String replacement in filenames in linux

Question

I have a tonne of files called File30_i.txt for i=1, 2, 3, 4, 5... Is there an easy way to quickly rename then File20_i.txt for example?

Answer 1

There is a tool for that called rename:

rename 's/File30/File20/' *.txt

For a preview run with -n:

rename -n 's/File30/File20/' *.txt

Answer 2

My preferred way would be to use sed to generate a script for it, for example:

ls -1|sed 's/File30_\([^.]*\).txt/mv & File20_\1.txt/'|bash

This should rename as per the filenames you gave in the question. To preview the commands, you can do:

ls -1|sed 's/File30_\([^.]*\).txt/mv & File20_\1.txt/'

Answer 3

renamer works on Windows, Mac and Linux:

$ renamer --find Find30 --replace Find20 *.txt