c - socket programming , bind() error -

my code have written server implementation not working. program cant bind() socket address , generate error.

code

#include<stdio.h> #include<unistd.h> #include<sys/types.h> #include<sys/socket.h> #include<netinet/in.h> #include<string.h> #include<stdlib.h> #include <netdb.h>  int main(int argc , char* argv[]) {     int socket_descriptor;     struct sockaddr_in server;     char buffer[512];     int rval;     int socket_a;      if(socket_descriptor = socket(af_inet, sock_stream , 0) < 0)     {         perror("error @ creating socket");         exit(1);     }      server.sin_family  = af_inet;     server.sin_addr.s_addr = inaddr_any;     server.sin_port = htons(5000);      if(bind(socket_descriptor,(struct sockaddr * )&server,sizeof(server)) < 0)     {         perror("error @ binding");         exit(1);     }  } 

error

error @ binding: socket operation on non-socket .

here's problem:

if(socket_descriptor = socket(af_inet, sock_stream , 0) < 0) 

the less-than operator < has higher precedence assignment operator =. above equivalent to:

if(socket_descriptor = (socket(af_inet, sock_stream , 0) < 0)) 

assuming socket succeeds, file descriptor returned not negative, comparison evaluate 0 (i.e. false) , value assigned socket_descriptor. , since file descriptor 0 stdin, error socket operation on non-socket.

adding proper set of parenthesis assign socket socket_descriptor:

if ((socket_descriptor = socket(af_inet, sock_stream , 0)) < 0)