JSON.sh

   1 #!/usr/bin/env bash
   2
   3 throw () {
   4   echo "$*" >&2
   5   exit 1
   6 }
   7
   8 BRIEF=0
   9 LEAFONLY=0
  10 PRUNE=0
  11 NORMALIZE_SOLIDUS=0
  12
  13 usage() {
  14   echo
  15   echo "Usage: JSON.sh [-b] [-l] [-p] [-s] [-h]"
  16   echo
  17   echo "-p - Prune empty. Exclude fields with empty values."
  18   echo "-l - Leaf only. Only show leaf nodes, which stops data duplication."
  19   echo "-b - Brief. Combines 'Leaf only' and 'Prune empty' options."
  20   echo "-s - Remove escaping of the solidus symbol (stright slash)."
  21   echo "-h - This help text."
  22   echo
  23 }
  24
  25 parse_options() {
  26   set -- "$@"
  27   local ARGN=$#
  28   while [ "$ARGN" -ne 0 ]
  29   do
  30     case $1 in
  31       -h) usage
  32           exit 0
  33       ;;
  34       -b) BRIEF=1
  35           LEAFONLY=1
  36           PRUNE=1
  37       ;;
  38       -l) LEAFONLY=1
  39       ;;
  40       -p) PRUNE=1
  41       ;;
  42       -s) NORMALIZE_SOLIDUS=1
  43       ;;
  44       ?*) echo "ERROR: Unknown option."
  45           usage
  46           exit 0
  47       ;;
  48     esac
  49     shift 1
  50     ARGN=$((ARGN-1))
  51   done
  52 }
  53
  54 awk_egrep () {
  55   local pattern_string=$1
  56   gawk '{
  57     while ($0) {
  58       start=match($0, pattern);
  59       token=substr($0, start, RLENGTH);
  60       print token;
  61       $0=substr($0, start+RLENGTH);
  62     }
  63   }' pattern="$pattern_string"
  64 }
  65
  66 tokenize () {
  67   local GREP
  68   local ESCAPE
  69   local CHAR
  70
  71   if echo "test string" | egrep -ao --color=never "test" &>/dev/null
  72   then
  73     GREP='egrep -ao --color=never'
  74   else
  75     GREP='egrep -ao'
  76   fi
  77
  78   if echo "test string" | egrep -o "test" &>/dev/null
  79   then
  80     ESCAPE='(\\[^u[:cntrl:]]|\\u[0-9a-fA-F]{4})'
  81     CHAR='[^[:cntrl:]"\\]'
  82   else
  83     GREP=awk_egrep
  84     ESCAPE='(\\\\[^u[:cntrl:]]|\\u[0-9a-fA-F]{4})'
  85     CHAR='[^[:cntrl:]"\\\\]'
  86   fi
  87
  88   local STRING="\"$CHAR*($ESCAPE$CHAR*)*\""
  89   local NUMBER='-?(0|[1-9][0-9]*)([.][0-9]*)?([eE][+-]?[0-9]*)?'
  90   local KEYWORD='null|false|true'
  91   local SPACE='[[:space:]]+'
  92
  93   $GREP "$STRING|$NUMBER|$KEYWORD|$SPACE|." | egrep -v "^$SPACE$"
  94 }
  95
  96 parse_array () {
  97   local index=0
  98   local ary=''
  99   read -r token
 100   case "$token" in
 101     ']') ;;
 102     *)
 103       while :
 104       do
 105         parse_value "$1" "$index"
 106         index=$((index+1))
 107         ary="$ary""$value"
 108         read -r token
 109         case "$token" in
 110           ']') break ;;
 111           ',') ary="$ary," ;;
 112           *) throw "EXPECTED , or ] GOT ${token:-EOF}" ;;
 113         esac
 114         read -r token
 115       done
 116       ;;
 117   esac
 118   [ "$BRIEF" -eq 0 ] && value=$(printf '[%s]' "$ary") || value=
 119   :
 120 }
 121
 122 parse_object () {
 123   local key
 124   local obj=''
 125   read -r token
 126   case "$token" in
 127     '}') ;;
 128     *)
 129       while :
 130       do
 131         case "$token" in
 132           '"'*'"') key="$token" ;;
 133           *) throw "EXPECTED string GOT ${token:-EOF}" ;;
 134         esac
 135         read -r token
 136         case "$token" in
 137           ':') ;;
 138           *) throw "EXPECTED : GOT ${token:-EOF}" ;;
 139         esac
 140         read -r token
 141         parse_value "$1" "$key"
 142         obj="$obj$key:$value"
 143         read -r token
 144         case "$token" in
 145           '}') break ;;
 146           ',') obj="$obj," ;;
 147           *) throw "EXPECTED , or } GOT ${token:-EOF}" ;;
 148         esac
 149         read -r token
 150       done
 151     ;;
 152   esac
 153   [ "$BRIEF" -eq 0 ] && value=$(printf '{%s}' "$obj") || value=
 154   :
 155 }
 156
 157 parse_value () {
 158   local jpath="${1:+$1.}$2" isleaf=0 isempty=0 print=0
 159   case "$token" in
 160     '{') parse_object "$jpath" ;;
 161     '[') parse_array  "$jpath" ;;
 162     # At this point, the only valid single-character tokens are digits.
 163     ''|[!0-9]) throw "EXPECTED value GOT ${token:-EOF}" ;;
 164     *) value=$token
 165        # if asked, replace solidus ("\/") in json strings with normalized value: "/"
 166        [ "$NORMALIZE_SOLIDUS" -eq 1 ] && value=${value//\\\//\/}
 167        isleaf=1
 168        [ "$value" = '""' ] && isempty=1
 169        ;;
 170   esac
 171   [ "$value" = '' ] && return
 172   [ "$LEAFONLY" -eq 0 ] && [ "$PRUNE" -eq 0 ] && print=1
 173   [ "$LEAFONLY" -eq 1 ] && [ "$isleaf" -eq 1 ] && [ $PRUNE -eq 0 ] && print=1
 174   [ "$LEAFONLY" -eq 0 ] && [ "$PRUNE" -eq 1 ] && [ "$isempty" -eq 0 ] && print=1
 175   [ "$LEAFONLY" -eq 1 ] && [ "$isleaf" -eq 1 ] && \
 176     [ $PRUNE -eq 1 ] && [ $isempty -eq 0 ] && print=1
 177   [ "$print" -eq 1 ] && printf "%s\t%s\n" "${jpath//\"/}" "$value"
 178   :
 179 }
 180
 181 parse () {
 182   read -r token
 183   parse_value
 184   read -r token
 185   case "$token" in
 186     '') ;;
 187     *) throw "EXPECTED EOF GOT $token" ;;
 188   esac
 189 }
 190
 191 if ([ "$0" = "$BASH_SOURCE" ] || ! [ -n "$BASH_SOURCE" ]);
 192 then
 193   parse_options "$@"
 194   tokenize | parse
 195 fi
 196
 197 #The MIT License
 198 #
 199 #Copyright (c) 2011 Dominic Tarr
 200 #
 201 #Permission is hereby granted, free of charge,
 202 #to any person obtaining a copy of this software and
 203 #associated documentation files (the "Software"), to
 204 #deal in the Software without restriction, including
 205 #without limitation the rights to use, copy, modify,
 206 #merge, publish, distribute, sublicense, and/or sell
 207 #copies of the Software, and to permit persons to whom
 208 #the Software is furnished to do so,
 209 #subject to the following conditions:
 210 #
 211 #The above copyright notice and this permission notice
 212 #shall be included in all copies or substantial portions of the Software.
 213 #
 214 #THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 215 #EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 216 #OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 217 #IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
 218 #ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 219 #TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 220 #SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.