examples/scripts.v2/newext

   1 #! /bin/bash
   2 #
   3 # original from:
   4 # newext: change filename extension
   5 # @(#) newext.sh 1.1 93/04/13
   6 # 90/06/06 john h. dubois iii (john@armory.com)
   7 # 90/11/14 changed ksh-specific code to hybrid: if running under Bourne,
   8 #          uses expr instead of ksh builtin ops.  Removed SYSV specific code.
   9 # 91/08/06 added -t option
  10 # 92/11/06 made earlier code actually work!
  11 # 93/04/13 If no filenames given, act on files in current dir
  12 #
  13 # conversion to bash v2 syntax by Chet Ramey
  14
  15 usage="Usage: newext [-th] <oldext> <newext> [filename ...]"
  16
  17 phelp()
  18 {
  19 echo "$usage
  20 Rename all given files that end in oldext with newext replacing oldext.
  21 If no filenames are given, all files in the current directory that end
  22 in oldext are acted on (no filename is equivalent to '*').
  23 Options:
  24 -h: Print this help.
  25 -t: Test: No action is taken except to print the mv commands that would
  26 be executed if -t was not given."
  27 }
  28
  29 while getopts "th" opt; do
  30     case "$opt" in
  31     t) echo=echo;;
  32     h) phelp; exit 0;;
  33     *) echo "$usage" 1>&2; exit 2;;
  34    esac
  35 done
  36
  37 shift $((OPTIND - 1))
  38
  39 oldext=$1
  40 newext=$2
  41
  42 case $# in
  43 [01])   echo -e "$usage\nUse -h for help." 1>&2; exit 2;;
  44 2)      shift ; shift; set -- *;;
  45 *)      shift ; shift;;
  46 esac
  47
  48 found=
  49
  50 for file
  51 do
  52     case "$file" in
  53     *$oldext)
  54         newname="${file%$oldext}$newext"
  55         $echo mv "$file" "$newname"
  56         found=true;;
  57     esac
  58 done
  59
  60 if [ -z "$found" ]; then
  61     echo "No files ending in \"$oldext\"."
  62     exit 1
  63 fi
  64 exit 0