Append suffix to all files with a certain extension

Question

Write the command that will locate all files that have the suffix/extension of .py. For each file that is located, the command should append the suffix/extension of .backup to the file. So, if a file had the name one.py, its new name would be one.py.backup.

I tried

find . / -name "*.py" -type f -exec mv {} {}.backup \;

and it did not work

Answer 1

A shell-based solution could also work, since the task here is easy enough (simply appending a string fragment to a filename)

for file in *.py; do newname="$file.backup"; mv "$file" "$newname"; done

---

If it is possible that no such file exists, you would need to catch that case explicitly. Assuming bash, you could use the nullglob option:

shopt -s nullglob; for file in *.py; do newname="$file.backup"; mv "$file" "$newname"; done

or test explicitly if the file exists:

for file in *.py; do newname="$file.backup"; [ -f "$file" ] && mv "$file" "$newname"; done

---

If the files in question can also be in sub-directories, things get more complicated. With bash v4 onwards, you can use the globstar option:

shopt -s globstar; for file in **/*.py; do newname="$file.backup"; mv "$file" "$newname"; done

Again, you may have to combine with shopt -s nullglob to account for the case no such file exists.

Answer 2

I believe you can start doing something like:

> find PATH -name "*.py"

where you can change the PATH to the desired folder you want to look for... and them you could pipe the output with another command like mv using xargs.