@cindex readline
@cindex command line editing
-@value{GDBN} reads its input commands via the @dfn{readline} interface. This
+@value{GDBN} reads its input commands via the @dfn{Readline} interface. This
@sc{gnu} library provides consistent behavior for programs which provide a
command line interface to the user. Advantages are @sc{gnu} Emacs-style
or @dfn{vi}-style inline editing of commands, @code{csh}-like history
Show whether command line editing is enabled.
@end table
+@xref{Command Line Editing}, for more details about the Readline
+interface. Users unfamiliar with @sc{gnu} Emacs or @code{vi} are
+encouraged to read that chapter.
+
@node History
@section Command history
+@cindex command history
@value{GDBN} 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 @value{GDBN} command
history facility.
+@value{GDBN} uses the @sc{gnu} History library, a part of the Readline
+package, to provide the history facility. @xref{Using History
+Interactively}, for the detailed description of the History library.
+
+Here is the description of @value{GDBN} commands related to command
+history.
+
@table @code
@cindex history substitution
@cindex history file
@code{HISTSIZE}, or to 256 if this variable is not set.
@end table
-@cindex history expansion
History expansion assigns special meaning to the character @kbd{!}.
-@ifset have-readline-appendices
-@xref{Event Designators}.
-@end ifset
+@xref{Event Designators}, for more details.
+@cindex history expansion, turn on/off
Since @kbd{!} is also the logical not operator in C, history expansion
is off by default. If you decide to enable history expansion with the
@code{set history expansion on} command, you may sometimes need to
@table @code
@item set history expansion on
@itemx set history expansion
-@cindex history expansion
+@kindex set history expansion
Enable history expansion. History expansion is off by default.
@item set history expansion off
Disable history expansion.
-The readline code comes with more complete documentation of
-editing and history expansion features. Users unfamiliar with @sc{gnu} Emacs
-or @code{vi} may wish to read it.
-@ifset have-readline-appendices
-@xref{Command Line Editing}.
-@end ifset
-
@c @group
@kindex show history
@item show history