1#!/bin/sh
2# Like mv $1 $2, but if the files are the same, just delete $1.
3# Status is zero if successful, nonzero otherwise.
4
5VERSION='2012-01-06 07:23'; # UTC
6# The definition above must lie within the first 8 lines in order
7# for the Emacs time-stamp write hook (at end) to update it.
8# If you change this file with Emacs, please let the write hook
9# do its job.  Otherwise, update this string manually.
10
11# Copyright (C) 2002-2014 Free Software Foundation, Inc.
12
13# This program is free software: you can redistribute it and/or modify
14# it under the terms of the GNU General Public License as published by
15# the Free Software Foundation, either version 3 of the License, or
16# (at your option) any later version.
17
18# This program is distributed in the hope that it will be useful,
19# but WITHOUT ANY WARRANTY; without even the implied warranty of
20# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21# GNU General Public License for more details.
22
23# You should have received a copy of the GNU General Public License
24# along with this program.  If not, see <http://www.gnu.org/licenses/>.
25
26usage="usage: $0 SOURCE DEST"
27
28help="$usage
29  or:  $0 OPTION
30If SOURCE is different than DEST, then move it to DEST; else remove SOURCE.
31
32  --help     display this help and exit
33  --version  output version information and exit
34
35The variable CMPPROG can be used to specify an alternative to 'cmp'.
36
37Report bugs to <bug-gnulib@gnu.org>."
38
39version=`expr "$VERSION" : '\([^ ]*\)'`
40version="move-if-change (gnulib) $version
41Copyright (C) 2011 Free Software Foundation, Inc.
42License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
43This is free software: you are free to change and redistribute it.
44There is NO WARRANTY, to the extent permitted by law."
45
46cmpprog=${CMPPROG-cmp}
47
48for arg
49do
50  case $arg in
51    --help | --hel | --he | --h)
52      exec echo "$help" ;;
53    --version | --versio | --versi | --vers | --ver | --ve | --v)
54      exec echo "$version" ;;
55    --)
56      shift
57      break ;;
58    -*)
59      echo "$0: invalid option: $arg" >&2
60      exit 1 ;;
61    *)
62      break ;;
63  esac
64done
65
66test $# -eq 2 || { echo "$0: $usage" >&2; exit 1; }
67
68if test -r "$2" && $cmpprog -- "$1" "$2" >/dev/null; then
69  rm -f -- "$1"
70else
71  if mv -f -- "$1" "$2"; then :; else
72    # Ignore failure due to a concurrent move-if-change.
73    test -r "$2" && $cmpprog -- "$1" "$2" >/dev/null && rm -f -- "$1"
74  fi
75fi
76
77## Local Variables:
78## eval: (add-hook 'write-file-hooks 'time-stamp)
79## time-stamp-start: "VERSION='"
80## time-stamp-format: "%:y-%02m-%02d %02H:%02M"
81## time-stamp-time-zone: "UTC"
82## time-stamp-end: "'; # UTC"
83## End:
84