requestor_hw_mssiraj.c

/*
COMPILATION COMMAND:
/home/mssiraj/buildroot-2022.02.3/output/host/usr/bin/arm-linux-gcc --sysroot=/home/mssiraj/buildroot-2022.02.3/output/staging requestor_hw_mssiraj.c -o requestor_hw_mssiraj -lcurl -uClibc -lc -largp

COMPILATION NOTES:
1. Please replace "/home/mssiraj/buildroot-2022.02.3/" with the path to your own buildroot directory.

2. This program uses the "argp" library which requires the following configuration in buildroot:
make nconfig -> Target packages -> Libraries -> Other -> argp-standalone
*/

/*
USAGE EXAMPLES:
requestor_hw_mssiraj --get --url=http://eu.httpbin.org/anything
requestor_hw_mssiraj --post --url=http://eu.httpbin.org/anything "name=sadman&uni=UNM"
requestor_hw_mssiraj --put --url=http://eu.httpbin.org/anything "project=libcurl HTTP"
requestor_hw_mssiraj --delete --url=http://eu.httpbin.org/anything "name=sadman&uni=UNM"
requestor_hw_mssiraj -?/--help or --usage
*/

#include <stdio.h>
#include <curl/curl.h>
#include <stdlib.h>
#include <argp.h>

#define OK 0
#define INIT_ERR 1
#define REQ_ERR 2

#define URL "http://localhost"

/* Program documentation. */
static char doc[] = "requestor_hw -- a program that uses libcurl to communicate via HTTP.";

/* A description of the arguments we accept. */
static char args_doc[] = "STRING (Please put this string value within single or double quotes). If not set, default string value will be used.";

/* Program options. */
static struct argp_option options[] = {
  {"get", 'g', 0, 0, "HTTP GET Request" },
  {"post", 'o', 0, 0, "HTTP POST Request" },
  {"put", 'p', 0, 0, "HTTP PUT Request" },
  {"delete", 'd', 0, 0, "HTTP DELETE Request" },
  {"url", 'u', "URL", 0, "Set URL. Otherwise, default URL: http://localhost will be set." },
  { 0 }
};

/* Used by main to communicate with parse_opt. */
struct arguments
{
  char *args;
  int http_get;
  int http_post;
  int http_put;
  int http_delete;
  int user_url;
  char *url;
  // char *text;
};

/* Parse a single option. */
static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  /* Get the input argument from argp_parse, which we
     know is a pointer to our arguments structure. */
  struct arguments *arguments = state->input;

  switch (key)
    {
    case 'g':
      printf("\nPerforming HTTP GET Request...\n");
      arguments->http_get = 1;
      break;
    case 'o':
      printf("\nPerforming HTTP POST Request...\n");
      arguments->http_post = 1;
      break;
    case 'p':
      printf("\nPerforming HTTP PUT Request...\n");
      arguments->http_put = 1;
      break;
    case 'd':
      printf("\nPerforming HTTP DELETE Request...\n");
      arguments->http_delete = 1;
      break;
    case 'u':
      arguments->user_url = 1;
      arguments->url = arg;
      // printf(arguments.url);
      break;

    case ARGP_KEY_ARG:
      //if (state->arg_num >= 1)
        /* Too many arguments. */
        //argp_usage (state);
      arguments->args = arg;
      break;

    //case ARGP_KEY_END:
      //if (state->arg_num < 1)
        /* Not enough arguments. */
        //argp_usage (state);
      //break;

    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}

/* Our argp parser. */
static struct argp argp = { options, parse_opt, args_doc, doc };

int main(int argc, char **argv) {

    struct arguments arguments;

    /* Default values. */
    arguments.http_get = 0;
    arguments.http_post = 0;
    arguments.http_put = 0;
    arguments.http_delete = 0;
    arguments.user_url = 0;
    arguments.url = "http://localhost";
    arguments.args = "INPUT=Default STRING Value";

    /* Parse our arguments; every option seen by parse_opt will
        be reflected in arguments. */
    argp_parse(&argp, argc, argv, 0, 0, &arguments);

    if (arguments.user_url) {
        printf("\nGiven URL = %s\n", arguments.url);
    } else {
        printf("\nGiven URL = %s (default URL)\n", arguments.url);
    }
    printf("\nGiven STRING = %s\n", arguments.args);

    // No HTTP Request
        if (arguments.http_get == 0 &&
            arguments.http_post == 0 &&
            arguments.http_put == 0 &&
            arguments.http_delete == 0) {
            printf("\nNo HTTP Request received from User.\nUse the option -?/--help or --usage for more information.\n");
            }


    CURL *curl;
    CURLcode res;
    curl = curl_easy_init();

    if (curl) {
        curl_easy_setopt(curl, CURLOPT_URL, arguments.url);
        // HTTP GET
        if (arguments.http_get) {
            curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);
            printf("\nHTTP GET Response:\n");
            res = curl_easy_perform(curl);
            }
        // HTTP POST
        if (arguments.http_post) {
            curl_easy_setopt(curl, CURLOPT_POST, 1L);
            curl_easy_setopt(curl, CURLOPT_POSTFIELDS, arguments.args);
            printf("\nHTTP POST Response:\n");
            res = curl_easy_perform(curl);
            }
        // HTTP PUT
        if (arguments.http_put) {
            curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "PUT");
            curl_easy_setopt(curl, CURLOPT_POSTFIELDS, arguments.args);
            printf("\nHTTP PUT Response:\n");
            res = curl_easy_perform(curl);
            }
        // HTTP DELETE
        if (arguments.http_delete) {
            curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "DELETE");
            curl_easy_setopt(curl, CURLOPT_POSTFIELDS, arguments.args);
            printf("\nHTTP DELETE Response:\n");
            res = curl_easy_perform(curl);
            }
        if (res != CURLE_OK) {
            return REQ_ERR;
            }
        curl_easy_cleanup(curl);
        } else {
            return INIT_ERR;
            }

    return OK;
}