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 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 -q         Quiet
  35 -s         Silent. Quiet and exit 0 on modified file.
  36 -v         Verbose
  37 -b         Keep backup file
  38 -h|--help  Help"
  39   local s diff name init file_dir exists verbose backup quiet silent
  40   file_dir="$(dirname "$file")"
  41   exists=true
  42   verbose=false
  43   backup=false
  44   quiet=false
  45   silent=false
  46
  47   case $1 in
  48     -b) backup=true; shift ;;
  49     -v) verbose=true; shift ;;
  50     -q) quiet=true; shift ;;
  51     -s) quiet=true; silent=true; shift ;;
  52     -h|--help) echo "$help"; return ;;
  53   esac
  54
  55   if (( $# == 2 )); then
  56     name=": $1"
  57     shift
  58   fi
  59
  60   local file="$1"
  61   local file_name="${file##*/}"
  62
  63   local comment
  64   comment="#_#_#"
  65
  66   # bind zone files use ; for comments yes, a little hacky detection.
  67   if [[ $file_name == db.* ]]; then
  68     comment=";;_;_;"
  69   fi
  70   local begin="$comment start delimiter of cedit section$name. do not modify. $comment"
  71   local end="$comment end delimiter of cedit section$name. do not modify. $comment"
  72
  73   if [[ ! -e $file_dir ]]; then
  74     if ! mkdir -p $file_dir; then
  75       s=sudo
  76       $s mkdir -p $file_dir || return 2
  77     fi
  78   fi
  79   if [[ ! -e $file ]]; then
  80     exists=false
  81     if ! $s touch $file; then
  82       s=sudo
  83       $s touch $file || return 2
  84     fi
  85   fi
  86
  87   [[ -w $file ]] || s=sudo
  88
  89
  90   local in_section=false
  91   if $exists; then
  92     local tailn=1
  93     local temp="$(mktemp -d)/$file_name"
  94     cp "$file" "$temp"
  95     cp /dev/null "$file"
  96     while IFS= read -r line; do
  97       tailn=$(( tailn + 1 ))
  98       if [[ $line == "$begin" ]]; then
  99         in_section=true;
 100         break
 101       fi
 102       printf '%s\n' "$line" >> $file
 103     done < "$temp"
 104   fi
 105
 106   IFS= read -d '' -n 1 -r init
 107   if [[ $init ]]; then
 108     $s tee -a "$file" >/dev/null <<<"$begin"
 109     printf '%s' "$init" | $s tee -a "$file" >/dev/null
 110     $s tee -a "$file" >/dev/null
 111     $s tee -a "$file" >/dev/null <<<"$end"
 112   fi
 113
 114   if $exists && $in_section; then
 115     while IFS= read -r line; do
 116       if [[ $line == "$begin" ]]; then
 117         in_section=true;
 118       fi
 119       if ! $in_section; then
 120         printf '%s\n' "$line" >> $file
 121       fi
 122       if [[ $line == $end ]]; then
 123         in_section=false;
 124       fi
 125     done < <(tail -n +$tailn "$temp")
 126   fi
 127
 128
 129   if ! $exists; then
 130     ret=1
 131     if $verbose; then
 132       echo "New file $file:"
 133       cat "$file"
 134     fi
 135   elif type -t diff &>/dev/null; then
 136     diff=$(diff -u "$temp" "$file")
 137     ret=$?
 138     if (( $ret )) && ! $quiet; then
 139       echo "backup of original at $temp"
 140       echo diff -u "$temp" "$file":
 141       echo "$diff"
 142       #elif $debug; then
 143       #  echo "No changes made to $file"
 144     fi
 145   else
 146     # for systems like openwrt which don't have diff
 147     diff=$(cmp "$temp" "$file")
 148     ret=$?
 149     if $verbose; then
 150       echo "$diff"
 151     fi
 152   fi
 153   if ! $backup && $exists; then
 154     rm -r "$temp"
 155   fi
 156   if $silent; then
 157     case $ret in
 158       0|1) return 0 ;;
 159       *) return $ret ;;
 160     esac
 161   else
 162     return $ret
 163   fi
 164 }
 165 cedit "$@"