fc (Unix)
fc
is a standard program on Unix and Unix-like operating systems that lists, edits and reexecutes commands previously entered to an interactive shell. fc is a builtin command in the Bash and Zsh shells and is an initialism for "fix command". It is particularly helpful for editing complex, multi-line commands. The editor can be specified by setting the EDITOR (changes the default editor) or the FCEDIT environment variable.
Developer(s) | Various open-source and commercial developers |
---|---|
Operating system | Unix, Unix-like |
Platform | Cross-platform |
Type | Command |
Examples
Flag -l
used to list previous command history, with example showing command ls
as item 1001 in the user's history.
$ fc -l
1001 ls
Flag -s
with this index would then recall the history command from 1001:
$ fc -s 1001
ls
Though more powerfully, -s
enables inline substitution.
$ ls floder
[user typo]
$ fc -s ^floder^folder^
ls folder
[Command revised and runs with correction]
Most powerfully, executing fc on its own edits the last command executed. Editor can be specified on command line (-e) or via environment variable FCEDIT. User is thus able to fully modify the last command executed via the editor, upon exiting will execute the resultant command.[1]
$ fc
[Change 'ls' to 'ls -la' in editor and exit]
ls -la
References
- "Fix history: Edit the last bash command". 5 January 2020.
External links
- : process the command history list – Shell and Utilities Reference, The Single UNIX Specification, Version 4 from The Open Group