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=
  14 }
  15
  16 json_add_generic() {
  17         local type="$1"
  18         local var="$2"
  19         local val="$3"
  20         local cur="${4:-$JSON_CUR}"
  21
  22         export -- "${cur}_$var=$val"
  23         export -- "TYPE_${cur}_$var=$type"
  24         jshn_append JSON_UNSET "${cur}_$var TYPE_${cur}_$var"
  25         jshn_append "KEYS_${cur}" "$var"
  26 }
  27
  28 json_add_table() {
  29         JSON_SEQ=$(($JSON_SEQ + 1))
  30         jshn_append JSON_STACK "$JSON_CUR"
  31         local table="JSON_TABLE$JSON_SEQ"
  32         export -- "UP_$table=$JSON_CUR"
  33         export -- "KEYS_$table="
  34         jshn_append JSON_UNSET "KEYS_$table UP_$table"
  35         JSON_CUR="$table"
  36 }
  37
  38 json_add_object() {
  39         local cur="$JSON_CUR"
  40         json_add_table
  41         json_add_generic object "$1" "$JSON_CUR" "$cur"
  42 }
  43
  44 json_close_object() {
  45         local oldstack="$JSON_STACK"
  46         JSON_CUR="${JSON_STACK##* }"
  47         JSON_STACK="${JSON_STACK% *}"
  48         [[ "$oldstack" == "$JSON_STACK" ]] && JSON_STACK=
  49 }
  50
  51 json_add_array() {
  52         local cur="$JSON_CUR"
  53         json_add_table
  54         json_add_generic array "$1" "$JSON_CUR" "$cur"
  55 }
  56
  57 json_close_array() {
  58         json_close_object
  59 }
  60
  61 json_add_string() {
  62         json_add_generic string "$1" "$2"
  63 }
  64
  65 json_add_int() {
  66         json_add_generic int "$1" "$2"
  67 }
  68
  69 json_add_boolean() {
  70         json_add_generic boolean "$1" "$2"
  71 }
  72
  73 # functions read access to json variables
  74
  75 json_load() {
  76         eval `jshn -r "$1"`
  77 }
  78
  79 json_dump() {
  80         jshn "$@" -w
  81 }
  82
  83 json_get_type() {
  84         local dest="$1"
  85         local var="$2"
  86         eval "export -- \"$dest=\${TYPE_${JSON_CUR}_$var}\""
  87 }
  88
  89 json_get_var() {
  90         local dest="$1"
  91         local var="$2"
  92         eval "export -- \"$dest=\${${JSON_CUR}_$var}\""
  93 }
  94
  95 json_select() {
  96         local target="$1"
  97         local type
  98
  99         [ -z "$1" ] && {
 100                 JSON_CUR="JSON_VAR"
 101                 return
 102         }
 103         [[ "$1" == ".." ]] && {
 104                 eval "JSON_CUR=\"\${UP_$JSON_CUR}\""
 105                 return;
 106         }
 107         json_get_type type "$target"
 108         case "$type" in
 109                 object|array)
 110                         json_get_var JSON_CUR "$target"
 111                 ;;
 112                 *)
 113                         echo "WARNING: Variable '$target' does not exist or is not an array/object"
 114                 ;;
 115         esac
 116 }