iankelling.org Git - cedit/blob - cedit

   1 #!/bin/bash
   2 # I, Ian Kelling, follow the GNU license recommendations at
   3 # https://www.gnu.org/licenses/license-recommendations.en.html. They
   4 # recommend that small programs, < 300 lines, be licensed under the
   5 # Apache License 2.0. This file contains or is part of one or more small
   6 # programs. If a small program grows beyond 300 lines, I plan to switch
   7 # its license to GPL.
   8
   9 # Copyright 2024 Ian Kelling
  10
  11 # Licensed under the Apache License, Version 2.0 (the "License");
  12 # you may not use this file except in compliance with the License.
  13 # You may obtain a copy of the License at
  14
  15 #     http://www.apache.org/licenses/LICENSE-2.0
  16
  17 # Unless required by applicable law or agreed to in writing, software
  18 # distributed under the License is distributed on an "AS IS" BASIS,
  19 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  20 # See the License for the specific language governing permissions and
  21 # limitations under the License.
  22
  23 cedit() {
  24   local help="Usage: [-h|--help ] [-v] [SECTION_NAME] FILE
  25 Create/modify a comment-delimited section in a config file
  26
  27 Returns 1 if the file is modified by this command, 2 or higher
  28 for other problems.
  29
  30 The section is #comment delimited. Reads STDIN for the contents of the
  31 section. Without SECTION_NAME, it acts on a global unnamed
  32 section. cedit is short for config edit.
  33
  34 -b         Keep backup file
  35 -e         Exit 0 on modified file.
  36 -s         Silent. Quiet and exit 0 on modified file.
  37 -q         Quiet
  38 -v         Verbose
  39 -h|--help  Help"
  40   local s diff name init file_dir exists verbose backup quiet silent
  41   file_dir="$(dirname "$file")"
  42   exists=true
  43   verbose=false
  44   backup=false
  45   quiet=false
  46   silent=false
  47   exit_status=true
  48
  49   case $1 in
  50     -b) backup=true; shift ;;
  51     -e) exit_status=false; shift ;;
  52     -s) quiet=true; silent=true; exit_status=false; shift ;;
  53     -q) quiet=true; shift ;;
  54     -v) verbose=true; shift ;;
  55     -h|--help) echo "$help"; return ;;
  56   esac
  57
  58   if (( $# == 2 )); then
  59     name=": $1"
  60     shift
  61   fi
  62
  63   local file="$1"
  64   local file_name="${file##*/}"
  65
  66   local comment
  67   comment="#_#_#"
  68
  69   # bind zone files use ; for comments yes, a little hacky detection.
  70   if [[ $file_name == db.* ]]; then
  71     comment=";;_;_;"
  72   fi
  73   local begin="$comment start delimiter of cedit section$name. do not modify. $comment"
  74   local end="$comment end delimiter of cedit section$name. do not modify. $comment"
  75
  76   if [[ ! -e $file_dir ]]; then
  77     if ! mkdir -p $file_dir; then
  78       s=sudo
  79       $s mkdir -p $file_dir || return 2
  80     fi
  81   fi
  82   if [[ ! -e $file ]]; then
  83     exists=false
  84     if ! $s touch $file; then
  85       s=sudo
  86       $s touch $file || return 2
  87     fi
  88   fi
  89
  90   [[ -w $file ]] || s=sudo
  91
  92
  93   local in_section=false
  94   if $exists; then
  95     local tailn=1
  96     local temp="$(mktemp -d)/$file_name"
  97     cp "$file" "$temp"
  98     cp /dev/null "$file"
  99     while IFS= read -r line; do
 100       tailn=$(( tailn + 1 ))
 101       if [[ $line == "$begin" ]]; then
 102         in_section=true;
 103         break
 104       fi
 105       printf '%s\n' "$line" >> $file
 106     done < "$temp"
 107   fi
 108
 109   IFS= read -d '' -n 1 -r init
 110   if [[ $init ]]; then
 111     $s tee -a "$file" >/dev/null <<<"$begin"
 112     printf '%s' "$init" | $s tee -a "$file" >/dev/null
 113     $s tee -a "$file" >/dev/null
 114     $s tee -a "$file" >/dev/null <<<"$end"
 115   fi
 116
 117   if $exists && $in_section; then
 118     while IFS= read -r line; do
 119       if [[ $line == "$begin" ]]; then
 120         in_section=true;
 121       fi
 122       if ! $in_section; then
 123         printf '%s\n' "$line" >> $file
 124       fi
 125       if [[ $line == $end ]]; then
 126         in_section=false;
 127       fi
 128     done < <(tail -n +$tailn "$temp")
 129   fi
 130
 131
 132   if ! $exists; then
 133     ret=1
 134     if $verbose; then
 135       echo "New file $file:"
 136       cat "$file"
 137     fi
 138   elif type -t diff &>/dev/null; then
 139     diff=$(diff -u "$temp" "$file")
 140     ret=$?
 141     if (( $ret )) && ! $quiet; then
 142       echo "backup of original at $temp"
 143       echo diff -u "$temp" "$file":
 144       echo "$diff"
 145       #elif $debug; then
 146       #  echo "No changes made to $file"
 147     fi
 148   else
 149     # for systems like openwrt which don't have diff
 150     diff=$(cmp "$temp" "$file")
 151     ret=$?
 152     if $verbose; then
 153       echo "$diff"
 154     fi
 155   fi
 156   if ! $backup && $exists; then
 157     rm -r "$temp"
 158   fi
 159   if ! $exit_status; then
 160     case $ret in
 161       0|1) return 0 ;;
 162       *) return $ret ;;
 163     esac
 164   else
 165     return $ret
 166   fi
 167 }
 168 cedit "$@"