Hi,
I am reading and understanding code from a book.
I am copy pasting the exact code which I have.
Following program is for client.c
#include<sys/types.h>
#include<sys/socket.h>
#include <stdio.h>
#include <sys/un.h>
#include <unistd.h>>
#include <stdlib.h>
int main() {
int sockfd;
int len;
struct sockaddr_un address;
int result;
char ch = 'A';
sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
address.sun_family = AF_UNIX;
strcpy(address.sun_path, "server_socket");I was not able to understand the use of server_socket in above strcpy function.
Where does this come to picture
len = sizeof(address);
result = connect(sockfd, (struct sockaddr *)&address, len);
if(result == -1) {
perror("oops: client1");
exit(1);
}
write(sockfd, &ch, 1);
read(sockfd, &ch, 1);
printf("char from server = %c\n", ch);
close(sockfd);
exit(0);
}When I run the code as
gcc client.c -o client.othen on terminal I see each time letter B why is that happening.
and following program is for server.c
#include<sys/types.h>
#include<sys/socket.h>
#include<stdio.h>
#include <sys/un.h>
#include <unistd.h>
#include<stdlib.h>
int main()
{
int server_sockfd, client_sockfd;
int server_len, client_len;
struct sockaddr_un server_address;
struct sockaddr_un client_address;
unlink("server_socket");
server_sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
server_address.sun_family = AF_UNIX;
strcpy(server_address.sun_path, "server_socket");I am not clear with use of server_address.sun_path
I understand that server_address is a struct of type sockaddr_un
but what is sun_path I had seen the file linux/un.h
but could not understand.
server_len = sizeof(server_address);
bind(server_sockfd, (struct sockaddr *)&server_address, server_len);
listen(server_sockfd, 5);
while (1) {
char ch;
printf("server waiting\n");
client_len = sizeof(client_address);
client_sockfd = accept(server_sockfd,
(struct sockaddr *)&client_address,
&client_len);
read(client_sockfd, &ch, 1);
ch++;
write(client_sockfd, &ch, 1);
close(client_sockfd);
}
}