wsjson.h File Reference

#include "ws_symbol_export.h"
#include <inttypes.h>
#include <stdbool.h>
#include "jsmn.h"

Go to the source code of this file.

Functions
WS_DLL_PUBLIC bool	json_validate (const uint8_t *buf, const size_t len)
WS_DLL_PUBLIC int	json_parse (const char *buf, jsmntok_t *tokens, unsigned int max_tokens)
WS_DLL_PUBLIC int	json_parse_len (const char *buf, size_t len, jsmntok_t *tokens, unsigned int max_tokens)
WS_DLL_PUBLIC jsmntok_t *	json_get_object (const char *buf, jsmntok_t *parent, const char *name)
WS_DLL_PUBLIC jsmntok_t *	json_get_array (const char *buf, jsmntok_t *parent, const char *name)
WS_DLL_PUBLIC int	json_get_array_len (jsmntok_t *array)
WS_DLL_PUBLIC jsmntok_t *	json_get_array_index (jsmntok_t *parent, int idx)
WS_DLL_PUBLIC char *	json_get_string (char *buf, jsmntok_t *parent, const char *name)
WS_DLL_PUBLIC bool	json_get_double (char *buf, jsmntok_t *parent, const char *name, double *val)
WS_DLL_PUBLIC bool	json_get_boolean (char *buf, jsmntok_t *parent, const char *name, bool *val)
WS_DLL_PUBLIC bool	json_decode_string_inplace (char *text)

Detailed Description

JSON parsing functions.

Copyright 2016, Dario Lombardo

Wireshark - Network traffic analyzer By Gerald Combs geral.nosp@m.d@wi.nosp@m.resha.nosp@m.rk.o.nosp@m.rg Copyright 1998 Gerald Combs

SPDX-License-Identifier: GPL-2.0-or-later

Function Documentation

json_decode_string_inplace()

WS_DLL_PUBLIC bool json_decode_string_inplace

(

char *

text

)

Decode the contents of a JSON string value by overwriting the input data. Returns true on success and false if invalid characters were encountered.

json_get_array()

WS_DLL_PUBLIC jsmntok_t * json_get_array	(	const char *	buf,
		jsmntok_t *	parent,
		const char *	name
	)

Get the pointer to an array belonging to parent object and named as the name variable. Returns NULL if not found.

json_get_array_index()

WS_DLL_PUBLIC jsmntok_t * json_get_array_index	(	jsmntok_t *	parent,
		int	idx
	)

Get the pointer to idx element of an array. Returns NULL if not found.

json_get_array_len()

WS_DLL_PUBLIC int json_get_array_len

(

jsmntok_t *

array

)

Get the number of elements of an array. Returns -1 if the JSON objecct is not an array.

json_get_boolean()

WS_DLL_PUBLIC bool json_get_boolean	(	char *	buf,
		jsmntok_t *	parent,
		const char *	name,
		bool *	val
	)

Get the value of a boolean belonging to parent object and named as the name variable. Returns false if not found. (Not the same as the boolean present but false.)

json_get_double()

WS_DLL_PUBLIC bool json_get_double	(	char *	buf,
		jsmntok_t *	parent,
		const char *	name,
		double *	val
	)

Get the value of a number object belonging to parent object and named as the name variable. Returns false if not found. Caution: it modifies input buffer. Scientific notation not supported yet.

json_get_object()

WS_DLL_PUBLIC jsmntok_t * json_get_object	(	const char *	buf,
		jsmntok_t *	parent,
		const char *	name
	)

Get the pointer to an object belonging to parent object and named as the name variable. Returns NULL if not found.

json_get_string()

WS_DLL_PUBLIC char * json_get_string	(	char *	buf,
		jsmntok_t *	parent,
		const char *	name
	)

Get the unescaped value of a string object belonging to parent object and named as the name variable. Returns NULL if not found. Caution: it modifies input buffer.

json_parse()

WS_DLL_PUBLIC int json_parse	(	const char *	buf,
		jsmntok_t *	tokens,
		unsigned int	max_tokens
	)

Parse a JSON string and put the location of tokens into the tokens array.

Parameters

buf	- A null-terminated string containing JSON.
tokens	- An array of tokens. Can be NULL, to validate only.
max_tokens	- The length of tokens. Ignored if tokens is NULL.

Returns

The number of tokens needed, or a jsmnerr (which are negative).

Note

This calls strlen() and requires that buf be a null-terminated string. This can be called with NULL tokens in order to determine the number of tokens necessary.

json_parse_len()

WS_DLL_PUBLIC int json_parse_len	(	const char *	buf,
		size_t	len,
		jsmntok_t *	tokens,
		unsigned int	max_tokens
	)

Parse a JSON buffer and put the location of tokens into the tokens array.

Parameters

buf	- A buffer containing JSON, not necessarily null-terminated.
len	- The length of the JSON data in the buffer.
tokens	- An array of tokens. Can be NULL, to validate only.
max_tokens	- The length of tokens. Ignored if tokens is NULL.

Returns

The number of tokens needed, or a jsmnerr (which are negative).

Note

This still stops parsing after the first '\0' byte, if any. It's useful if a buffer is not null-terminated or if the length is already known. This can be called with NULL tokens in order to determine the number of tokens necessary.

json_validate()

WS_DLL_PUBLIC bool json_validate	(	const uint8_t *	buf,
		const size_t	len
	)

Check if a buffer is JSON and returns true if it is.

Note

This requires that the buffer be complete valid JSON that requires no more than 1024 tokens. For larger objects, or to parse what may be an incomplete string, call json_parse[_len] and check the return value.