same file descriptors of all client connections. How to differentiate clients ?
I want to send diff client diff reply from other child process of server
For that I use fd of client.
Every forked child process of server replies to particular client (child created on that client connection) even if fd is same.
But different processes(other children of server i.e. exec) couldn't identify that client with same fd in used in forked child.
How can I differentiate client on other processes ??
Code:
/* server process */
#include <ctype.h>
#include <sys/types.h>
#include <sys/socket.h>
#include<stdlib.h>
#include<stdio.h>
#include <netinet/in.h>
#include <signal.h>
#define SIZE sizeof(struct sockaddr_in)
void catcher(int sig);
int newsockfd;
int main(void)
{
int sockfd;
char c;
struct sockaddr_in server = {AF_INET, 7000, INADDR_ANY};
static struct sigaction act;
act.sa_handler = catcher;
sigfillset(&(act.sa_mask));
sigaction(SIGPIPE, &act, NULL);
/* set up the transport end point */
if ( (sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
perror("socket call failed");
exit(1);
}
/* bind an address to the end point */
if ( bind(sockfd, (struct sockaddr *)&server, SIZE) == -1)
{
perror("bind call failed");
exit(1);
}
/* start listening for incoming connections */
if ( listen(sockfd, 5) == -1 )
{
perror("listen call failed");
exit(1) ;
}
for (;;)
{
/* accept a connection */
if ( (newsockfd = accept(sockfd, NULL, NULL)) == -1)
{
perror("accept call failed");
continue;
}
printf("New connection. File descriptor fd is %d\n",newsockfd);
/* spawn a child to deal with the connection */
if ( fork() == 0)
{
while (recv(newsockfd, &c, 1, 0) > 0)
{
c = toupper(c);
send(newsockfd, &c,1, 0);
}
/* when client is no longer sending information the socket can be closed and the child process terminated */
close(newsockfd);
exit (0);
}
/* parent doesn't need the newsockfd */
close(newsockfd);
}
}
void catcher(int sig)
{
close(newsockfd);
exit (0);
}
Code:
/* client process */
#include <ctype.h>
#include <sys/types.h>
#include<stdlib.h>
#include<stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#define SIZE sizeof(struct sockaddr_in)
int main(void)
{
int sockfd;
char c, rc;
struct sockaddr_in server = {AF_INET, 7000};
/* convert and store the server's IP address */
server.sin_addr.s_addr = inet_addr("127.0.0.1");
/* set up the transport end point */
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
{
perror("socket call failed");
exit(1);
}
/* connect the socket to the server's address */
if ( connect (sockfd, (struct sockaddr *)&server, SIZE) == -1)
{
perror("connect call failed");
exit(1);
}
/* send and receive information with the server */
for(rc = '\n';;)
{
if (rc == '\n')
printf("Input a lower case character\n");
c = getchar();
send(sockfd, &c, 1, 0);
if (recv(sockfd, &rc, 1, 0) >0)
printf("%c", rc);
else
{
printf("server has died\n");
close(sockfd);
exit(1);
}
}
}
