A JSON writer library for C. It's built with a similar interface to the JSMN Reader, but it's not actually built from the jsmn library.

It does however, have a similar design to JSMN Reader; usuable in a wide range of compilers because it was written within ANSI-C. With the same sort of design for installation.

And yes, I know, it's not really the most elegant title for the library, but eh? It writes JSON data, so straight to the point?

• Portable.
• Written in ANSI-C, so is (likely) compatible with ancient compilers.
• Writes JSON (obviously), with a series of write commands. Such as jswrwriter_gen_string().
  • Automatically sanitizes input strings making use of / or ".
• Settings for writing JSON in a strict format.
• Settings for beautify or minify styled JSON output.
• Error handling, for writing errors.
• Debug printing functions for outputing the contents of the write commands.
• Built-in writing functions to file or string output.

The installation is more or less the same as jsmnreader & jsmn, but you only need to include jswrwriter.h to your source file.

The macros JSWR_STATIC (for making symbols static) and JSWR_H (for avoiding duplicate symbols) are present, because it is a library of a single header file.

You can initalize JSMN Writer with jswrwriter_init(), and do need to free it with jswrwriter_free() when it's done, due to allocating data on initalization.

#include "jswrwriter.h"

...

jswrwriter_obj myjswr;
jswrwriter_init(&myjswr);

...

jswrwriter_free(&myjswr);

(That's right, the documentation is in the README.md file.)

• jswrwriter_init(&jswr): Initalizes the writer data, as well as sets up malloc(). Should be the first function used.
• jswrwriter_free(&jswr): Frees the writer data from memory. Should be the last function used.
• jswrwriter_parse(&jswr): Populates the JSON command data into the writer's string data. Can output results.
• jswrwriter_filewrite(filename, &jswr): Saves the writer's string data to a file. Can output results.

• jswrwriter_set_style(style, &jswr): Set's the output style of the JSON. Minify if false, Beautify if true. The JSON is written in Beautify by default.
• jswrwriter_set_leniency(allowextradata, allowrootdata, &jswr): Set's the error leniency for parsing the JSON for writing.

By standard use, you shouldn't likely need to make use of either functions.

• jswrwriter_gen_string(input_str, input_str_size, &jswr): Generates a string. Key strings are generated through this function.
• jswrwriter_gen_int(input_int, &jswr): Generates an int.
• jswrwriter_gen_uint(input_int, &jswr): Generates an unsigned int.
• jswrwriter_gen_float(input_float, &jswr): Generates a float.
• jswrwriter_gen_bool(input_int, &jswr): Generates a boolean output (true/false).
• jswrwriter_gen_true(&jswr): Generates a true value.
• jswrwriter_gen_false(&jswr): Generates a false value.
• jswrwriter_gen_null(&jswr): Generates a null value.
• jswrwriter_gen_object_open(&jswr): Generates an object opening. {
• jswrwriter_gen_object_close(&jswr): Generates an object closing. }
• jswrwriter_gen_array_open(&jswr): Generates an array opening. [
• jswrwriter_gen_array_close(&jswr): Generates an array closing. ]
• jswrwriter_gen_raw(input_str, input_str_size, &jswr): Generates a "raw" string.
• jswrwriter_gen_beautify_break(&jswr): Prevents a line break for the next token.

• jswrwriter_debugprint(&jswr): Outputs a list of the commands used for the JSON writing.

• JSWR_SUCCESS: JSON written successfully. Not an error, but listed for consistency.
• JSWR_ERROR_EXPECTEDBRACKET: Expected closing bracket.
• JSWR_ERROR_MISMATCH: Bracket type mistmatch.
• JSWR_ERROR_UNEXPECTEDBRACKET: Unexpected closing bracket.
• JSWR_ERROR_NOKEY: Key expected.
• JSWR_ERROR_UNCLOSEDKEY: Unclosed key detected.
• JSWR_ERROR_INVALBRACKET: Invalid brackets.
• JSWR_ERROR_TOKENOUTSIDE: Detected writing outside of object or array. Can be disabled by jswrwriter_set_leniency().
• JSWR_ERROR_UNEXPECTEDEXTRA: Unexpected extra data. Can be disabled by jswrwriter_set_leniency().
• JSWR_ERROR_WRITEFAIL: File writing failure.

Constants for loading errors, to be used with jsmnreader_parse() or jsmnreader_filewrite().

This software is distributed under MIT license, so feel free to integrate it in your commercial products.