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
15usage="Usage: newext [-th] <oldext> <newext> [filename ...]"
16
17phelp()
18{
19echo "$usage
20Rename all given files that end in oldext with newext replacing oldext.
21If no filenames are given, all files in the current directory that end
22in oldext are acted on (no filename is equivalent to '*').
23Options:
24-h: Print this help.
25-t: Test: No action is taken except to print the mv commands that would
26be executed if -t was not given."
27}
28
29while getopts "th" opt; do
30    case "$opt" in
31    t) echo=echo;;
32    h) phelp; exit 0;;
33    *) echo "$usage" 1>&2; exit 2;;
34   esac
35done
36
37shift $((OPTIND - 1))
38
39oldext=$1
40newext=$2
41
42case $# in 
43[01])	echo -e "$usage\nUse -h for help." 1>&2; exit 2;;
442)	shift ; shift; set -- *;;
45*)	shift ; shift;;
46esac
47
48found=
49
50for file
51do
52    case "$file" in
53    *$oldext) 
54	newname="${file%$oldext}$newext"
55	$echo mv "$file" "$newname"
56	found=true;;
57    esac
58done
59
60if [ -z "$found" ]; then
61    echo "No files ending in \"$oldext\"."
62    exit 1
63fi
64exit 0
65