Undefined reference error while using json-c

Question

I want to use json-c in my program. While compiling (linking) I'm getting errors:

parsejson.c:(.text.startup+0xf): undefined reference to `json_object_new_object'
parsejson.c:(.text.startup+0x1c): undefined reference to `json_object_new_string'
parsejson.c:(.text.startup+0x2b): undefined reference to `json_object_new_int'
parsejson.c:(.text.startup+0x3a): undefined reference to `json_object_new_boolean'
parsejson.c:(.text.startup+0x4a): undefined reference to `json_object_new_double'
parsejson.c:(.text.startup+0x52): undefined reference to `json_object_new_array'
parsejson.c:(.text.startup+0x5f): undefined reference to `json_object_new_string'
parsejson.c:(.text.startup+0x6e): undefined reference to `json_object_new_string'
parsejson.c:(.text.startup+0x7b): undefined reference to `json_object_new_string'
parsejson.c:(.text.startup+0x8b): undefined reference to `json_object_array_add'
parsejson.c:(.text.startup+0x96): undefined reference to `json_object_array_add'
parsejson.c:(.text.startup+0xa1): undefined reference to `json_object_array_add'
parsejson.c:(.text.startup+0xb3): undefined reference to `json_object_object_add'
parsejson.c:(.text.startup+0xc3): undefined reference to `json_object_object_add'
parsejson.c:(.text.startup+0xd3): undefined reference to `json_object_object_add'
parsejson.c:(.text.startup+0xe5): undefined reference to `json_object_object_add'
parsejson.c:(.text.startup+0xf5): undefined reference to `json_object_object_add'
parsejson.c:(.text.startup+0xfd): undefined reference to `json_object_to_json_string'

I've json-c and my program on the same folder and included it using #include <json-c/json.h>.

Answer 1

When linking statically, gcc brings the symbols that are already encountered. So if you are passing -ljson before your source files, gcc will take the static library and then eventually does not really need anything out of it. So you should put the libraries to link against after your code.

Though you have not shared what your compilation command line say, I would recommend trying something like:

$ gcc -g -v -Wall -std=gnu99 -static -L/path/to/compiled/library parsejson.c -o parsejson -ljson