When running the following command:
rm -rf !(file1|file2)
all files except file1 and file2 are removed; as intended. When either placing this command in a bash script:
#!/bin/bash
rm -rf !(file1|file2)
or running it using bash -c:
bash -c "rm -rf !(file1|file2)"
I receive the following error:
syntax error ner unexpected token '('
I have tried setting the shell options using
shopt -s extglob
yeilding in:
bash -c "shopt -s extglob; rm -rf !(file1|file2)"
to enable glob according to: https://superuser.com/questions/231718/remove-all-files-except-for-a-few-from-a-folder-in-unix and some other questions as well.
Still it doesn't work, and I'm at loss.
First of all, for safety, let's do our testing with echo !(file1|file2) instead of rm -rf !(file1|file2).
Anyway, bash does some parsing of the entire command line before executing the shopt -s extglob command. When bash encounters the (, the extglob option isn't set yet. That's why you get the error.
Try this instead:
bash -O extglob -c 'echo !(file1|file2)'
In your script, you just need to turn on the option as a separate command line before relying on it:
#!/bin/bash
shopt -s extglob
echo !(file1|file2)
You can actually do this with the -c flag also:
bash -c 'shopt -s extglob
echo !(file1|file2)'
Or even like this:
bash -c $'shopt -s extglob\necho !(file1|file2)'