CODEWITHSUNDEEP
csockets
Robin Rydholm
Robin Rydholm

Reputation: 17

passing arguments to the bind() function

i have this programm which should only bind a socket to a port and i always get

failure while binding.

I can compile it without a problem.

should i add something to the servAddr?

#include <stdio.h>
#include <stdlib.h> 
#include <string.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "Practical.h"

int main(int argc , char* argv[]){

    if(argc!=2){
        printf("Parameters : <server Port>");
    }

    in_port_t servPort=atoi(argv[1]);

    int servSock;
    if(servSock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP)<0){
        printf("error socket");
    }

    struct sockaddr_in servAddr;
    memset(&servAddr,0,sizeof(servAddr));
    servAddr.sin_family=AF_INET;
    servAddr.sin_addr.s_addr=htonl(INADDR_ANY);
    servAddr.sin_port=htons(servPort);

    if(bind(servSock,(struct sockaddr*) &servAddr,sizeof(servAddr)) < 0){
        printf("failure while binding");
    }
}

Upvotes: 2

Views: 108

Answers (1)

Sergio
Sergio

Reputation: 8209

= has priority lower than <, add extra braces:

if((servSock=socket(AF_INET,SOCK_STREAM,IPPROTO_TCP))<0){
  printf("error socket");}

Without these braces servSock is 1 or 0, that is definitely not what you want. Also note that without priviledges you can not bind to ports lower that 1024.

Upvotes: 6

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