JSON(2)                                                   JSON(2)





     NAME
          jsonparse, jsonfree, jsonbyname, jsonstr - JSON parser

     SYNOPSIS
          #include <u.h>
          #include <libc.h>
          #include <json.h>

          enum {
                 JSONNull,
                 JSONBool,
                 JSONNumber,
                 JSONString,
                 JSONArray,
                 JSONObject,
          };

          typedef struct JSONEl JSONEl;
          struct JSONEl {
                 char *name;
                 JSON *val;
                 JSONEl *next;
          };

          typedef struct JSON JSON;
          struct JSON
          {
                 int t;
                 union {
                        double n;
                        char *s;
                        JSONEl *first;
                 };
          };

          JSON*  jsonparse(char *s);
          void   jsonfree(JSON *j);
          JSON*  jsonbyname(JSON *j, char *s);
          char*  jsonstr(JSON *j);
          int    JSONfmt(Fmt *f)
          void   JSONfmtinstall(void);

     DESCRIPTION
          The JSON structure represents a variant json value. The
          variant type is stored in the t member of the structure.
          String values use s, booleans and numbers use the n members
          in the structure.  Arrays and objects (dictionaries) are
          represented by a singly-linked list of JSONEl structures
          referred to from the first pointer in the JSON structure.
          Each JSONEl has a val pointer to the associated value and a










     JSON(2)                                                   JSON(2)



          next pointer to the next element in the array or object.
          Dictionary objects have the name member set to the key of
          the association.

          A json object is parsed by calling jsonparse with a UTF-8
          string of the json encoded data. On success, a non-nil
          pointer to a newly allocated JSON structure is returned.  To
          free the parsed objects, jsonfree has to be called.

          The jsonbyname function returns the associated value of a
          dictionary item.

          The function jsonstr returns the string value of a json
          object or nil for any other object type.

          JSONfmt is a print(2) formatting routine that prints a
          well-formatted JSON structure.  It can be installed by hand
          but JSONfmtinstall installs it under the standard format
          character J. The header <json.h> contains a #pragma state-
          ment so the compiler can type-check uses of %J in print(2)
          format strings.

     SOURCE
          /sys/src/libjson

     DIAGNOSTICS
          The functions jsonparse, jsonbyname and jsonstr return nil
          on error and set an error string (see errstr(2)).