Question 1

How do I parse a JSON file with json-c?

Accepted Answer

Read the file into a string, then use json_tokener_parse_ex() from json_tokener.h to convert it to a json_object. Always check for errors and free the tokener with json_tokener_free() after parsing.

Question 2

What's better: json-c or cJSON?

Accepted Answer

json-c offers reference counting for easier memory management and features like JSON Pointer, while cJSON is a single-file library with manual memory control. Choose json-c for automatic memory handling or cJSON for minimal dependencies.

Question 3

Is json-c thread-safe for concurrent access?

Accepted Answer

No, it only supports partial threading with optional atomic operations for json_object_get() and json_object_put(), and enabling it can significantly impact performance. Full multi-threaded access to object trees is not supported.

Question 4

Can I use json-c in an embedded Linux project?

Accepted Answer

Yes, it's lightweight and can be cross-compiled, but consider the memory overhead from reference counting and ensure your toolchain supports CMake and dependencies like gcc.

Question 5

How to avoid memory leaks when using json-c?

Accepted Answer

Leverage the reference counting by always calling json_object_put() on the root object to free the tree, and use json_object_get() to retain references when objects need to outlive their parents.

Question 6

Does json-c support streaming JSON parsing?

Accepted Answer

No, json-c parses entire JSON strings into memory objects, which may not be efficient for very large files. Consider alternative libraries if streaming or incremental parsing is required.

json-c

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