Jansson varargs wrapper

example.c

#include <stdlib.h>
#include <jansson.h>

size_t json_printf(json_t *obj, const char *format, ...) {
    va_list ap;
    size_t count = 0;
    char *name;

    va_start(ap, format);
    for (count = 0; *format != '\0'; ++format) {
        name = va_arg(ap, char *);
        switch (*format) {
            case 'i':
                json_object_set_new(obj, name, json_integer(va_arg(ap, int)));
                count++;
                break;

            case 's':
                json_object_set_new(obj, name, json_string(va_arg(ap, char *)));
                count++;
                break;

            case 'd':
                json_object_set_new(obj, name, json_real(va_arg(ap, double)));
                count++;
                break;

            default:
                printf("WTF, skipping %s\n", format);
                break;
        }
    }
    va_end(ap);
    return count;
}

int main(int argc, char **argv) {
    int i;
    json_t *obj = json_object();
    size_t count; 

    count = json_printf(obj, "isd", "Age", 3, "name", "Brian", "Worth", 3.3);

    char *str = json_dumps(obj, 0);  
    printf("SIZE: %d\nEncoded: %s\n", count, str);
    json_decref(obj); 

    // convert str back into a json_t object
    json_error_t err = {0}; 
    obj = json_loads(str, 0, &err);
    free(str); 
}

gistfile1.txt

$ gcc -l jansson test.c 
$ ./a.out 
SIZE: 3
Encoded: {"Age": 3, "name": "Brian", "Worth": 3.2999999999999998}
$