batch rename multiple mp3's stripping leading digits

Question

Hi could anyone help me? I'm trying to strip leading digits from multiple mp3 files so 01 some_file.mp3 would become some_file.mp3.

If any one could show me how to do it with zmv that would be great, thanks.

Answer 1

This solution relies on Bash parameter expansion with substitution.

# Generate some dummy files for this demonstration
for i in {0..2}{0..9} ; do touch "$i some_file$i.mp3" ; done

# Rename, stripping two leading digits and a space
for i in [0-9][0-9]" "*.mp3 ; do mv "$i" "${i/[0-9][0-9] /}"; done

Answer 2

Use extended pattern matching:

shopt -s extglob
for F +([[:digit:]])*([[:blank:]])*.mp3; do
    mv -v -- "$F" "${F##+([[:digit:]])*([[:blank:]])}"
done

Or recursive:

shopt -s extglob

function remove_leading_digits {
    local A B
    for A; do
        B=${1##+([[:digit:]])*([[:blank:]])}
        [[ $A != "$B" ]] && mv -v -- "$A" "$B"
    done
}

readarray -t FILES < <(exec find your_dir -type f -regextype posix-egrep -regex '[[:digit:]]+[[:blank:]]*.mp3')
remove_leading_digits "${FILES[@]}"

You can save the function to work generally for a script:

#!/bin/ash

shopt -s extglob

function remove_leading_digits {
    local A B
    for A; do
        B=${1##+([[:digit:]])*([[:blank:]])}
        [[ $A != "$B" ]] && mv -v -- "$A" "$B"
    done
}

remove_leading_digits "$@"

And run it with

bash script.sh files

Like

shopt -s extglob
bash script.sh +([[:digit:]])*.mp3

Or just

bash script *.mp3  ## Still safe but slower.