Question

I am trying to write a very simple bash script in order to add a file extension (.java) to a bunch of files that have no extension.

If they had an extensions (say .txt) I’d do this:

#!/bin/bash
for file in `*.txt`; 
do mv $file $file.java; 
done

My files, however, don’t have an extension. How do I make the loop? I tried *. with no luck.

Thank you.

Answer 1

#!/bin/bash
for file in *; do
  mv "$file" "$file".java; 
done

If you only want to move files that do not already have an extension, try:

#!/bin/sh
for file in *; do
  test "${file%.*}" = "$file" && mv "$file" "$file".java;
done

Note that all of the double-quotes above are superfluous if your filenames are reasonable.