Pattern matching in bash doesn't seem to work in a script

[Paddy Landau]

I'm having a big problem with pattern matching in Bash.

Consider the following two lines, which I type into a terminal.

zn='2560x1024'
echo ${zn//+([[:digit:]])/} # Remove all digitsThe output is a single 'x', which is what I expect.

However, if I copy those exact lines into a script, as follows...

#!/bin/bash
zn='2560x1024'
echo ${zn//+([[:digit:]])/} # Remove all digitsThen the output from the script is '2560x1024'.

Why the difference?

[MadCow108]

extglob (extended pattern matching) is probably disabled in the subshell started by the script and is enabled in your regular shell:
enable it with:
shopt -s extglob

http://www.gnu.org/software/bash/manual/html_node/The-Shopt-Builtin.html

you can also use your regular shell by starting the script with source or .

[Paddy Landau]

+1 -- Thank you! I would never have worked that out myself.