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(bashref.info)Bash History Facilities

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Bash History Facilities
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   When the `-o history' option to the `set' builtin is enabled (Note:
The Set Builtin), the shell provides access to the "command history",
the list of commands previously typed.  The value of the `HISTSIZE'
shell variable is used as the number of commands to save in a history
list.  The text of the last `$HISTSIZE' commands (default 500) is saved.
The shell stores each command in the history list prior to parameter
and variable expansion but after history expansion is performed,
subject to the values of the shell variables `HISTIGNORE' and
`HISTCONTROL'.

   When the shell starts up, the history is initialized from the file
named by the `HISTFILE' variable (default `~/.bash_history').  The file
named by the value of `HISTFILE' is truncated, if necessary, to contain
no more than the number of lines specified by the value of the
`HISTFILESIZE' variable.  When an interactive shell exits, the last
`$HISTSIZE' lines are copied from the history list to the file named by
`$HISTFILE'.  If the `histappend' shell option is set (Note: Bash
Builtins), the lines are appended to the history file, otherwise the
history file is overwritten.  If `HISTFILE' is unset, or if the history
file is unwritable, the history is not saved.  After saving the
history, the history file is truncated to contain no more than
`$HISTFILESIZE' lines.  If `HISTFILESIZE' is not set, no truncation is
performed.

   The builtin command `fc' may be used to list or edit and re-execute
a portion of the history list.  The `history' builtin may be used to
display or modify the history list and manipulate the history file.
When using command-line editing, search commands are available in each
editing mode that provide access to the history list (Note: Commands
For History).

   The shell allows control over which commands are saved on the history
list.  The `HISTCONTROL' and `HISTIGNORE' variables may be set to cause
the shell to save only a subset of the commands entered.  The `cmdhist'
shell option, if enabled, causes the shell to attempt to save each line
of a multi-line command in the same history entry, adding semicolons
where necessary to preserve syntactic correctness.  The `lithist' shell
option causes the shell to save the command with embedded newlines
instead of semicolons.  The `shopt' builtin is used to set these
options.  Note: Bash Builtins, for a description of `shopt'.