robinvanemden/postman-echo.c

## postman-echo.c
/**
 * Simple program to POST a HTTP request
 *
 * see:
 *  https://docs.postman-echo.com/?version=latest
 *  https://aticleworld.com/http-get-and-post-methods-example-in-c/
 *  https://stackoverflow.com/questions/11208299/how-to-make-an-http-get-request-in-c-without-libcurl
 *  https://stackoverflow.com/questions/22077802/simple-c-example-of-doing-an-http-post-and-consuming-the-response
 */

#include <stdio.h>      /* printf, sprintf */
#include <stdlib.h>     /* exit */
#include <unistd.h>     /* read, write, close */
#include <string.h>     /* memcpy, memset */
#include <sys/socket.h> /* socket, connect */
#include <netinet/in.h> /* struct sockaddr_in, struct sockaddr */
#include <netdb.h>      /* struct hostent, gethostbyname */

static void error(const char *msg)
{
    perror(msg);
    exit(1);
}

int main(int argc, char *argv[])
{
    static int port = 80;
    static const char *host = "postman-echo.com";
    static const char *message_fmt = "POST /post?data=%s HTTP/1.0\r\n"
                                        "Content-Type: text/plain\r\n"
                                        "Content-Length: %zu\r\n"
                                        "\r\n%s";

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

    if (argc < 3) {
        puts("Usage:\n\t<data> <body>\n");
        exit(0);
    }

    sprintf(message, message_fmt, argv[1], strlen(argv[2]), argv[2]);
    printf("Request:\n%s\n", message);

    /* Create the socket */
    fd = socket(AF_INET, SOCK_STREAM, 0);
    if (fd < 0) error("ERROR opening socket");

    /* Lookup the ip address */
    server = gethostbyname(host);
    if (server == NULL) error("ERROR, no such host");

    /* Fill in the structure */
    memset(&serv_addr, 0, sizeof(serv_addr));
    serv_addr.sin_family = AF_INET;
    serv_addr.sin_port = htons(port);
    memcpy(&serv_addr.sin_addr.s_addr, server->h_addr, server->h_length);

    /* Connect the socket */
    if (connect(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
        error("ERROR connecting");

    /* Send the request */
    total = strlen(message);
    sent = 0;
    do {
        bytes = write(fd, message + sent, total - sent);
        if (bytes < 0)
            error("ERROR writing message to socket");
        if (bytes == 0) break;
        sent += bytes;
    } while (sent < total);

    /* Receive the response */
    memset(response, 0, sizeof(response));
    total = sizeof(response) - 1;
    received = 0;
    do {
        bytes = read(fd, 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");

    (void) close(fd);

    /* process response */
    printf("Response:\n%s\n", response);

    return 0;
}
	/**
	* Simple program to POST a HTTP request
	*
	* see:
	* https://docs.postman-echo.com/?version=latest
	* https://aticleworld.com/http-get-and-post-methods-example-in-c/
	* https://stackoverflow.com/questions/11208299/how-to-make-an-http-get-request-in-c-without-libcurl
	* https://stackoverflow.com/questions/22077802/simple-c-example-of-doing-an-http-post-and-consuming-the-response
	*/

	#include <stdio.h> /* printf, sprintf */
	#include <stdlib.h> /* exit */
	#include <unistd.h> /* read, write, close */
	#include <string.h> /* memcpy, memset */
	#include <sys/socket.h> /* socket, connect */
	#include <netinet/in.h> /* struct sockaddr_in, struct sockaddr */
	#include <netdb.h> /* struct hostent, gethostbyname */

	static void error(const char *msg)
	{
	perror(msg);
	exit(1);
	}

	int main(int argc, char *argv[])
	{
	static int port = 80;
	static const char *host = "postman-echo.com";
	static const char *message_fmt = "POST /post?data=%s HTTP/1.0\r\n"
	"Content-Type: text/plain\r\n"
	"Content-Length: %zu\r\n"
	"\r\n%s";

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

	if (argc < 3) {
	puts("Usage:\n\t<data> <body>\n");
	exit(0);
	}

	sprintf(message, message_fmt, argv[1], strlen(argv[2]), argv[2]);
	printf("Request:\n%s\n", message);

	/* Create the socket */
	fd = socket(AF_INET, SOCK_STREAM, 0);
	if (fd < 0) error("ERROR opening socket");

	/* Lookup the ip address */
	server = gethostbyname(host);
	if (server == NULL) error("ERROR, no such host");

	/* Fill in the structure */
	memset(&serv_addr, 0, sizeof(serv_addr));
	serv_addr.sin_family = AF_INET;
	serv_addr.sin_port = htons(port);
	memcpy(&serv_addr.sin_addr.s_addr, server->h_addr, server->h_length);

	/* Connect the socket */
	if (connect(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
	error("ERROR connecting");

	/* Send the request */
	total = strlen(message);
	sent = 0;
	do {
	bytes = write(fd, message + sent, total - sent);
	if (bytes < 0)
	error("ERROR writing message to socket");
	if (bytes == 0) break;
	sent += bytes;
	} while (sent < total);

	/* Receive the response */
	memset(response, 0, sizeof(response));
	total = sizeof(response) - 1;
	received = 0;
	do {
	bytes = read(fd, 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");

	(void) close(fd);

	/* process response */
	printf("Response:\n%s\n", response);

	return 0;
	}