.. include:: ../header.txt

.. _history:

:command:`history`
===========================

.. index:: history, fc

:title:`Linux for Programmers and Users`, Sections 6.4.1

.. program:: history
.. describe:: history

   Bash tracks the commands that you type. You can use this to re-enter or
   edit a previous command. The history of past commands is normally kept
   in the ``~/.bash_history`` file.

SYNOPSIS
    :command:`history` [-c] [n]

    With options, the whole history file is displayed, the size of which is
    capped at 1000 lines.  The last *n* lines may also be displayed.

OPTIONS:

    .. option:: -c

       Clear the history

:command:`fc`
-------------

.. program:: fc
.. describe:: fc

   Display or edit and re-execute command from the history list
   that matches a command searched for.
   See ``help fc`` for more details.

SYNOPSIS
    :command:`fc` [-e ename] [command]

    :command:`fc` -s [pat=rep] [command]

    Execute the previous command if no command is specified.
    A useful alias is ``r='fc -s'``. The user can type ``r cmd`` to re-execute
    the last command beginning with *cmd* and typing ``r`` re-executes the last
    command while ``r foo=bar cmd`` re-executes *cmd* replacing *foo* for *bar*
    in the command.

OPTIONS:

    .. option:: -e ename

       Select which editor to use.  Default is FCEDIT, then EDITOR, then vi.
       
    .. option:: -s [pat=rep]

       Replace *pat* with *rep* before executing.

Command Line Editing
-----------------------

.. index:: command line editing

Previous entered commands may also be recalled and edited using text editing
commands before re-executing. The default editor for the BASH shell is
:ref:`emacs`, but it can be changed to :ref:`vi` by setting ``set -o vi`` in
the ``~/.bashrc`` file. 

In both emacs and vi modes, up and down arrows on the keyboard may be used
to find previous commands.  Left and right arrows may also be used to move
around on the command line.

In vi mode, press the *ESCAPE* key to enter vi's command mode. Then `j` and
`k` can move between commands and the within the command `h`, `l`, `b`, `w`,
and `e` are used to move *left*, *right*, *back word*, *next word*, and *end
of word*. To modify the command, use standard vi editing commands, such as
`cw` - *change word*, `3cw` - *change 3 words*, `dw` - *delete word*, 
`x` - *delete character*, `i` - *insert*, `a` - *append*, etc.