# Renumber files: Difference between revisions

Let's say you have a list of images named something_###.img with ### spanning 381-560, and you want to renumber them to be from 1 to 180.

## Bash/awk one-liner

 echo | awk '{for(i=1;i<181;i++) printf "mv something_%03d.img something_%03d.img\n",i+380,i;}' | bash -sf


will do it. Notice that "%03d" will make sure that numbers are padded with zeros (and if you need 4 digits total, just use %04d instead). Also, always pipe it to less first before piping to bash, just to make sure that you are not going to inadvertently delete something.

## Bash one-liner

 c=1 && for f in something_{381..560}.img ; do mv $f something_printf "%03d" "$c".img ; c=$(($c+1)) ; done


## Bash script

 #!/bin/bash
# set your first desired image number
c=1

# loop on the input file names.  the {X..Y} is called brace expansion.
for f in something_{381..560}.img ; do

# infinitely useful printf as you noted
mv $f something_printf "%03d" "$c".img

# increment the counter
c=$(($c+1))
done # loop ends


## Perl one-liner

 perl -e 'for(<*>) {rename $_,$1.($2-380).$3 if /(.+?)(\d+)(.img)\$/}'