gdb: Command History
22.3 Command History
====================
GDB can keep track of the commands you type during your debugging
sessions, so that you can be certain of precisely what happened. Use
these commands to manage the GDB command history facility.
GDB uses the GNU History library, a part of the Readline package, to
provide the history facility. 
(history)Using History
Interactively, for the detailed description of the History library.
To issue a command to GDB without affecting certain aspects of the
state which is seen by users, prefix it with 'server ' (Server
Prefix). This means that this command will not affect the command
history, nor will it affect GDB's notion of which command to repeat if
<RET> is pressed on a line by itself.
The server prefix does not affect the recording of values into the
value history; to print a value without recording it into the value
history, use the 'output' command instead of the 'print' command.
Here is the description of GDB commands related to command history.
'set history filename FNAME'
Set the name of the GDB command history file to FNAME. This is the
file where GDB reads an initial command history list, and where it
writes the command history from this session when it exits. You
can access this list through history expansion or through the
history command editing characters listed below. This file
defaults to the value of the environment variable 'GDBHISTFILE', or
to './.gdb_history' ('./_gdb_history' on MS-DOS) if this variable
is not set.
'set history save'
'set history save on'
Record command history in a file, whose name may be specified with
the 'set history filename' command. By default, this option is
disabled.
'set history save off'
Stop recording command history in a file.
'set history size SIZE'
'set history size unlimited'
Set the number of commands which GDB keeps in its history list.
This defaults to the value of the environment variable
'GDBHISTSIZE', or to 256 if this variable is not set. Non-numeric
values of 'GDBHISTSIZE' are ignored. If SIZE is 'unlimited' or if
'GDBHISTSIZE' is either a negative number or the empty string, then
the number of commands GDB keeps in the history list is unlimited.
'set history remove-duplicates COUNT'
'set history remove-duplicates unlimited'
Control the removal of duplicate history entries in the command
history list. If COUNT is non-zero, GDB will look back at the last
COUNT history entries and remove the first entry that is a
duplicate of the current entry being added to the command history
list. If COUNT is 'unlimited' then this lookbehind is unbounded.
If COUNT is 0, then removal of duplicate history entries is
disabled.
Only history entries added during the current session are
considered for removal. This option is set to 0 by default.
History expansion assigns special meaning to the character '!'.
(history)Event Designators, for more details.
Since '!' is also the logical not operator in C, history expansion is
off by default. If you decide to enable history expansion with the 'set
history expansion on' command, you may sometimes need to follow '!'
(when it is used as logical not, in an expression) with a space or a tab
to prevent it from being expanded. The readline history facilities do
not attempt substitution on the strings '!=' and '!(', even when history
expansion is enabled.
The commands to control history expansion are:
'set history expansion on'
'set history expansion'
Enable history expansion. History expansion is off by default.
'set history expansion off'
Disable history expansion.
'show history'
'show history filename'
'show history save'
'show history size'
'show history expansion'
These commands display the state of the GDB history parameters.
'show history' by itself displays all four states.
'show commands'
Display the last ten commands in the command history.
'show commands N'
Print ten commands centered on command number N.
'show commands +'
Print ten commands just after the commands last printed.
Info Catalog
gdb: Editing
gdb: Controlling GDB
gdb: Screen Size