iankelling.org Git - small-misc-bash/blob - isdiff

   1 #!/bin/bash
   2 # Copyright (C) 2014 Ian Kelling
   3
   4 # Licensed under the Apache License, Version 2.0 (the "License");
   5 # you may not use this file except in compliance with the License.
   6 # You may obtain a copy of the License at
   7
   8 #     http://www.apache.org/licenses/LICENSE-2.0
   9
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16 isdiff() {
  17     local help="Usage: isdiff [--help|-h] [-v] [-x] FILE1 FILE2
  18 Test if FILE1 and FILE2 have the same contents
  19
  20 Returns 0 for same, 1 for diff, 2 for error.
  21
  22 -v   verbose
  23 -r   use most reliable checksum available, ie. sha instead of md5"
  24
  25     local v x y reliable
  26     while true; do
  27         if [[ $1 == --help ]]  || [[ $1 == -[^-]* && $1 == *h* ]]; then
  28             echo "$help"
  29             return
  30         elif [[ $1 == -[^-]* && $1 == *v* ]]; then
  31             v=true
  32             shift
  33         elif [[ $1 == -[^-]* && $1 == *r* ]]; then
  34             reliable=true
  35             shift
  36         else
  37             break
  38         fi
  39     done
  40
  41     x=($(type -p sha512sum) $(type -p sha256sum) $(type -p sha1sum) $(type -p md5sum))
  42     if [[ $reliable ]]; then
  43         sumbinary=$x
  44     else
  45         sumbinary=${x[${#x[@]}-1]}
  46     fi
  47
  48     [[ $sumbinary ]] || {
  49         echo "Need 1 of sha512sum sha256sum sha1sum or md5sum for sum() function"
  50         return 1
  51     }
  52     if [[ $# != 2 ]]; then
  53         [[ $v ]] && echo Error: need 2 arguments.
  54         return 2
  55     fi
  56     if [[ $v ]]; then
  57         x=$($sumbinary < "$1" ) || return 2
  58         y=$($sumbinary < "$2" ) || return 2
  59     else
  60         { x=$($sumbinary < "$1" ) ;} 2>/dev/null || return 2
  61         { y=$($sumbinary < "$2" ) ;} 2>/dev/null || return 2
  62     fi
  63     if [[  $x == "$y" ]]; then
  64         return 1 # same
  65     else
  66         [[ $v ]] && echo "$1" "$2" different.
  67         return 0
  68     fi
  69 }
  70 isdiff "$@"