Renaming files using regular expressions - Linux

Question

I have three files named

file1.txt
file2.txt
file3.txt

I am trying to rename them to

mynewfile-1.txt
mynewfile-2.txt
mynewfile-3.txt

How would I go about this using regular expressions?

Answer 1

Try this :

rename -n 's/^file/mynewfile-/' *.txt

or from comments :

rename -n 's/^file(\d+)/mynewfile-${1}-test/' *.txt
                   ___            ____
                    ^               ^
              capturing group       |
                               captured group

(remove -n switch when your tests are OK)

There are other tools with the same name which may or may not be able to do this, so be careful.

If you run the following command (GNU)

$ file "$(readlink -f "$(type -p rename)")"

and you have a result like

.../rename: Perl script, ASCII text executable

and not containing:

ELF

then this seems to be the right tool =)

If not, to make it the default (usually already the case) on Debian and derivative like Ubuntu :

$ sudo update-alternatives --set rename /path/to/rename

(replace /path/to/rename to the path of your perl's rename command.

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If you don't have this command, search your package manager to install it or do it manually (no deps)

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Last but not least, this tool was originally written by Larry Wall, the Perl's dad.