Command line utility that saves me a lot of typing, but not very frequently. Probably only works on Linux.

compile with

ghc --make Renumber.hs -o renumber

and copy the executable into /usr/local/bin, or somewhere else in your $PATH

If you have a bunch of files whose names begin with two digit numeric identifiers, this program will renumber them in order. For example, if I have a directory containing

01. Artist1 - Song1.mp3
02. Artist2 - Song2.flac
03 - Song?
04slfjsalfj.pdf
not_numbered.txt

running

renumber --num 5

in the directory will result in

05. Artist1 - Song1.mp3
06. Artist2 - Song2.flac
07 - Song?
08slfjsalfj.pdf
not_numbered.txt

you can also do it to a directory you aren't currently in with --dir .