jsmnx

Extended version of the simple JSMN JSON parser.

This header provides a few useful additional functions in addition to those provided by jsmn.h. When using jsmnx, you should import this file instead of jsmn.h in your project.

We allow dependencies on the standard library in this file.

For completeness, this file also include prototypes for jsmn_init() and jsmn_parse(), even though they are also declared in jsmn.h.

See also

zserge/jsmn

Defines

JSMN_HEADER

JSMN_STRICT

JSMN_PARENT_LINKS

JSMN_CHUNK_SIZE

Chunck size when reallocating new chunks

Functions

void jsmn_init(jsmn_parser *parser)

Initializes a JSON parser.

Create JSON parser over an array of tokens

Creates a new parser based over a given buffer with an array of tokens available.

int jsmn_parse(jsmn_parser *parser, const char *js, const size_t len, jsmntok_t *tokens, const unsigned int num_tokens)

Run JSON parser.

It parses a JSON data string into and array of tokens, each describing a single JSON object.

Arguments

• parser: pointer to initialized parser

• js: the JSON input string

• len: length of js

• tokens: pointer to a preallocated buffer of JSMN tokens. May be NULL in order to return the number of tokens in the input.

• num_tokens: the size of tokens

Returns

On success, it returns the number of tokens actually used by the parser. On error, one of the following (negative) codes is returned:

• JSMN_ERROR_INVAL: bad token, JSON string is corrupted

• JSMN_ERROR_NOMEM: not enough tokens, JSON string is too large

• JSMN_ERROR_PART: JSON string is too short, expecting more JSON data

Run JSON parser. It parses a JSON data string into and array of tokens, each describing a single JSON object.

Parse JSON string and fill tokens.

int jsmn_parse_alloc(jsmn_parser *parser, const char *js, const size_t len, jsmntok_t **tokens_ptr, unsigned int *num_tokens_ptr)

Like jsmn_parse(), but realloc’s the buffer pointed to by tokens_ptr if it is too small. num_tokens_ptr should point to the number of allocated tokens or be zero if tokens_ptr is not pre-allocated.

Returns JSMN_ERROR_NOMEM on allocation error.

int jsmn_count(const jsmntok_t *t)

Returns number of sub-tokens contained in t or -1 on error.

const jsmntok_t *jsmn_item(const char *js, const jsmntok_t *t, const char *key)

Returns a pointer to the value of item key of JSMN object token t.

js is the JSON source.

Returns NULL on error.

const jsmntok_t *jsmn_element(const char *js, const jsmntok_t *t, int i)

Returns a pointer to the element i of JSMN array token t.

js is the JSON source.

Returns NULL on error.

const char *jsmn_strerror(int r)

Returns error message corresponding to return value from jsmn_parse().