percent symbol in Bash, what’s it used for? [duplicate]

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