cjson

Lightweight json parser for C projects

int cjson_parse(const char *str, const char *fmt, int ops, ...);

Usage

main.c

/*
int cjson_parse(const char *str, const char *fmt, int ops, char *buff, int n);
int cjson_parse(const char *str, const char *fmt, int ops, const char **begin, const char **end);
int cjson_parse(const char *str, const char *fmt, int ops, char **alloc);
*/

int main(int ac, char *av[])
{
 char strbuf[10000];
 int  stat;
 int  fd;
 int  ret;

 (void)ac;
 fd = open(av[1], O_RDONLY);
 ret = read(fd, strbuf, 10000);
 strbuf[ret] = 0;

For given buffer size

 char buff[10000];
 stat = cjson_parse(strbuf, av[2], O_BUFF, buff, 10000);
 printf("%s\n", buff);

For begin and end pointers

 const char *begin;
 const char *end; 
 stat = cjson_parse(strbuf, av[2], O_PTR, &begin, &end);
 while (begin < end)
  printf("%c", *(begin++));
 printf("\n");

For a new string from the heap

 char *str;
 stat = cjson_parse(strbuf, av[2], O_ALLOC, &str);
 if (0 <= stat)
 {
  printf("%s\n", str);
  free(str);
 }

 return (stat);
}

tmp.json

{
 "id": 14433,
 "name": "api-red",
 "description": "",
 "image": null,
 "website": "",
 "public": true,
 "scopes": [
  "public",
  "projects",
  "profile",
  "elearning",
  "tig",
  "forum"
 ],
}

Run

./a.out tmp.json .scopes[0]

Output

"public"

tmp2.json

[
 {
  "id": 1,
  "api-name": "t1",
 },
 {
  "id": 2,
  "api-name": "t1",
 },
 {
  "id": 2,
  "api-name": "t1",
 }
]

Run

./a.out tmp2.json [1].id

Output

2