Rename all files found by extension in for loop

Question

My task is to write a script that searches for all files without .old extension within given directory and renames files to this format: filename.old. I've tried this script:

#!/bin/bash
for i in $(grep "\.[^old]&" $1 | ls)
do
 mv "$1/$i" "$1/$i.old"
done

but it gives a wrong output.

• These files were in my directory: f1, f2.old, f3, f4.old.
• Expected output: f1.old, f2.old, f3.old, f4.old.
• My output (1st launch): f1.old, f2.old.old, f3.old, f4.old.old. Each time when I launch script it keeps adding .old extension, so it becomes like this:
• My output (2nd launch): f1.old.old, f2.old.old.old, f3.old.old, f4.old.old.old.

How can this be improved?

Answer 1

You could use a one-liner like so:

find . -mindepth 1 ! -name '*.old' -exec mv {} {}.old \;

Example on GNU/Linux (Ubuntu 14.04 LTS):

mkdir so
cd so
touch f1 f2.old f3 f4.old
find . -mindepth 1 ! -name '*.old' -exec mv {} {}.old \;
ls

Result:

f1.old f2.old f3.old f4.old

Explanation:

• find . means find in current directory
• -mindepth 1 will return the files without returning the current directory . (see https://askubuntu.com/questions/153770/how-to-have-find-not-return-the-current-directory)
• ! -name '*.old' will skip any files ending with .old
• -exec mv executes the mv (move) command on the returned files denoted with {} and adds an extension to it with {}.old meaning whatever-filename-was-returned.old

You can modify your script like so to get similar result:

test.sh.old

#!/bin/bash
for i in $(find . -mindepth 1 ! -name '*.old'); do
        mv "$i" "$i.old"
done

Execute with bash test.sh.old to get similar results.

You may have to try some test cases to see if the one-liner and the modified test.sh.old file passes those test conditions. I tested it with the sample you provided and this returns the desired results.