Merge pull request #1 from danog/master

pulling

api/JSON.sh

@@ -0,0 +1,204 @@
+#!/usr/bin/env bash
+
+throw () {
+  echo "$*" >&2
+  exit 1
+}
+
+BRIEF=0
+LEAFONLY=0
+PRUNE=0
+NO_HEAD=0
+NORMALIZE_SOLIDUS=0
+
+usage() {
+  echo
+  echo "Usage: JSON.sh [-b] [-l] [-p] [-s] [-h]"
+  echo
+  echo "-p - Prune empty. Exclude fields with empty values."
+  echo "-l - Leaf only. Only show leaf nodes, which stops data duplication."
+  echo "-b - Brief. Combines 'Leaf only' and 'Prune empty' options."
+  echo "-n - No-head. Do not show nodes that have no path (lines that start with [])."
+  echo "-s - Remove escaping of the solidus symbol (stright slash)."
+  echo "-h - This help text."
+  echo
+}
+
+parse_options() {
+  set -- "$@"
+  local ARGN=$#
+  while [ "$ARGN" -ne 0 ]
+  do
+    case $1 in
+      -h) usage
+          exit 0
+      ;;
+      -b) BRIEF=1
+          LEAFONLY=1
+          PRUNE=1
+      ;;
+      -l) LEAFONLY=1
+      ;;
+      -p) PRUNE=1
+      ;;
+      -n) NO_HEAD=1
+      ;;
+      -s) NORMALIZE_SOLIDUS=1
+      ;;
+      ?*) echo "ERROR: Unknown option."
+          usage
+          exit 0
+      ;;
+    esac
+    shift 1
+    ARGN=$((ARGN-1))
+  done
+}
+
+awk_egrep () {
+  local pattern_string=$1
+
+  gawk '{
+    while ($0) {
+      start=match($0, pattern);
+      token=substr($0, start, RLENGTH);
+      print token;
+      $0=substr($0, start+RLENGTH);
+    }
+  }' pattern="$pattern_string"
+}
+
+tokenize () {
+  local GREP
+  local ESCAPE
+  local CHAR
+
+  if echo "test string" | egrep -ao --color=never "test" &>/dev/null
+  then
+    GREP='egrep -ao --color=never'
+  else
+    GREP='egrep -ao'
+  fi
+
+  if echo "test string" | egrep -o "test" &>/dev/null
+  then
+    ESCAPE='(\\[^u[:cntrl:]]|\\u[0-9a-fA-F]{4})'
+    CHAR='[^[:cntrl:]"\\]'
+  else
+    GREP=awk_egrep
+    ESCAPE='(\\\\[^u[:cntrl:]]|\\u[0-9a-fA-F]{4})'
+    CHAR='[^[:cntrl:]"\\\\]'
+  fi
+
+  local STRING="\"$CHAR*($ESCAPE$CHAR*)*\""
+  local NUMBER='-?(0|[1-9][0-9]*)([.][0-9]*)?([eE][+-]?[0-9]*)?'
+  local KEYWORD='null|false|true'
+  local SPACE='[[:space:]]+'
+
+  $GREP "$STRING|$NUMBER|$KEYWORD|$SPACE|." | egrep -v "^$SPACE$"
+}
+
+parse_array () {
+  local index=0
+  local ary=''
+  read -r token
+  case "$token" in
+    ']') ;;
+    *)
+      while :
+      do
+        parse_value "$1" "$index"
+        index=$((index+1))
+        ary="$ary""$value" 
+        read -r token
+        case "$token" in
+          ']') break ;;
+          ',') ary="$ary," ;;
+          *) throw "EXPECTED , or ] GOT ${token:-EOF}" ;;
+        esac
+        read -r token
+      done
+      ;;
+  esac
+  [ "$BRIEF" -eq 0 ] && value=$(printf '[%s]' "$ary") || value=
+  :
+}
+
+parse_object () {
+  local key
+  local obj=''
+  read -r token
+  case "$token" in
+    '}') ;;
+    *)
+      while :
+      do
+        case "$token" in
+          '"'*'"') key=$token ;;
+          *) throw "EXPECTED string GOT ${token:-EOF}" ;;
+        esac
+        read -r token
+        case "$token" in
+          ':') ;;
+          *) throw "EXPECTED : GOT ${token:-EOF}" ;;
+        esac
+        read -r token
+        parse_value "$1" "$key"
+        obj="$obj$key:$value"        
+        read -r token
+        case "$token" in
+          '}') break ;;
+          ',') obj="$obj," ;;
+          *) throw "EXPECTED , or } GOT ${token:-EOF}" ;;
+        esac
+        read -r token
+      done
+    ;;
+  esac
+  [ "$BRIEF" -eq 0 ] && value=$(printf '{%s}' "$obj") || value=
+  :
+}
+
+parse_value () {
+  local jpath="${1:+$1,}$2" isleaf=0 isempty=0 print=0
+  case "$token" in
+    '{') parse_object "$jpath" ;;
+    '[') parse_array  "$jpath" ;;
+    # At this point, the only valid single-character tokens are digits.
+    ''|[!0-9]) throw "EXPECTED value GOT ${token:-EOF}" ;;
+    *) value=$token
+       # if asked, replace solidus ("\/") in json strings with normalized value: "/"
+       [ "$NORMALIZE_SOLIDUS" -eq 1 ] && value=${value//\\\//\/}
+       isleaf=1
+       [ "$value" = '""' ] && isempty=1
+       ;;
+  esac
+  [ "$value" = '' ] && return
+  [ "$NO_HEAD" -eq 1 ] && [ -z "$jpath" ] && return
+
+  [ "$LEAFONLY" -eq 0 ] && [ "$PRUNE" -eq 0 ] && print=1
+  [ "$LEAFONLY" -eq 1 ] && [ "$isleaf" -eq 1 ] && [ $PRUNE -eq 0 ] && print=1
+  [ "$LEAFONLY" -eq 0 ] && [ "$PRUNE" -eq 1 ] && [ "$isempty" -eq 0 ] && print=1
+  [ "$LEAFONLY" -eq 1 ] && [ "$isleaf" -eq 1 ] && \
+    [ $PRUNE -eq 1 ] && [ $isempty -eq 0 ] && print=1
+  [ "$print" -eq 1 ] && printf "[%s]\t%s\n" "$jpath" "$value"
+  :
+}
+
+parse () {
+  read -r token
+  parse_value
+  read -r token
+  case "$token" in
+    '') ;;
+    *) throw "EXPECTED EOF GOT $token" ;;
+  esac
+}
+
+if ([ "$0" = "$BASH_SOURCE" ] || ! [ -n "$BASH_SOURCE" ]);
+then
+  parse_options "$@"
+  tokenize | parse
+fi
+
+# vi: expandtab sw=2 ts=2