sh/jshn.sh

   1 # functions for parsing and generating json
   2
   3 _json_get_var() {
   4         local ___dest="$1"
   5         local ___var="$2"
   6         eval "$___dest=\"\$${JSON_PREFIX}$___var\""
   7 }
   8
   9 _json_set_var() {
  10         local ___var="$1"
  11         local ___val="$2"
  12         eval "${JSON_PREFIX}$___var=\"\$___val\""
  13 }
  14
  15 _jshn_append() {
  16         local __var="$1"
  17         local __value="$2"
  18         local __sep="${3:- }"
  19         local __old_val
  20
  21         _json_get_var __old_val "$__var"
  22         __value="${__old_val:+$__old_val$__sep}$__value"
  23         _json_set_var "$__var" "$__value"
  24 }
  25
  26 _json_export() {
  27         local __var="${JSON_PREFIX}$1"
  28         local __val="$2"
  29
  30         export -- "$__var=$__val"
  31         _jshn_append "JSON_UNSET" "$__var"
  32 }
  33
  34 _json_add_key() {
  35         local table="$1"
  36         local var="$2"
  37         _jshn_append "KEYS_${table}" "$var"
  38 }
  39
  40 _get_var() {
  41         local __dest="$1"
  42         local __var="$2"
  43         eval "$__dest=\"\$$__var\""
  44 }
  45
  46 _set_var() {
  47         local __var="$1"
  48         local __val="$2"
  49         eval "$__var=\"\$__val\""
  50 }
  51
  52 _json_inc() {
  53         local _var="$1"
  54         local _dest="$2"
  55         local seq
  56
  57         _json_get_var seq "$_var"
  58         seq="$((${seq:-0} + 1))"
  59         _json_set_var "$_var" "$seq"
  60         [ -n "$dest" ] && _set_var "$_dest" "$seq"
  61 }
  62
  63 _json_stack_push() {
  64         local new_cur="$1"
  65         local cur
  66
  67         _json_get_var cur JSON_CUR
  68         _jshn_append JSON_STACK "$cur"
  69         _json_set_var JSON_CUR "$new_cur"
  70 }
  71
  72 _json_add_generic() {
  73         local type="$1"
  74         local var="$2"
  75         local val="$3"
  76         local cur="$4"
  77
  78         [ -n "$cur" ] || _json_get_var cur JSON_CUR
  79
  80         if [ "${cur%%[0-9]*}" = "JSON_ARRAY" ]; then
  81                 _json_inc "SEQ_$cur" var
  82         else
  83                 local name="${var//[^a-zA-Z0-9_]/_}"
  84                 [[ "$name" == "$var" ]] || _json_export "NAME_${cur}_${name}" "$var"
  85                 var="$name"
  86         fi
  87
  88         _json_export "${cur}_$var" "$val"
  89         _json_export "TYPE_${cur}_$var" "$type"
  90         _json_add_key "$cur" "$var"
  91 }
  92
  93 _json_add_table() {
  94         local name="$1"
  95         local type="$2"
  96         local itype="$3"
  97         local cur new_cur
  98
  99         _json_get_var cur JSON_CUR
 100         _json_inc JSON_SEQ seq
 101
 102         local table="JSON_$itype$seq"
 103         _json_export "UP_$table" "$cur"
 104         _json_export "KEYS_$table" ""
 105         [ "$TYPE" = "ARRAY" ] && _json_export "KEYS_$table" ""
 106         _json_stack_push "$table"
 107
 108         _json_get_var new_cur JSON_CUR
 109         _json_add_generic object "$1" "$new_cur" "$cur"
 110 }
 111
 112 _json_close_table() {
 113         local stack new_stack
 114
 115         _json_get_var stack JSON_STACK
 116         _json_set_var cur "${JSON_STACK##* }"
 117         new_stack="${stack% *}"
 118         [[ "$stack" == "$new_stack" ]] && new_stack=
 119         _json_set_var JSON_STACK "$new_stack"
 120 }
 121
 122 json_set_namespace() {
 123         local _new="$1"
 124         local _old="$2"
 125
 126         [ -n "$_old" ] && _set_var "$_old" "$JSON_PREFIX"
 127         JSON_PREFIX="$_new"
 128 }
 129
 130 json_cleanup() {
 131         local unset
 132
 133         _json_get_var unset JSON_UNSET
 134         [ -n "$unset" ] && eval "unset $unset"
 135
 136         unset \
 137                 ${JSON_PREFIX}JSON_SEQ \
 138                 ${JSON_PREFIX}JSON_STACK \
 139                 ${JSON_PREFIX}JSON_CUR \
 140                 ${JSON_PREFIX}JSON_UNSET \
 141                 ${JSON_PREFIX}KEYS_JSON_VAR \
 142                 ${JSON_PREFIX}TYPE_JSON_VAR
 143 }
 144
 145 json_init() {
 146         json_cleanup
 147         export -- \
 148                 ${JSON_PREFIX}JSON_SEQ=0 \
 149                 ${JSON_PREFIX}JSON_STACK= \
 150                 ${JSON_PREFIX}JSON_CUR="JSON_VAR" \
 151                 ${JSON_PREFIX}JSON_UNSET="" \
 152                 ${JSON_PREFIX}KEYS_JSON_VAR= \
 153                 ${JSON_PREFIX}TYPE_JSON_VAR=
 154 }
 155
 156 json_add_object() {
 157         _json_add_table "$1" object TABLE
 158 }
 159
 160 json_close_object() {
 161         _json_close_table
 162 }
 163
 164 json_add_array() {
 165         _json_add_table "$1" array ARRAY
 166 }
 167
 168 json_close_array() {
 169         _json_close_table
 170 }
 171
 172 json_add_string() {
 173         _json_add_generic string "$1" "$2"
 174 }
 175
 176 json_add_int() {
 177         _json_add_generic int "$1" "$2"
 178 }
 179
 180 json_add_boolean() {
 181         _json_add_generic boolean "$1" "$2"
 182 }
 183
 184 # functions read access to json variables
 185
 186 json_load() {
 187         eval `jshn -r "$1"`
 188 }
 189
 190 json_dump() {
 191         jshn "$@" ${JSON_PREFIX:+-p "$JSON_PREFIX"} -w
 192 }
 193
 194 json_get_type() {
 195         local dest="$1"
 196         local cur
 197
 198         _json_get_var cur JSON_CUR
 199         local var="${JSON_PREFIX}TYPE_${cur}_$2"
 200         eval "export -- \"$dest=\${$var}\"; [ -n \"\${$var+x}\" ]"
 201 }
 202
 203 json_get_var() {
 204         local __dest="$1"
 205         local __cur
 206
 207         _json_get_var __cur JSON_CUR
 208         local __var="${JSON_PREFIX}${__cur}_${2//[^a-zA-Z0-9_]/_}"
 209         eval "export -- \"$__dest=\${$__var}\"; [ -n \"\${$__var+x}\" ]"
 210 }
 211
 212 json_get_vars() {
 213         while [ "$#" -gt 0 ]; do
 214                 local _var="$1"; shift
 215                 json_get_var "$_var" "$_var"
 216         done
 217 }
 218
 219 json_select() {
 220         local target="$1"
 221         local type
 222
 223         [ -z "$1" ] && {
 224                 _json_set_var JSON_CUR "JSON_VAR"
 225                 return 0
 226         }
 227         [[ "$1" == ".." ]] && {
 228                 eval "JSON_CUR=\"\${UP_$JSON_CUR}\""
 229                 return 0
 230         }
 231         json_get_type type "$target"
 232         case "$type" in
 233                 object|array)
 234                         _json_get_var JSON_CUR "$target"
 235                 ;;
 236                 *)
 237                         echo "WARNING: Variable '$target' does not exist or is not an array/object"
 238                         return 1
 239                 ;;
 240         esac
 241 }