percent symbol in Bash, what's it used for?

Question

I have a filename which ends with .zip and I wanted just the filename without zip. Here I found a trick in bash.

$f="05 - Means-End Analysis Videos.zip"
$echo "${f%*.zip}"
05 - Means-End Analysis Videos

What is happening here? How come %*.zip is removing my extension?

https://www.gnu.org/software/bash/manual/html_node/Shell-Parameter-Expansion.html Third section from bottom. — Jeff Y, Jan 22 '16 at 16:54
Have a look here [bash manipulating with strings percent sign](http://stackoverflow.com/questions/16444004/bash-manipulating-with-strings-percent-sign) — mauro, Jan 22 '16 at 16:57
Also, the `*` is superfluous (always matches nothing when used after single `%`). — Jeff Y, Jan 22 '16 at 17:00
note that another usage of the `%` character in bash is if a program such as `vim` is suspended with `ctrl-z`, then the `%vim` command resumes it, like `fg`. — xdavidliu, Nov 30 '19 at 23:27
As already noted in [another comment](https://stackoverflow.com/q/34951901#comment57635748_34951901), the `*` does not make much sense. The snippet `"${f%*.zip}"` means keep the content of `f`, but remove the last occurrence of `.zip`. * ~ * ~ * So in `"05 - Means-End Analysis Videos.zip"` simply cut out `.zip` to get `"05 - Means-End Analysis Videos"`. — Henke, Feb 08 '22 at 13:57

score 106 · Accepted Answer · answered Jan 22 '16 at 16:55

106

Delete the shortest match of string in $var from the beginning:

${var#string}

Delete the longest match of string in $var from the beginning:

${var##string}

Delete the shortest match of string in $var from the end:

${var%string}

Delete the longest match of string in $var from the end:

${var%%string}

Try:

var=foobarbar
echo "${var%b*r}"
> foobar
echo "${var%%b*r}"
> foo

answered Jan 22 '16 at 16:55

pfnuesel

4

This answer is fine, although any interested reader coming here may want to compare it with [this answer](https://stackoverflow.com/a/25536935) (which is slightly more elaborated I would say). – Henke Feb 08 '22 at 14:14

1 Answers1