user/zeropad.sh

   1 #!/bin/bash
   2 # Desc: Zero-pad working dir files with initial digits for sorting
   3 # Usage: zeropad.sh
   4 # Version: 0.0.4
   5
   6 list_files() {
   7     # Desc: Lists working directory file basenames
   8     # Usage: list_files
   9     # Input: none
  10     # Output: stdout  a line-delimited list of file names
  11     find . -mindepth 1 -maxdepth 1 -type f -exec basename '{}' \; ;
  12 }; # list pwd file basenames
  13 main () {
  14     # Find the maximum number of leading digits in the filenames of working dir
  15     max_digits="$(list_files | sed -e 's/[^0-9].*//' | awk '{ if(length > L) L=length } END { print L }')";
  16     # declare -p max_digits; # debug
  17
  18     # Loop over the files and rename them
  19     while read -r file; do
  20         re='^[0-9]+';
  21         if [[ ! "$file" =~ $re ]]; then continue; fi;
  22
  23         # Extract the leading digits
  24         digits="$(echo "$file" | sed 's/\([0-9]*\).*/\1/')";
  25         # Zero-pad the digits
  26         padded_digits="$(printf "%0${max_digits}d" "$digits")";
  27         # Construct the new filename
  28         new_file="${padded_digits}${file#${digits}}";
  29         # Rename the file
  30         mv -n "$file" "$new_file"
  31         # declare -p file new_file; # debug
  32     done < <(list_files);
  33 }; # main program
  34
  35 main "$@";
  36
  37 # Author: Steven Baltakatei Sandoval
  38 # License: GPLv3+