Question

I am trying to convert all files in a given directory with suffix “.foo” to files containing the same basename but with suffix modified to “.bar”. I am able to do this with a shell script and a for loop, but I want to write a one-liner that will achieve the same goal.

Objective:
  Input: *.foo
  Output: *.bar

This is what I have tried:

find . -name "*.foo" | xargs -I {} mv {} `basename {} ".foo"`.bar

This is close but incorrect. Results:
  Input: *.foo
  Output: *.foo.bar

Any ideas on why the given suffix is not being recognized by basename? The quotes around “.foo” are dispensable and the results are the same if they are omitted.

Answer 1

Although basename can work on file extensions, using the shell parameter expansion features is easier:

for file in *.foo; do mv "$file" "${file%.foo}.bar"; done

Your code with basename doesn’t work because the basename is only run once, and then xargs just sees {}.bar each time.