How to rename a file by replacing specific letters in the file in linux

Question

I used a script that renamed my file eg 'echo webutil.olb | tr [A-Z] [a-z]' i wanted to rename it back to webutil.olb. How do i do this for many other files that i have

Answer 1

Debian rename allows you to specify a sed substitution pattern to apply against filenames in order to rename them.

Answer 2

Assuming that the files got renamed with the extra strings, this would probably help:

for file in echo*
do
    new="${file#* }"    # strip up to the first space (remove "echo ")
    new="${new% |*}"    # strip the space-pipe and after (remove " | tr ...")
    mv "$file" "$new"
done

This will rename, for example, a file named literally "echo webutil.olb | tr [A-Z] [a-z]" to be named "webutil.olb" and will work for other files similarly named. It expects the wanted names to be between a space and a space followed by a pipe.

Answer 3

For your example, tr left webutil.olb as it was.

In general, you can't do this, since you lose the information about case. For example, the filename "webutil.olb" might come from applying tr to "WebUtil.olb" or "WEBUTIL.olb".