sh/jshn.sh

   1 # functions for parsing and generating json
   2
   3 jshn_append() {
   4         local var="$1"
   5         local value="$2"
   6         local sep="${3:- }"
   7
   8         eval "export -- \"$var=\${$var:+\${$var}\${value:+\$sep}}\$value\""
   9 }
  10
  11 json_init() {
  12         [ -n "$JSON_UNSET" ] && eval "unset $JSON_UNSET"
  13         export -- JSON_SEQ=0 JSON_STACK= JSON_CUR="JSON_VAR" JSON_UNSET="" KEYS_JSON_VAR= TYPE_JSON_VAR=
  14 }
  15
  16 json_add_generic() {
  17         local type="$1"
  18         local var="$2"
  19         local val="$3"
  20         local cur="${4:-$JSON_CUR}"
  21
  22         if [ "${cur%%[0-9]*}" = "JSON_ARRAY" ]; then
  23                 eval "local aseq=\"\${SEQ_$cur}\""
  24                 var=$(( ${aseq:-0} + 1 ))
  25                 export -- "SEQ_$cur=$var"
  26         else
  27                 local name="$(echo -n "$var" | tr -C '[a-zA-Z_]' _)"
  28                 [[ "$name" == "$var" ]] || export -- "NAME_${cur}_${name}=$var"
  29                 var="$name"
  30         fi
  31
  32         export -- "${cur}_$var=$val"
  33         export -- "TYPE_${cur}_$var=$type"
  34         jshn_append JSON_UNSET "${cur}_$var TYPE_${cur}_$var"
  35         jshn_append "KEYS_${cur}" "$var"
  36 }
  37
  38 json_add_table() {
  39         local TYPE="$1"
  40         JSON_SEQ=$(($JSON_SEQ + 1))
  41         jshn_append JSON_STACK "$JSON_CUR"
  42         local table="JSON_$TYPE$JSON_SEQ"
  43         export -- "UP_$table=$JSON_CUR"
  44         export -- "KEYS_$table="
  45         jshn_append JSON_UNSET "KEYS_$table UP_$table"
  46         [ "$TYPE" = "ARRAY" ] && jshn_append JSON_UNSET "SEQ_$table"
  47         JSON_CUR="$table"
  48 }
  49
  50 json_add_object() {
  51         local cur="$JSON_CUR"
  52         json_add_table TABLE
  53         json_add_generic object "$1" "$JSON_CUR" "$cur"
  54 }
  55
  56 json_close_object() {
  57         local oldstack="$JSON_STACK"
  58         JSON_CUR="${JSON_STACK##* }"
  59         JSON_STACK="${JSON_STACK% *}"
  60         [[ "$oldstack" == "$JSON_STACK" ]] && JSON_STACK=
  61 }
  62
  63 json_add_array() {
  64         local cur="$JSON_CUR"
  65         json_add_table ARRAY
  66         json_add_generic array "$1" "$JSON_CUR" "$cur"
  67 }
  68
  69 json_close_array() {
  70         json_close_object
  71 }
  72
  73 json_add_string() {
  74         json_add_generic string "$1" "$2"
  75 }
  76
  77 json_add_int() {
  78         json_add_generic int "$1" "$2"
  79 }
  80
  81 json_add_boolean() {
  82         json_add_generic boolean "$1" "$2"
  83 }
  84
  85 # functions read access to json variables
  86
  87 json_load() {
  88         eval `jshn -r "$1"`
  89 }
  90
  91 json_dump() {
  92         jshn "$@" -w
  93 }
  94
  95 json_get_type() {
  96         local dest="$1"
  97         local var="$2"
  98         eval "export -- \"$dest=\${TYPE_${JSON_CUR}_$var}\""
  99 }
 100
 101 json_get_var() {
 102         local dest="$1"
 103         local var="$(echo -n "$2" | tr -C '[a-zA-Z_]' _)"
 104         eval "export -- \"$dest=\${${JSON_CUR}_$var}\""
 105 }
 106
 107 json_select() {
 108         local target="$1"
 109         local type
 110
 111         [ -z "$1" ] && {
 112                 JSON_CUR="JSON_VAR"
 113                 return
 114         }
 115         [[ "$1" == ".." ]] && {
 116                 eval "JSON_CUR=\"\${UP_$JSON_CUR}\""
 117                 return;
 118         }
 119         json_get_type type "$target"
 120         case "$type" in
 121                 object|array)
 122                         json_get_var JSON_CUR "$target"
 123                 ;;
 124                 *)
 125                         echo "WARNING: Variable '$target' does not exist or is not an array/object"
 126                 ;;
 127         esac
 128 }