json string extraction

json.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

typedef struct www {
  char * srv_name;
  char * srv_alias;
  char * doc_root;
} www;
char * jsonVal(const char * json, const char * pattern);

int main(int argc, char *argv[]) {
  www data;

  char buff[2048] = "[{datatype:www,package:{srv_name:angrybits.pl,srv_alias:www.angrybits.pl,doc_root:/var/www/angrybits.pl/htdocs}}]";

  char * datatype = jsonVal(buff, "datatype:");

  if(!strcmp(datatype, "www")) {
    data.srv_name = jsonVal(buff, "srv_name:");
    data.srv_alias = jsonVal(buff, "srv_alias:");
    data.doc_root =  jsonVal(buff, "doc_root:");
    printf("<VirtualHost *:80>\n");
    printf("  ServerName %s\n", data.srv_name);
    printf("  ServerAlias %s\n", data.srv_alias);
    printf("  DocumentRoot %s\n", data.doc_root);
  }

  free(datatype);

  return 0;
}
char * jsonVal(const char * json, const char * pattern) {
  char * val = NULL;

  size_t pattern_len = strlen(pattern);
  const char * val_pos = strstr(json, pattern) + pattern_len;

  int i = 0;
  size_t len = 0;
  char tmp[512];
  memset(tmp, '\0', 512);

  while(*val_pos != ',' && *val_pos != '}') {
    tmp[i] = *val_pos;
    val_pos++;
    i++;
  }
  len = strlen(tmp) + 1;
  val = (char *) malloc(len * sizeof(char));
  strcpy(val, tmp);

  return val;
}