TCP/IP Server

// TCP/IP SERVER
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define MAX_CLIENT_NUMBER 8

int main(int argc, char *argv[])
{
    int sockfd, newsockfd, port, clilen;
    char buffer[256];
    struct sockaddr_in serv_addr, cli_addr;
    int n;

    if(argc < 2){
        puts("[-] Error: No port provided");
        return -1;
    }

    sockfd = socket(AF_INET, SOCK_STREAM, 0); // socket()
    if(sockfd < 0){
        puts("[-] Error: Opening socket");
        return -1;
    }

    memset((char*) &serv_addr, 0, sizeof(serv_addr));
    port = atoi(argv[1]);

    serv_addr.sin_family = AF_INET;
    serv_addr.sin_addr.s_addr = INADDR_ANY;
    serv_addr.sin_port = htons(port);

    if(bind(sockfd, (struct sockaddr*) &serv_addr, sizeof(serv_addr)) < 0){ // bind()
        printf("[-] Error: Binding");
    }

    listen(sockfd, MAX_CLIENT_NUMBER); // listen()

    newsockfd = accept(sockfd, (struct sockaddr*) &cli_addr, &clilen); // accept()
    if(newsockfd < 0){
        puts("[-] Error: Accept");
        return -1;
    }

    memset(buffer, 0, 256);

    n = read(newsockfd, buffer, 255); // read()
    if(n < 0){
        puts("[-] Error: Reading");
        return -1;
    }

    printf("Message: %s\n", buffer);

    n = write(newsockfd, "Message received!", 17); // write()
    if(n < 0){
        puts("[-] Error: Write");
        return -1;
    }

    if(shutdown(sockfd, 2) < 0){ // close()
        puts("[-] Error: Close");
        return -1;
    }

    return 0;
}