mirror of
https://github.com/lxsang/silk.git
synced 2024-11-14 17:28:22 +01:00
77 lines
2.2 KiB
C
Executable File
77 lines
2.2 KiB
C
Executable File
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "../jsmn.h"
|
|
|
|
/*
|
|
* A small example of jsmn parsing when JSON structure is known and number of
|
|
* tokens is predictable.
|
|
*/
|
|
|
|
static const char *JSON_STRING =
|
|
"{\"user\": \"johndoe\", \"admin\": false, \"uid\": 1000,\n "
|
|
"\"groups\": [\"users\", \"wheel\", \"audio\", \"video\"]}";
|
|
|
|
static int jsoneq(const char *json, jsmntok_t *tok, const char *s) {
|
|
if (tok->type == JSMN_STRING && (int) strlen(s) == tok->end - tok->start &&
|
|
strncmp(json + tok->start, s, tok->end - tok->start) == 0) {
|
|
return 0;
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
int main() {
|
|
int i;
|
|
int r;
|
|
jsmn_parser p;
|
|
jsmntok_t t[128]; /* We expect no more than 128 tokens */
|
|
|
|
jsmn_init(&p);
|
|
r = jsmn_parse(&p, JSON_STRING, strlen(JSON_STRING), t, sizeof(t)/sizeof(t[0]));
|
|
if (r < 0) {
|
|
printf("Failed to parse JSON: %d\n", r);
|
|
return 1;
|
|
}
|
|
|
|
/* Assume the top-level element is an object */
|
|
if (r < 1 || t[0].type != JSMN_OBJECT) {
|
|
printf("Object expected\n");
|
|
return 1;
|
|
}
|
|
|
|
/* Loop over all keys of the root object */
|
|
for (i = 1; i < r; i++) {
|
|
if (jsoneq(JSON_STRING, &t[i], "user") == 0) {
|
|
/* We may use strndup() to fetch string value */
|
|
printf("- User: %.*s\n", t[i+1].end-t[i+1].start,
|
|
JSON_STRING + t[i+1].start);
|
|
i++;
|
|
} else if (jsoneq(JSON_STRING, &t[i], "admin") == 0) {
|
|
/* We may additionally check if the value is either "true" or "false" */
|
|
printf("- Admin: %.*s\n", t[i+1].end-t[i+1].start,
|
|
JSON_STRING + t[i+1].start);
|
|
i++;
|
|
} else if (jsoneq(JSON_STRING, &t[i], "uid") == 0) {
|
|
/* We may want to do strtol() here to get numeric value */
|
|
printf("- UID: %.*s\n", t[i+1].end-t[i+1].start,
|
|
JSON_STRING + t[i+1].start);
|
|
i++;
|
|
} else if (jsoneq(JSON_STRING, &t[i], "groups") == 0) {
|
|
int j;
|
|
printf("- Groups:\n");
|
|
if (t[i+1].type != JSMN_ARRAY) {
|
|
continue; /* We expect groups to be an array of strings */
|
|
}
|
|
for (j = 0; j < t[i+1].size; j++) {
|
|
jsmntok_t *g = &t[i+j+2];
|
|
printf(" * %.*s\n", g->end - g->start, JSON_STRING + g->start);
|
|
}
|
|
i += t[i+1].size + 1;
|
|
} else {
|
|
printf("Unexpected key: %.*s\n", t[i].end-t[i].start,
|
|
JSON_STRING + t[i].start);
|
|
}
|
|
}
|
|
return EXIT_SUCCESS;
|
|
}
|