Simple template for tcp client socket in C for Linux. Based on https://www.youtube.com/watch?v=bdIiTxtMaKA

tcpclientsocket.c

#include <sys/socket.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <netdb.h>

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>

#define PORT 80

#define BUFF_SIZE 4096

#define SOCK_ADDR struct sockaddr

int main(int argc, char **argv){
    int sockfd, n,errcode; 
    int sendbytes;
    struct sockaddr_in servaddr;
    char sendline[BUFF_SIZE];
    char readline[BUFF_SIZE];

    // usage check 
    if(argc != 2) 
        return 0; 

    sockfd = socket(AF_INET,SOCK_STREAM,0);

    bzero(&servaddr,sizeof(servaddr));
    servaddr.sin_family = AF_INET;
    servaddr.sin_port = htons(PORT);

    if(1 > (errcode = inet_pton(AF_INET,argv[1],&servaddr.sin_addr))){
        printf("[%d] %s does not look like correct ip addr ",errcode,argv[1]);
        return 0; // 1 - success, 0 - fail
    }

    if(0 > (errcode = connect(sockfd,&servaddr,sizeof(servaddr)))){
        printf("[%d] Cannoc connect",errcode);
        return 0; // 0 - success, -1 - fail
    }

    sprintf(sendline,"GET / HTTP/1.1.\r\n\r\n");
    sendbytes = strlen(sendline);

    if(0 >= (errcode = write(sockfd, sendline,sendbytes))){
        printf("[%d] Cannot write to file descriptor",errcode);
        return 0; // write returns number of zeros 
    }

    memset(readline,0,BUFF_SIZE);

    while((n = read(sockfd,readline,BUFF_SIZE))> 0 ){
        printf("%s",readline);
    };
    if(n < 0) return 0;

    return 0;
}