libhttp

Light-weight C library for HTTP/1.1 requests. Meant for embedded environments or whereever libcurl would be just too much.

Fitness

If there's any chance you will ever need to make HTTPS requests or do anything else than just plain simple HTTP/1.1 requests, use libcurl.

This library aims to remain as simple and portable as possible to offer a nice and small alternative.

Sample

Simple GET request

For a simple GET request you just need to call http_request() and http_response():

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

#include "http.h"

int main(int argc, char **argv) {
	int sd;
	struct http_message msg;

	if (!--argc || (sd = http_request(*++argv)) < 1) {
		perror("http_request");
		return -1;
	}

	memset(&msg, 0, sizeof(msg));

	while (http_response(sd, &msg) > 0) {
		if (msg.content) {
			write(1, msg.content, msg.length);
		}
	}

	close(sd);

	if (msg.header.code != 200) {
		fprintf(
			stderr,
			"error: returned HTTP code %d\n",
			msg.header.code);
	}

	return 0;
}

Custom request

If you want to add/tweak some header values or do a POST request, use the low level functions http_parse_url(), http_connect() and http_send() to compose your request like this:

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

#include "http.h"

int post(int sd, struct http_url *url) {
	char buf[1024];

	snprintf(
		buf,
		sizeof(buf),
		"\
POST /%s HTTP/1.1\r\n\
User-Agent: Mozilla/4.0 (Linux)\r\n\
Host: %s\r\n\
Accept: */*\r\n\
Content-Length: 13\r\n\
Connection: close\r\n\
\r\n\
q=Test&btn=Go\r\n\
\r\n",
		url->query,
		url->host);

	if (http_send(sd, buf)) {
		perror("http_send");
		return -1;
	}

	return 0;
}

int main(int argc, char **argv) {
	struct http_url *url;
	struct http_message msg;
	int sd;

	if (!(url = http_parse_url(*++argv)) ||
			!(sd = http_connect(url))) {
		free(url);
		perror("http_connect");
		return -1;
	}

	memset(&msg, 0, sizeof(msg));

	if (!post(sd, url)) {
		while (http_response(sd, &msg) > 0) {
			if (msg.content) {
				write(1, msg.content, msg.length);
			}
		}
	}

	free(url);
	close(sd);

	if (msg.header.code != 200) {
		fprintf(
			stderr,
			"error: returned HTTP code %d\n",
			msg.header.code);
	}

	return 0;
}

Testing

There's a bash script to test any URL list against libhttp:

$ cd test && bash test.sh [FILE-WITH-URLS]

If you find bugs, please report them.