pad files to 8.3, fill with zeros

pad-internal-with-zero

#!/usr/bin/env bash

# Pad a range of file names with extra zeros
# AA012345.EXT = AA012345.EXT
# BB012345.EXT = BB012345.EXT
# ABC.EXT      = ABC00000.EXT
# ABCDE.EXT    = ABCDE0000.EXT

for orgfilename in *.EXT ; do
  #slice of EXT and add zeros
  newfilename="${orgfilename%%.*}00000000"

  #slice down to 8 chars and add EXT back on
  newfilename="${newfilename:0:8}.EXT"
  
  mv "${orgfilename}" "${newfilename}"
done