bind Invalid argument - c

Question

I'm playing with the unix sockets. The code compiles fine but I get the following message on execute
Invalid argument
Here is the code i use. It's pretty simple I think
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#define PORT 7000
int main(){
int socket_desc;
struct sockaddr_in address;
socket_desc = socket(AF_INET, SOCK_STREAM, 0);
if(socket_desc == -1)
perror("Create socket");
/* type of socket created in socket() */
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY;
/* set port */
address.sin_port = htons(PORT);
while(1) {
/* bind the socket to the port specified above */
if(bind(socket_desc,(struct sockaddr *)&address, sizeof(address)) < 0) {
perror("Error");
exit(-1);
}
}
return 0;
}

Answer 1

The problem is that you're trying to bind more than once -- what's with the while(1) loop?
while(1) {
/* bind the socket to the port specified above */
if(bind(socket_desc,(struct sockaddr *)&address, sizeof(address)) < 0) {
perror("Error");
exit(-1);
}
}
bind() succeeds the first time, and on the subsequent call it fails with EINVAL, which means (from man 2 bind):
[EINVAL] socket is already bound to an address and the protocol does not support binding to a new address. Alternatively, socket may have been
shut down.
As a side note, it's probably a good idea to zero out the sockaddr prior to passing it in:
#include <string.h>
/* ... */
memset(&address, 0, sizeof(address));
address.sin_family = AF_INET;
address.sin_addr.s_addr = INADDR_ANY;
address.sin_port = htons(PORT);