Question

I cannot get composite patterns as described in http://www.gnu.org/software/bash/manual/bashref.html#Pattern-Matching to match inside my case statement:

i=33; case $i in *([A-Za-z0-9]) ) echo "alphanumeric";; * ) echo "bah";; esac;

I would expect the above script to display “alphanumeric” but instead it fails with:

bash: syntax error near unexpected token `('

Any idea what is wrong ?

Answer 1

Try turning on the extglob shell option like this:

shopt -s extglob

Then you can use the extended pattern matching operators:

i='33'; case $i in *([A-Za-z0-9]) ) echo "alphanumeric";; * ) echo "bah";; esac;

From the man page:

extglob – If set, the extended pattern matching features described above under Pathname Expansion are enabled.