

i. The history library has a new variable that allows applications to set the
   initial quoting state, so quoting state can be inherited from a previous
   line.

j. Readline now allows application-defined keymap names; there is a new public
   function, rl_set_keymap_name(), to do that.

k. The "Insert" keypad key, if available, now puts readline into overwrite
   mode.

-------------------------------------------------------------------------------
This is a terse description of the new features added to readline-7.0 since
the release of readline-6.3.

New Features in Readline

a.  The history truncation code now uses the same error recovery mechanism as
    the history writing code, and restores the old version of the history file
    on error.  The error recovery mechanism handles symlinked history files.

b.  There is a new bindable variable, `enable-bracketed-paste', which enables
    support for a terminal's bracketed paste mode.

c.  The editing mode indicators can now be strings and are user-settable
    (new `emacs-mode-string', `vi-cmd-mode-string' and `vi-ins-mode-string'
    variables).  Mode strings can contain invisible character sequences.
    Setting mode strings to null strings restores the defaults.

d.  Prompt expansion adds the mode string to the last line of a multi-line
    prompt (one with embedded newlines).

e.  There is a new bindable variable, `colored-completion-prefix', which, if
    set, causes the common prefix of a set of possible completions to be
    displayed in color.

f.  There is a new bindable command `vi-yank-pop', a vi-mode version of emacs-
    mode yank-pop.

g.  The redisplay code underwent several efficiency improvements for multibyte
    locales.

h.  The insert-char function attempts to batch-insert all pending typeahead
    that maps to self-insert, as long as it is coming from the terminal.

i.  rl_callback_sigcleanup: a new application function that can clean up and
    unset any state set by readline's callback mode.  Intended to be used
    after a signal.

j.  If an incremental search string has its last character removed with DEL, the
    resulting empty search string no longer matches the previous line.

k.  If readline reads a history file that begins with `#' (or the value of
    the history comment character) and has enabled history timestamps, the history
    entries are assumed to be delimited by timestamps.  This allows multi-line
    history entries.

l.  Readline now throws an error if it parses a key binding without a terminating
    `:' or whitespace.

m.  The default binding for ^W in vi mode now uses word boundaries specified
    by Posix (vi-unix-word-rubout is bindable command name).

n.  rl_clear_visible_line: new application-callable function; clears all
    screen lines occupied by the current visible readline line.

o.  rl_tty_set_echoing: application-callable function that controls whether
    or not readline thinks it is echoing terminal output.

p.  Handle >| and strings of digits preceding and following redirection
    specifications as single tokens when tokenizing the line for history
    expansion.

q.  Fixed a bug with displaying completions when the prefix display length
    is greater than the length of the completions to be displayed.

r.  The :p history modifier now applies to the entire line, so any expansion
    specifying :p causes the line to be printed instead of expanded.

s.  New application-callable function: rl_pending_signal(): returns the signal
    number of any signal readline has caught but not yet handled.
    
t.  New application-settable variable: rl_persistent_signal_handlers: if set
    to a non-zero value, readline will enable the readline-6.2 signal handler
    behavior in callback mode: handlers are installed when
    rl_callback_handler_install is called and removed removed when a complete
    line has been read.

-------------------------------------------------------------------------------
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.

-------------------------------------------------------------------------------
This is a terse description of the new features added to readline-6.2 since
the release of readline-6.1.

a.  The history library does not try to write the history filename in the
    current directory if $HOME is unset.  This closes a potential security
    problem if the application does not specify a history filename.

b.  New bindable variable `completion-display-width' to set the number of
    columns used when displaying completions.

c.  New bindable variable `completion-case-map' to cause case-insensitive
    completion to treat `-' and `_' as identical.

d.  There are new bindable vi-mode command names to avoid readline's case-
    insensitive matching not allowing them to be bound separately.

e.  New bindable variable `menu-complete-display-prefix' causes the menu
    completion code to display the common prefix of the possible completions
    before cycling through the list, instead of after.

-------------------------------------------------------------------------------
This is a terse description of the new features added to readline-6.1 since
the release of readline-6.0.

New Features in Readline

a.  New bindable function: menu-complete-backward.

b.  In the vi insertion keymap, C-n is now bound to menu-complete by default,
    and C-p to menu-complete-backward.

c.  When in vi command mode, repeatedly hitting ESC now does nothing, even
    when ESC introduces a bound key sequence.  This is closer to how
    historical vi behaves.

d.  New bindable function: skip-csi-sequence.  Can be used as a default to
    consume key sequences generated by keys like Home and End without having
    to bind all keys.

e.  New application-settable function: rl_filename_rewrite_hook.  Can be used
    to rewrite or modify filenames read from the file system before they are
    compared to the word to be completed.

f.  New bindable variable: skip-completed-text, active when completing in the
    middle of a word.  If enabled, it means that characters in the completion
    that match characters in the remainder of the word are "skipped" rather
    than inserted into the line.

g.  The pre-readline-6.0 version of menu completion is available as
    "old-menu-complete" for users who do not like the readline-6.0 version.

h.  New bindable variable: echo-control-characters.  If enabled, and the
    tty ECHOCTL bit is set, controls the echoing of characters corresponding
    to keyboard-generated signals.

i.  New bindable variable: enable-meta-key.  Controls whether or not readline
    sends the smm/rmm sequences if the terminal indicates it has a meta key
    that enables eight-bit characters.

-------------------------------------------------------------------------------
This is a terse description of the new features added to readline-6.0 since
the release of readline-5.2.

New Features in Readline

a.  A new variable, rl_sort_completion_matches; allows applications to inhibit
    match list sorting (but beware: some things don't work right if
    applications do this).

b.  A new variable, rl_completion_invoking_key; allows applications to discover
    the key that invoked rl_complete or rl_menu_complete.

c.  The functions rl_block_sigint and rl_release_sigint are now public and
    available to calling applications who want to protect critical sections
    (like redisplay).

d.  The functions rl_save_state and rl_restore_state are now public and
    available to calling applications; documented rest of readline's state
    flag values.

e.  A new user-settable variable, `history-size', allows setting the maximum
    number of entries in the history list.

f.  There is a new implementation of menu completion, with several improvements
    over the old; the most notable improvement is a better `completions
    browsing' mode.

g.  The menu completion code now uses the rl_menu_completion_entry_function
    variable, allowing applications to provide their own menu completion
    generators.

h.  There is support for replacing a prefix  of a pathname with a `...' when
    displaying possible completions.  This is controllable by setting the
    `completion-prefix-display-length' variable.  Matches with a common prefix
    longer than this value have the common prefix replaced with `...'.

i.  There is a new `revert-all-at-newline' variable.  If enabled, readline will
    undo all outstanding changes to all history lines when `accept-line' is
    executed.

-------------------------------------------------------------------------------
This is a terse description of the new features added to readline-5.2 since
the release of readline-5.1.

New Features in Readline

a.  Calling applications can now set the keyboard timeout to 0, allowing
    poll-like behavior.

b.  The value of SYS_INPUTRC (configurable at compilation time) is now used as
    the default last-ditch startup file.

c.  The history file reading functions now allow windows-like \r\n line
    terminators.

-------------------------------------------------------------------------------
This is a terse description of the new features added to readline-5.1 since
the release of readline-5.0.

New Features in Readline

a.  The key sequence sent by the keypad `delete' key is now automatically   
    bound to delete-char.

b.  A negative argument to menu-complete now cycles backward through the
    completion list.

c.  A new bindable readline variable:  bind-tty-special-chars.  If non-zero,
    readline will bind the terminal special characters to their readline
    equivalents when it's called (on by default).

d.  New bindable command: vi-rubout.  Saves deleted text for possible  
    reinsertion, as with any vi-mode `text modification' command; `X' is bound
    to this in vi command mode.

e.  If the rl_completion_query_items is set to a value < 0, readline never
    asks the user whether or not to view the possible completions.

f.  New application-callable auxiliary function, rl_variable_value, returns
    a string corresponding to a readline variable's value.

g.  When parsing inputrc files and variable binding commands, the parser
    strips trailing whitespace from values assigned to boolean variables
    before checking them.

h.  A new external application-controllable variable that allows the LINES
    and COLUMNS environment variables to set the window size regardless of
    what the kernel returns.


-------------------------------------------------------------------------------
This is a terse description of the new features added to readline-5.0 since
the release of readline-4.3.

New Features in Readline

a.  History expansion has a new `a' modifier equivalent to the `g' modifier
    for compatibility with the BSD csh.

b.  History expansion has a new `G' modifier equivalent to the BSD csh `g'
    modifier, which performs a substitution once per word.

c.  All non-incremental search operations may now undo the operation of
    replacing the current line with the history line.

d.  The text inserted by an `a' command in vi mode can be reinserted with
    `.'.

e.  New bindable variable, `show-all-if-unmodified'.  If set, the readline
    completer will list possible completions immediately if there is more
    than one completion and partial completion cannot be performed.

f.  There is a new application-callable `free_history_entry()' function.

g.  History list entries now contain timestamp information; the history file
    functions know how to read and write timestamp information associated
    with each entry.

h.  Four new key binding functions have been added:

	rl_bind_key_if_unbound()
	rl_bind_key_if_unbound_in_map()
	rl_bind_keyseq_if_unbound()
	rl_bind_keyseq_if_unbound_in_map()

i.  New application variable, rl_completion_quote_character, set to any
    quote character readline finds before it calls the application completion
    function.

j.  New application variable, rl_completion_suppress_quote, settable by an   
    application completion function.  If set to non-zero, readline does not
    attempt to append a closing quote to a completed word.
    
k.  New application variable, rl_completion_found_quote, set to a non-zero
    value if readline determines that the word to be completed is quoted.
    Set before readline calls any application completion function.

l.  New function hook, rl_completion_word_break_hook, called when readline
    needs to break a line into words when completion is attempted.  Allows
    the word break characters to vary based on position in the line.

m.  New bindable command: unix-filename-rubout.  Does the same thing as
    unix-word-rubout, but adds `/' to the set of word delimiters.

n.  When listing completions, directories have a `/' appended if the
    `mark-directories' option has been enabled.
