Split string on non alphanumeric characters using awk

Question

I'm trying to get the last substring before a non alphanumeric character. For eg.

1) beta gamma foo

2) beta gamma%foo

3) beta gamma|---foo

In all of the above examples I'm trying to get "foo" as it is the last substring after splitting on non-alphanumeric characters

So far I've tried

cat file* | awk -F'[^:alnum:]' '{print $NF;}' | less

but this doesn't give the expected results

Answer 1

Your POSIX regex is incorrect. Use this awk command:

awk -F '[^[:alnum:]]' '{print $NF}' file
foo
foo
foo