HTTP Request in C using low level write to socket functionality

socket.c

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

#include <netinet/tcp.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netdb.h>

int socket_connect(char *host, in_port_t port){
	struct hostent *hp;
	struct sockaddr_in addr;
	int on = 1, sock;     

	if((hp = gethostbyname(host)) == NULL){
		herror("gethostbyname");
		exit(1);
	}
	bcopy(hp->h_addr, &addr.sin_addr, hp->h_length);
	addr.sin_port = htons(port);
	addr.sin_family = AF_INET;
	sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP);
	setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (const char *)&on, sizeof(int));

	if(sock == -1){
		perror("setsockopt");
		exit(1);
	}
	
	if(connect(sock, (struct sockaddr *)&addr, sizeof(struct sockaddr_in)) == -1){
		perror("connect");
		exit(1);

	}
	return sock;
}
 
#define BUFFER_SIZE 1024

int main(int argc, char *argv[]){
	int fd;
	char buffer[BUFFER_SIZE];

	if(argc < 3){
		fprintf(stderr, "Usage: %s <hostname> <port>\n", argv[0]);
		exit(1); 
	}
       
	fd = socket_connect(argv[1], atoi(argv[2])); 
	write(fd, "GET /\r\n", strlen("GET /\r\n")); // write(fd, char[]*, len);  
	bzero(buffer, BUFFER_SIZE);
	
	while(read(fd, buffer, BUFFER_SIZE - 1) != 0){
		fprintf(stderr, "%s", buffer);
		bzero(buffer, BUFFER_SIZE);
	}

	shutdown(fd, SHUT_RDWR); 
	close(fd); 

	return 0;
}

@Andermutu it has been a while , but in case you're still interested :)

This is not valid HTTP:

"GET / HTTP/1.1\r\nHost: [https://api.telegram.org/botmybottokenhere/sendMessage?chat_id=mychatidhere&text=mymessagehere\r\nConnection](https://api.telegram.org/botmybottokenhere/sendMessage?chat_id=mychatidhere&text=mymessagehere%5Cr%5CnConnection): close\r\n\r\n"

The host header should contain only the host. You've given it a full URL!

And your request path is just / so it would never work.

Also, you're trying to send a https request which means the socket needs to be encrypted. And notice that the protocol doesn't go in the HTTP request itself as that refers to the transport being used.

So, your request should look like this (\r\n replaced with simple new-lines for readability, you still need them in a real request):

GET /botmybottokenhere/sendMessage?chat_id=mychatidhere&text=mymessagehere HTTP/1.1
Host: api.telegram.org
Connection: close

@dimuthnc

localhost:8080/services

write(fd, "GET /services HTTP/1.1\r\n\r\n", strlen("GET /services HTTP/1.1\r\n\r\n"));

Run command:

gcc socket.c -o socket
./socket localhost 8080

You may want to use bcopy instead of copy at line 22