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This is ./gdb.info, produced by makeinfo version 4.0 from gdb.texinfo.

INFO-DIR-SECTION Programming & development tools.

START-INFO-DIR-ENTRY

* Gdb: (gdb).                     The GNU debugger.

END-INFO-DIR-ENTRY

   This file documents the GNU debugger GDB.

   This is the Eighth Edition, March 2000, of `Debugging with GDB: the

GNU Source-Level Debugger' for GDB Version 5.0.

   Copyright (C) 1988-2000 Free Software Foundation, Inc.

   Permission is granted to make and distribute verbatim copies of this

manual provided the copyright notice and this permission notice are

preserved on all copies.

   Permission is granted to copy and distribute modified versions of

this manual under the conditions for verbatim copying, provided also

that the entire resulting derived work is distributed under the terms

of a permission notice identical to this one.

   Permission is granted to copy and distribute translations of this

manual into another language, under the above conditions for modified

versions.

File: gdb.info,  Node: Readline Init File,  Next: Bindable Readline Commands,  Prev: Readline Interaction,  Up: Command Line Editing

Readline Init File

==================

   Although the Readline library comes with a set of `emacs'-like

keybindings installed by default, it is possible to use a different set

of keybindings.  Any user can customize programs that use Readline by

putting commands in an "inputrc" file in his home directory.  The name

of this file is taken from the value of the environment variable

`INPUTRC'.  If that variable is unset, the default is `~/.inputrc'.

   When a program which uses the Readline library starts up, the init

file is read, and the key bindings are set.

   In addition, the `C-x C-r' command re-reads this init file, thus

incorporating any changes that you might have made to it.

* Menu:

* Readline Init File Syntax::   Syntax for the commands in the inputrc file.

* Conditional Init Constructs:: Conditional key bindings in the inputrc file.

* Sample Init File::            An example inputrc file.

File: gdb.info,  Node: Readline Init File Syntax,  Next: Conditional Init Constructs,  Up: Readline Init File

Readline Init File Syntax

-------------------------

   There are only a few basic constructs allowed in the Readline init

file.  Blank lines are ignored.  Lines beginning with a `#' are

comments.  Lines beginning with a `$' indicate conditional constructs

(*note Conditional Init Constructs::).  Other lines denote variable

settings and key bindings.

Variable Settings

     You can modify the run-time behavior of Readline by altering the

     values of variables in Readline using the `set' command within the

     init file.  Here is how to change from the default Emacs-like key

     binding to use `vi' line editing commands:

          set editing-mode vi

     A great deal of run-time behavior is changeable with the following

     variables.

    `bell-style'

          Controls what happens when Readline wants to ring the

          terminal bell.  If set to `none', Readline never rings the

          bell.  If set to `visible', Readline uses a visible bell if

          one is available.  If set to `audible' (the default),

          Readline attempts to ring the terminal's bell.

    `comment-begin'

          The string to insert at the beginning of the line when the

          `insert-comment' command is executed.  The default value is

          `"#"'.

    `completion-ignore-case'

          If set to `on', Readline performs filename matching and

          completion in a case-insensitive fashion.  The default value

          is `off'.

    `completion-query-items'

          The number of possible completions that determines when the

          user is asked whether he wants to see the list of

          possibilities.  If the number of possible completions is

          greater than this value, Readline will ask the user whether

          or not he wishes to view them; otherwise, they are simply

          listed.  The default limit is `100'.

    `convert-meta'

          If set to `on', Readline will convert characters with the

          eighth bit set to an ASCII key sequence by stripping the

          eighth bit and prepending an  character, converting them

          to a meta-prefixed key sequence.  The default value is `on'.

    `disable-completion'

          If set to `On', Readline will inhibit word completion.

          Completion  characters will be inserted into the line as if

          they had been mapped to `self-insert'.  The default is `off'.

    `editing-mode'

          The `editing-mode' variable controls which default set of key

          bindings is used.  By default, Readline starts up in Emacs

          editing mode, where the keystrokes are most similar to Emacs.

          This variable can be set to either `emacs' or `vi'.

    `enable-keypad'

          When set to `on', Readline will try to enable the application

          keypad when it is called.  Some systems need this to enable

          the arrow keys.  The default is `off'.

    `expand-tilde'

          If set to `on', tilde expansion is performed when Readline

          attempts word completion.  The default is `off'.

    `horizontal-scroll-mode'

          This variable can be set to either `on' or `off'.  Setting it

          to `on' means that the text of the lines being edited will

          scroll horizontally on a single screen line when they are

          longer than the width of the screen, instead of wrapping onto

          a new screen line.  By default, this variable is set to `off'.

    `input-meta'

          If set to `on', Readline will enable eight-bit input (it will

          not strip the eighth bit from the characters it reads),

          regardless of what the terminal claims it can support.  The

          default value is `off'.  The name `meta-flag' is a synonym

          for this variable.

    `isearch-terminators'

          The string of characters that should terminate an incremental

          search without subsequently executing the character as a

          command (*note Searching::).  If this variable has not been

          given a value, the characters  and  will terminate

          an incremental search.

    `keymap'

          Sets Readline's idea of the current keymap for key binding

          commands.  Acceptable `keymap' names are `emacs',

          `emacs-standard', `emacs-meta', `emacs-ctlx', `vi',

          `vi-command', and `vi-insert'.  `vi' is equivalent to

          `vi-command'; `emacs' is equivalent to `emacs-standard'.  The

          default value is `emacs'.  The value of the `editing-mode'

          variable also affects the default keymap.

    `mark-directories'

          If set to `on', completed directory names have a slash

          appended.  The default is `on'.

    `mark-modified-lines'

          This variable, when set to `on', causes Readline to display an

          asterisk (`*') at the start of history lines which have been

          modified.  This variable is `off' by default.

    `output-meta'

          If set to `on', Readline will display characters with the

          eighth bit set directly rather than as a meta-prefixed escape

          sequence.  The default is `off'.

    `print-completions-horizontally'

          If set to `on', Readline will display completions with matches

          sorted horizontally in alphabetical order, rather than down

          the screen.  The default is `off'.

    `show-all-if-ambiguous'

          This alters the default behavior of the completion functions.

          If set to `on', words which have more than one possible

          completion cause the matches to be listed immediately instead

          of ringing the bell.  The default value is `off'.

    `visible-stats'

          If set to `on', a character denoting a file's type is

          appended to the filename when listing possible completions.

          The default is `off'.

Key Bindings

     The syntax for controlling key bindings in the init file is

     simple.  First you have to know the name of the command that you

     want to change.  The following sections contain tables of the

     command name, the default keybinding, if any, and a short

     description of what the command does.

     Once you know the name of the command, simply place the name of

     the key you wish to bind the command to, a colon, and then the

     name of the command on a line in the init file.  The name of the

     key can be expressed in different ways, depending on which is most

     comfortable for you.

    KEYNAME: FUNCTION-NAME or MACRO

          KEYNAME is the name of a key spelled out in English.  For

          example:

               Control-u: universal-argument

               Meta-Rubout: backward-kill-word

               Control-o: "> output"

          In the above example,  is bound to the function

          `universal-argument', and  is bound to run the macro

          expressed on the right hand side (that is, to insert the text

          `> output' into the line).

    "KEYSEQ": FUNCTION-NAME or MACRO

          KEYSEQ differs from KEYNAME above in that strings denoting an

          entire key sequence can be specified, by placing the key

          sequence in double quotes.  Some GNU Emacs style key escapes

          can be used, as in the following example, but the special

          character names are not recognized.

               "\C-u": universal-argument

               "\C-x\C-r": re-read-init-file

               "\e[11~": "Function Key 1"

          In the above example,  is bound to the function

          `universal-argument' (just as it was in the first example),

          ` ' is bound to the function `re-read-init-file',

          and ` <[> <1> <1> <~>' is bound to insert the text

          `Function Key 1'.

     The following GNU Emacs style escape sequences are available when

     specifying key sequences:

    `\C-'

          control prefix

    `\M-'

          meta prefix

    `\e'

          an escape character

    `\\'

          backslash

    `\"'

          <">

    `\''

          <'>

     In addition to the GNU Emacs style escape sequences, a second set

     of backslash escapes is available:

    `\a'

          alert (bell)

    `\b'

          backspace

    `\d'

          delete

    `\f'

          form feed

    `\n'

          newline

    `\r'

          carriage return

    `\t'

          horizontal tab

    `\v'

          vertical tab

    `\NNN'

          the character whose ASCII code is the octal value NNN (one to

          three digits)

    `\xNNN'

          the character whose ASCII code is the hexadecimal value NNN

          (one to three digits)

     When entering the text of a macro, single or double quotes must be

     used to indicate a macro definition.  Unquoted text is assumed to

     be a function name.  In the macro body, the backslash escapes

     described above are expanded.  Backslash will quote any other

     character in the macro text, including `"' and `''.  For example,

     the following binding will make `C-x \' insert a single `\' into

     the line:

          "\C-x\\": "\\"

File: gdb.info,  Node: Conditional Init Constructs,  Next: Sample Init File,  Prev: Readline Init File Syntax,  Up: Readline Init File

Conditional Init Constructs

---------------------------

   Readline implements a facility similar in spirit to the conditional

compilation features of the C preprocessor which allows key bindings

and variable settings to be performed as the result of tests.  There

are four parser directives used.

`$if'

     The `$if' construct allows bindings to be made based on the

     editing mode, the terminal being used, or the application using

     Readline.  The text of the test extends to the end of the line; no

     characters are required to isolate it.

    `mode'

          The `mode=' form of the `$if' directive is used to test

          whether Readline is in `emacs' or `vi' mode.  This may be

          used in conjunction with the `set keymap' command, for

          instance, to set bindings in the `emacs-standard' and

          `emacs-ctlx' keymaps only if Readline is starting out in

          `emacs' mode.

    `term'

          The `term=' form may be used to include terminal-specific key

          bindings, perhaps to bind the key sequences output by the

          terminal's function keys.  The word on the right side of the

          `=' is tested against both the full name of the terminal and

          the portion of the terminal name before the first `-'.  This

          allows `sun' to match both `sun' and `sun-cmd', for instance.

    `application'

          The APPLICATION construct is used to include

          application-specific settings.  Each program using the

          Readline library sets the APPLICATION NAME, and you can test

          for it.  This could be used to bind key sequences to

          functions useful for a specific program.  For instance, the

          following command adds a key sequence that quotes the current

          or previous word in Bash:

               $if Bash

               # Quote the current or previous word

               "\C-xq": "\eb\"\ef\""

               $endif

`$endif'

     This command, as seen in the previous example, terminates an `$if'

     command.

`$else'

     Commands in this branch of the `$if' directive are executed if the

     test fails.

`$include'

     This directive takes a single filename as an argument and reads

     commands and bindings from that file.

          $include /etc/inputrc

File: gdb.info,  Node: Sample Init File,  Prev: Conditional Init Constructs,  Up: Readline Init File

Sample Init File

----------------

   Here is an example of an inputrc file.  This illustrates key

binding, variable assignment, and conditional syntax.

     # This file controls the behaviour of line input editing for

     # programs that use the Gnu Readline library.  Existing programs

     # include FTP, Bash, and Gdb.

     #

     # You can re-read the inputrc file with C-x C-r.

     # Lines beginning with '#' are comments.

     #

     # First, include any systemwide bindings and variable assignments from

     # /etc/Inputrc

     $include /etc/Inputrc

     #

     # Set various bindings for emacs mode.

     set editing-mode emacs

     $if mode=emacs

     Meta-Control-h:    backward-kill-word      Text after the function name is ignored

     #

     # Arrow keys in keypad mode

     #

     #"\M-OD":        backward-char

     #"\M-OC":        forward-char

     #"\M-OA":        previous-history

     #"\M-OB":        next-history

     #

     # Arrow keys in ANSI mode

     #

     "\M-[D":        backward-char

     "\M-[C":        forward-char

     "\M-[A":        previous-history

     "\M-[B":        next-history

     #

     # Arrow keys in 8 bit keypad mode

     #

     #"\M-\C-OD":       backward-char

     #"\M-\C-OC":       forward-char

     #"\M-\C-OA":       previous-history

     #"\M-\C-OB":       next-history

     #

     # Arrow keys in 8 bit ANSI mode

     #

     #"\M-\C-[D":       backward-char

     #"\M-\C-[C":       forward-char

     #"\M-\C-[A":       previous-history

     #"\M-\C-[B":       next-history

     C-q: quoted-insert

     $endif

     # An old-style binding.  This happens to be the default.

     TAB: complete

     # Macros that are convenient for shell interaction

     $if Bash

     # edit the path

     "\C-xp": "PATH=${PATH}\e\C-e\C-a\ef\C-f"

     # prepare to type a quoted word -- insert open and close double quotes

     # and move to just after the open quote

     "\C-x\"": "\"\"\C-b"

     # insert a backslash (testing backslash escapes in sequences and macros)

     "\C-x\\": "\\"

     # Quote the current or previous word

     "\C-xq": "\eb\"\ef\""

     # Add a binding to refresh the line, which is unbound

     "\C-xr": redraw-current-line

     # Edit variable on current line.

     "\M-\C-v": "\C-a\C-k$\C-y\M-\C-e\C-a\C-y="

     $endif

     # use a visible bell if one is available

     set bell-style visible

     # don't strip characters to 7 bits when reading

     set input-meta on

     # allow iso-latin1 characters to be inserted rather than converted to

     # prefix-meta sequences

     set convert-meta off

     # display characters with the eighth bit set directly rather than

     # as meta-prefixed characters

     set output-meta on

     # if there are more than 150 possible completions for a word, ask the

     # user if he wants to see all of them

     set completion-query-items 150

     # For FTP

     $if Ftp

     "\C-xg": "get \M-?"

     "\C-xt": "put \M-?"

     "\M-.": yank-last-arg

     $endif

File: gdb.info,  Node: Bindable Readline Commands,  Next: Readline vi Mode,  Prev: Readline Init File,  Up: Command Line Editing

Bindable Readline Commands

==========================

* Menu:

* Commands For Moving::         Moving about the line.

* Commands For History::        Getting at previous lines.

* Commands For Text::           Commands for changing text.

* Commands For Killing::        Commands for killing and yanking.

* Numeric Arguments::           Specifying numeric arguments, repeat counts.

* Commands For Completion::     Getting Readline to do the typing for you.

* Keyboard Macros::             Saving and re-executing typed characters

* Miscellaneous Commands::      Other miscellaneous commands.

   This section describes Readline commands that may be bound to key

sequences.

File: gdb.info,  Node: Commands For Moving,  Next: Commands For History,  Up: Bindable Readline Commands

Commands For Moving

-------------------

`beginning-of-line (C-a)'

     Move to the start of the current line.

`end-of-line (C-e)'

     Move to the end of the line.

`forward-char (C-f)'

     Move forward a character.

`backward-char (C-b)'

     Move back a character.

`forward-word (M-f)'

     Move forward to the end of the next word.  Words are composed of

     letters and digits.

`backward-word (M-b)'

     Move back to the start of this, or the previous, word.  Words are

     composed of letters and digits.

`clear-screen (C-l)'

     Clear the screen and redraw the current line, leaving the current

     line at the top of the screen.

`redraw-current-line ()'

     Refresh the current line.  By default, this is unbound.

File: gdb.info,  Node: Commands For History,  Next: Commands For Text,  Prev: Commands For Moving,  Up: Bindable Readline Commands

Commands For Manipulating The History

-------------------------------------

`accept-line (Newline, Return)'

     Accept the line regardless of where the cursor is.  If this line is

     non-empty, add it to the history list.  If this line was a history

     line, then restore the history line to its original state.

`previous-history (C-p)'

     Move `up' through the history list.

`next-history (C-n)'

     Move `down' through the history list.

`beginning-of-history (M-<)'

     Move to the first line in the history.

`end-of-history (M->)'

     Move to the end of the input history, i.e., the line currently

     being entered.

`reverse-search-history (C-r)'

     Search backward starting at the current line and moving `up'

     through the history as necessary.  This is an incremental search.

`forward-search-history (C-s)'

     Search forward starting at the current line and moving `down'

     through the the history as necessary.  This is an incremental

     search.

`non-incremental-reverse-search-history (M-p)'

     Search backward starting at the current line and moving `up'

     through the history as necessary using a non-incremental search

     for a string supplied by the user.

`non-incremental-forward-search-history (M-n)'

     Search forward starting at the current line and moving `down'

     through the the history as necessary using a non-incremental search

     for a string supplied by the user.

`history-search-forward ()'

     Search forward through the history for the string of characters

     between the start of the current line and the current cursor

     position (the POINT).  This is a non-incremental search.  By

     default, this command is unbound.

`history-search-backward ()'

     Search backward through the history for the string of characters

     between the start of the current line and the point.  This is a

     non-incremental search.  By default, this command is unbound.

`yank-nth-arg (M-C-y)'

     Insert the first argument to the previous command (usually the

     second word on the previous line).  With an argument N, insert the

     Nth word from the previous command (the words in the previous

     command begin with word 0).  A negative argument inserts the Nth

     word from the end of the previous command.

`yank-last-arg (M-., M-_)'

     Insert last argument to the previous command (the last word of the

     previous history entry).  With an argument, behave exactly like

     `yank-nth-arg'.  Successive calls to `yank-last-arg' move back

     through the history list, inserting the last argument of each line

     in turn.

File: gdb.info,  Node: Commands For Text,  Next: Commands For Killing,  Prev: Commands For History,  Up: Bindable Readline Commands

Commands For Changing Text

--------------------------

`delete-char (C-d)'

     Delete the character under the cursor.  If the cursor is at the

     beginning of the line, there are no characters in the line, and

     the last character typed was not bound to `delete-char', then

     return `EOF'.

`backward-delete-char (Rubout)'

     Delete the character behind the cursor.  A numeric argument means

     to kill the characters instead of deleting them.

`forward-backward-delete-char ()'

     Delete the character under the cursor, unless the cursor is at the

     end of the line, in which case the character behind the cursor is

     deleted.  By default, this is not bound to a key.

`quoted-insert (C-q, C-v)'

     Add the next character typed to the line verbatim.  This is how to

     insert key sequences like , for example.

`tab-insert (M-TAB)'

     Insert a tab character.

`self-insert (a, b, A, 1, !, ...)'

     Insert yourself.

`transpose-chars (C-t)'

     Drag the character before the cursor forward over the character at

     the cursor, moving the cursor forward as well.  If the insertion

     point is at the end of the line, then this transposes the last two

     characters of the line.  Negative arguments don't work.

`transpose-words (M-t)'

     Drag the word behind the cursor past the word in front of the

     cursor moving the cursor over that word as well.

`upcase-word (M-u)'

     Uppercase the current (or following) word.  With a negative

     argument, uppercase the previous word, but do not move the cursor.

`downcase-word (M-l)'

     Lowercase the current (or following) word.  With a negative

     argument, lowercase the previous word, but do not move the cursor.

`capitalize-word (M-c)'

     Capitalize the current (or following) word.  With a negative

     argument, capitalize the previous word, but do not move the cursor.

File: gdb.info,  Node: Commands For Killing,  Next: Numeric Arguments,  Prev: Commands For Text,  Up: Bindable Readline Commands

Killing And Yanking

-------------------

`kill-line (C-k)'

     Kill the text from the current cursor position to the end of the

     line.

`backward-kill-line (C-x Rubout)'

     Kill backward to the beginning of the line.

`unix-line-discard (C-u)'

     Kill backward from the cursor to the beginning of the current line.

     The killed text is saved on the kill-ring.

`kill-whole-line ()'

     Kill all characters on the current line, no matter where the

     cursor is.  By default, this is unbound.

`kill-word (M-d)'

     Kill from the cursor to the end of the current word, or if between

     words, to the end of the next word.  Word boundaries are the same

     as `forward-word'.

`backward-kill-word (M-DEL)'

     Kill the word behind the cursor.  Word boundaries are the same as

     `backward-word'.

`unix-word-rubout (C-w)'

     Kill the word behind the cursor, using white space as a word

     boundary.  The killed text is saved on the kill-ring.

`delete-horizontal-space ()'

     Delete all spaces and tabs around point.  By default, this is

     unbound.

`kill-region ()'

     Kill the text between the point and the _mark_ (saved cursor

     position).  This text is referred to as the REGION.  By default,

     this command is unbound.

`copy-region-as-kill ()'

     Copy the text in the region to the kill buffer, so it can be yanked

     right away.  By default, this command is unbound.

`copy-backward-word ()'

     Copy the word before point to the kill buffer.  The word

     boundaries are the same as `backward-word'.  By default, this

     command is unbound.

`copy-forward-word ()'

     Copy the word following point to the kill buffer.  The word

     boundaries are the same as `forward-word'.  By default, this

     command is unbound.

`yank (C-y)'

     Yank the top of the kill ring into the buffer at the current

     cursor position.

`yank-pop (M-y)'

     Rotate the kill-ring, and yank the new top.  You can only do this

     if the prior command is yank or yank-pop.

File: gdb.info,  Node: Numeric Arguments,  Next: Commands For Completion,  Prev: Commands For Killing,  Up: Bindable Readline Commands

Specifying Numeric Arguments

----------------------------

`digit-argument (M-0, M-1, ... M--)'

     Add this digit to the argument already accumulating, or start a new

     argument.   starts a negative argument.

`universal-argument ()'

     This is another way to specify an argument.  If this command is

     followed by one or more digits, optionally with a leading minus

     sign, those digits define the argument.  If the command is

     followed by digits, executing `universal-argument' again ends the

     numeric argument, but is otherwise ignored.  As a special case, if

     this command is immediately followed by a character that is

     neither a digit or minus sign, the argument count for the next

     command is multiplied by four.  The argument count is initially

     one, so executing this function the first time makes the argument

     count four, a second time makes the argument count sixteen, and so

     on.  By default, this is not bound to a key.

File: gdb.info,  Node: Commands For Completion,  Next: Keyboard Macros,  Prev: Numeric Arguments,  Up: Bindable Readline Commands

Letting Readline Type For You

-----------------------------

`complete (TAB)'

     Attempt to do completion on the text before the cursor.  This is

     application-specific.  Generally, if you are typing a filename

     argument, you can do filename completion; if you are typing a

     command, you can do command completion; if you are typing in a

     symbol to GDB, you can do symbol name completion; if you are

     typing in a variable to Bash, you can do variable name completion,

     and so on.

`possible-completions (M-?)'

     List the possible completions of the text before the cursor.

`insert-completions (M-*)'

     Insert all completions of the text before point that would have

     been generated by `possible-completions'.

`menu-complete ()'

     Similar to `complete', but replaces the word to be completed with

     a single match from the list of possible completions.  Repeated

     execution of `menu-complete' steps through the list of possible

     completions, inserting each match in turn.  At the end of the list

     of completions, the bell is rung and the original text is restored.

     An argument of N moves N positions forward in the list of matches;

     a negative argument may be used to move backward through the list.

     This command is intended to be bound to `TAB', but is unbound by

     default.

`delete-char-or-list ()'

     Deletes the character under the cursor if not at the beginning or

     end of the line (like `delete-char').  If at the end of the line,

     behaves identically to `possible-completions'.  This command is

     unbound by default.

File: gdb.info,  Node: Keyboard Macros,  Next: Miscellaneous Commands,  Prev: Commands For Completion,  Up: Bindable Readline Commands

Keyboard Macros

---------------

`start-kbd-macro (C-x ()'

     Begin saving the characters typed into the current keyboard macro.

`end-kbd-macro (C-x ))'

     Stop saving the characters typed into the current keyboard macro

     and save the definition.

`call-last-kbd-macro (C-x e)'

     Re-execute the last keyboard macro defined, by making the

     characters in the macro appear as if typed at the keyboard.

File: gdb.info,  Node: Miscellaneous Commands,  Prev: Keyboard Macros,  Up: Bindable Readline Commands

Some Miscellaneous Commands

---------------------------

`re-read-init-file (C-x C-r)'

     Read in the contents of the inputrc file, and incorporate any

     bindings or variable assignments found there.

`abort (C-g)'

     Abort the current editing command and ring the terminal's bell

     (subject to the setting of `bell-style').

`do-uppercase-version (M-a, M-b, M-X, ...)'

     If the metafied character X is lowercase, run the command that is

     bound to the corresponding uppercase character.

`prefix-meta (ESC)'

     Make the next character typed be metafied.  This is for keyboards

     without a meta key.  Typing `ESC f' is equivalent to typing `M-f'.

`undo (C-_, C-x C-u)'

     Incremental undo, separately remembered for each line.

`revert-line (M-r)'

     Undo all changes made to this line.  This is like executing the

     `undo' command enough times to get back to the beginning.

`tilde-expand (M-~)'

     Perform tilde expansion on the current word.

`set-mark (C-@)'

     Set the mark to the current point.  If a numeric argument is

     supplied, the mark is set to that position.

`exchange-point-and-mark (C-x C-x)'

     Swap the point with the mark.  The current cursor position is set

     to the saved position, and the old cursor position is saved as the

     mark.

`character-search (C-])'

     A character is read and point is moved to the next occurrence of

     that character.  A negative count searches for previous

     occurrences.

`character-search-backward (M-C-])'

     A character is read and point is moved to the previous occurrence

     of that character.  A negative count searches for subsequent

     occurrences.

`insert-comment (M-#)'

     The value of the `comment-begin' variable is inserted at the

     beginning of the current line, and the line is accepted as if a

     newline had been typed.

`dump-functions ()'

     Print all of the functions and their key bindings to the Readline

     output stream.  If a numeric argument is supplied, the output is

     formatted in such a way that it can be made part of an INPUTRC

     file.  This command is unbound by default.

`dump-variables ()'

     Print all of the settable variables and their values to the

     Readline output stream.  If a numeric argument is supplied, the

     output is formatted in such a way that it can be made part of an

     INPUTRC file.  This command is unbound by default.

`dump-macros ()'

     Print all of the Readline key sequences bound to macros and the

     strings they ouput.  If a numeric argument is supplied, the output

     is formatted in such a way that it can be made part of an INPUTRC

     file.  This command is unbound by default.

File: gdb.info,  Node: Readline vi Mode,  Prev: Bindable Readline Commands,  Up: Command Line Editing

Readline vi Mode

================

   While the Readline library does not have a full set of `vi' editing

functions, it does contain enough to allow simple editing of the line.

The Readline `vi' mode behaves as specified in the POSIX 1003.2

standard.

   In order to switch interactively between `emacs' and `vi' editing

modes, use the command M-C-j (toggle-editing-mode).  The Readline

default is `emacs' mode.

   When you enter a line in `vi' mode, you are already placed in

`insertion' mode, as if you had typed an `i'.  Pressing  switches

you into `command' mode, where you can edit the text of the line with

the standard `vi' movement keys, move to previous history lines with

`k' and subsequent lines with `j', and so forth.

File: gdb.info,  Node: Using History Interactively,  Next: Installing GDB,  Prev: Command Line Editing,  Up: Top

Using History Interactively

***************************

   This chapter describes how to use the GNU History Library

interactively, from a user's standpoint.  It should be considered a

user's guide.

* Menu:

* History Interaction::         What it feels like using History as a user.

File: gdb.info,  Node: History Interaction,  Up: Using History Interactively

History Expansion

=================

   The History library provides a history expansion feature that is

similar to the history expansion provided by `csh'.  This section

describes the syntax used to manipulate the history information.

   History expansions introduce words from the history list into the

input stream, making it easy to repeat commands, insert the arguments

to a previous command into the current input line, or fix errors in

previous commands quickly.

   History expansion takes place in two parts.  The first is to

determine which line from the history list should be used during

substitution.  The second is to select portions of that line for

inclusion into the current one.  The line selected from the history is

called the "event", and the portions of that line that are acted upon

are called "words".  Various "modifiers" are available to manipulate

the selected words.  The line is broken into words in the same fashion

that Bash does, so that several words surrounded by quotes are

considered one word.  History expansions are introduced by the

appearance of the history expansion character, which is `!' by default.

* Menu:

* Event Designators::   How to specify which history line to use.

* Word Designators::    Specifying which words are of interest.

* Modifiers::           Modifying the results of substitution.

File: gdb.info,  Node: Event Designators,  Next: Word Designators,  Up: History Interaction

Event Designators

-----------------

   An event designator is a reference to a command line entry in the

history list.

`!'

     Start a history substitution, except when followed by a space, tab,

     the end of the line, `=' or `('.

`!N'

     Refer to command line N.