sh/jshn.sh

   1 # functions for parsing and generating json
   2
   3 append() {
   4         local var="$1"
   5         local value="$2"
   6         local sep="${3:- }"
   7
   8         eval "export ${NO_EXPORT:+-n} -- \"$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=
  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         export ${NO_EXPORT:+-n} -- "${cur}_$var=$val"
  23         export ${NO_EXPORT:+-n} -- "TYPE_${cur}_$var=$type"
  24         append JSON_UNSET "${cur}_$var TYPE_${cur}_$var"
  25         append "KEYS_${cur}" "$var"
  26 }
  27
  28 json_add_table() {
  29         JSON_SEQ=$(($JSON_SEQ + 1))
  30         append JSON_STACK "$JSON_CUR"
  31         local table="JSON_TABLE$JSON_SEQ"
  32         export ${NO_EXPORT:+-n} -- "UP_$table=$JSON_CUR"
  33         JSON_CUR="$table"
  34 }
  35
  36 json_add_object() {
  37         local cur="$JSON_CUR"
  38         json_add_table
  39         json_add_generic object "$1" "$JSON_CUR" "$cur"
  40 }
  41
  42 json_close_object() {
  43         local oldstack="$JSON_STACK"
  44         export "KEYS_${JSON_CUR}"
  45         JSON_CUR="${JSON_STACK##* }"
  46         JSON_STACK="${JSON_STACK% *}"
  47         [[ "$oldstack" == "$JSON_STACK" ]] && JSON_STACK=
  48 }
  49
  50 json_add_array() {
  51         local cur="$JSON_CUR"
  52         json_add_table
  53         json_add_generic array "$1" "$JSON_CUR" "$cur"
  54 }
  55
  56 json_close_array() {
  57         json_close_object
  58 }
  59
  60 json_add_string() {
  61         json_add_generic string "$1" "$2"
  62 }
  63
  64 json_add_int() {
  65         json_add_generic int "$1" "$2"
  66 }
  67
  68 json_add_boolean() {
  69         json_add_generic boolean "$1" "$2"
  70 }
  71
  72 # functions read access to json variables
  73
  74 json_load() {
  75         eval `jshn -r "$1"`
  76 }
  77
  78 json_dump() {
  79         jshn -w
  80 }
  81
  82 json_get_type() {
  83         local dest="$1"
  84         local var="$2"
  85         eval "export ${NO_EXPORT:+-n} -- \"$dest=\${TYPE_${JSON_CUR}_$var}\""
  86 }
  87
  88 json_get_var() {
  89         local dest="$1"
  90         local var="$2"
  91         eval "export ${NO_EXPORT:+-n} -- \"$dest=\${${JSON_CUR}_$var}\""
  92 }
  93
  94 json_select() {
  95         local target="$1"
  96         local type
  97
  98         [ -z "$1" ] && {
  99                 JSON_CUR="JSON_VAR"
 100                 return
 101         }
 102         [[ "$1" == ".." ]] && {
 103                 eval "JSON_CUR=\"\${UP_$JSON_CUR}\""
 104                 return;
 105         }
 106         json_get_type type "$target"
 107         case "$type" in
 108                 object|array)
 109                         json_get_var JSON_CUR "$target"
 110                 ;;
 111                 *)
 112                         echo "WARNING: Variable '$target' does not exist or is not an array/object"
 113                 ;;
 114         esac
 115 }