[SOLVED] curl in c, output in jq

Issue

I make a curl call in c like so:

#include <curl/curl.h>

#include <stdio.h>

int main(){

    CURL *ch;

    CURLcode res;

    ch = curl_easy_init();

    curl_easy_setopt(ch, CURLOPT_URL, "https://jsonplaceholder.typicode.com/todos/2");

    res = curl_easy_perform(ch);

    curl_easy_cleanup(ch);

    }

it prints to the command line just fine:

$./mycurl
{
  "userId": 1,
  "id": 2,
  "title": "quis ut nam facilis et officia qui",
  "completed": false
} 

but I would like to use jq to parse the json and output from one compiled c file. how do i do this without doing: ./mycurl | jq

but rather compile it all in one?

Solution

As noted it's a much better idea to use a JSON library to parse the output. A library provides you with an API which is a more direct way to express what you are trying to do, and will provide you with better error handling. That said, I was curious, so here is how you could pass the data to jq:

#define _POSIX_C_SOURCE 2
#include <curl/curl.h>
#include <stdio.h>
#include <sys/wait.h>
#include <unistd.h>

int main(void) {
    FILE *f = popen("jq .userId", "w");
    if(!f) {
        printf("jq failed\n");
        return 1;
    }
    dup2(fileno(f), STDOUT_FILENO);
    CURL *ch = curl_easy_init();
    curl_easy_setopt(ch, CURLOPT_URL, "https://jsonplaceholder.typicode.com/todos/2");
    CURLcode res = curl_easy_perform(ch);
    curl_easy_cleanup(ch);
    fclose(stdout);
    return pclose(f);
}

and output:

1

Answered By - Allan Wind

Answer Checked By - Dawn Plyler (WPSolving Volunteer)