c
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

void error(const char *msg) { perror(msg); exit(0); }

int main(int argc,char *argv[]) {
    int portno =        80;
    char *host =        "api.url.com";
    char *message_fmt = "POST /apikey=%s&command=%s HTTP/1.0\r\n\r\n";

    struct hostent *server;
    struct sockaddr_in serv_addr;
    int sockfd, bytes, sent, received, total;
    char message[1024],response[4096];

    if (argc < 3) { puts("Parameters: <apikey> <command>"); exit(0); }
    sprintf(message,message_fmt,argv[1],argv[2]);
    printf("Request:\n%s\n",message);
    sockfd = socket(AF_INET, SOCK_STREAM, 0);
    if (sockfd < 0) error("ERROR opening socket");
    server = gethostbyname(host);
    if (server == NULL) error("ERROR, no such host");
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(portno);
    memcpy(&serv_addr.sin_addr.s_addr,server->h_addr,server->h_length);
    if (connect(sockfd,(struct sockaddr *)&serv_addr,sizeof(serv_addr)) < 0)
        error("ERROR connecting");
    total = strlen(message);
    sent = 0;
    do {
        bytes = write(sockfd,message+sent,total-sent);
        if (bytes < 0)
            error("ERROR writing message to socket");
        if (bytes == 0)
            break;
        sent+=bytes;
    } while (sent < total);
    memset(response,0,sizeof(response));
    total = sizeof(response)-1;
    received = 0;
    do {
        bytes = read(sockfd,response+received,total-received);
        if (bytes < 0)
            error("ERROR reading response from socket");
        if (bytes == 0)
            break;
        received+=bytes;
    } while (received < total);
    if (received == total)
        error("ERROR storing complete response from socket");
    close(sockfd);
    printf("Response:\n%s\n",response);

    return 0;
}