Processes the command history list.
fc [ -r ] [ -e Editor ] [ First [ Last ] ]
fc -l [ -n ] [ -r ] [ First [ Last ] ]
fc -s [ Old= New ] [ First ]
The fc command displays the contents of your command history file or invokes an editor to modify and reexecutes commands previously entered in the shell.
The command history file lists commands by number. The first number in the list is selected arbitrarily. The relationship of a number to its command does not change except when the user logs in and no other process is accessing the list. In that case, the system resets the numbering to start the oldest retained command at 1.
If the numbers in the command history file reach a limit greater than the value of the HISTSIZE environment variable or 32767, whichever is greater, the shell wraps to 1. Despite this optional number wrapping, the fc command maintains the time-ordering sequence of the commands. For example, if three commands in sequence are given the numbers 32766, 32767, and 1 (wrapped), command 32767 is still considered previous to command 1.
The commands in the history file can be displayed using the -l (lowercase L) flag. When the -l flag is not specified and commands are edited using the -e Editor flag, the resulting lines are entered at the end of the history file and then reexecuted by the shell (the fc -e Editor command is not entered into the command history list). If the editor returns a non-zero exit status, this suppresses entry in the history file and command reexecution.
Any command-line variable assignments or redirection operators used with the fc command again invoke the previous command, suppressing standard error for both the fc command and the previous command. For example:
fc -s -- -1 2>/dev/null
|-e Editor||Edits commands using the specified editor. The Editor parameter should be a command name. The command is located using the PATH environment variable. The value in the FCEDIT environment variable is used as a default when the -e flag is not specified. If the FCEDIT environment variable is null or unset, the ed editor is used.|
|-l||(lowercase L) Lists the commands in your history file. No editor is invoked to modify them. The commands are written in the sequence indicated by the First and Last parameters, as affected by the -r flag, with each command preceded by the command number.|
|-n||Suppresses command numbers when used with the -l flag.|
|-r||Reverses the order of the commands listed (when used with the -l flag) or reverses the order of the commands edited (when the -l flag is not specified).|
|-s||Reexecutes a command without invoking an editor. If the First parameter is not also specified, the -s flag reexecutes the previous command.|
|First or Last||Selects the commands to list or edit. The number of previous
commands that can be accessed is determined by the value of the
HISTSIZE environment variable. The First and
Last parameters must have one of the following values:
When using the -s flag, omission of the First parameter causes the previous command to be used.
When the -s flag is not specified, the following rules apply:
fc -r 10 20 fc 30 40 fc 20 10 fc -r 40 30
fc -l fc 1 99
list and edit, respectively, all ten commands.
|Old=New||In commands to be reexecuted, replaces the fist occurrence of the old string with the new string.|
The following environment
variables affect the execution of the fc command:
|FCEDIT||When expanded by the shell, determines the default value for the -e editor variable. If the FCEDIT environment variable is null or is not set, the ed editor is the default.|
|HISTFILE||Determines the path name of the command history file. If the HISTFILE environment variable is not set, the shell may attempt to access or create the .sh_history file in the user's home directory.|
|HISTSIZE||Determines a decimal number representing the limit to the number of previous commands that are accessible. If this variable is not set, a default value of128 is used.|
The following exit values are
|0||Successful completion of the listing.|
|>0||An error occurred.|
Otherwise, the exit status is that of the commands executed by the fc command.
The command is executed when you finish editing.
fc -l -2
fc -s foo=bar cc
|/usr/bin/ksh||Contains the Korn shell fc built-in command.|
|/usr/bin/fc||Contains the fc command.|
The ksh command.