Linux下的Socket通信是一種基于文件的IPC通信,也可以是基于其他設(shè)備的IPC通信。它可以在本機(jī)內(nèi)不同進(jìn)程間實(shí)現(xiàn)通信,也可以在實(shí)現(xiàn)不同主機(jī)之間的通信。
socket的創(chuàng)建步驟
服務(wù)端
1.通過(guò)socket()函數(shù)創(chuàng)建socket
2.通過(guò)bind函數(shù)綁定socket于設(shè)備地址
3.通過(guò)listen監(jiān)聽(tīng)指定的socket
4.通過(guò)accept等待客戶端的連接
客戶端
1.通過(guò)socket()函數(shù)創(chuàng)建socket
2.通過(guò)connect連接到服務(wù)端
待經(jīng)過(guò)上面的步驟后,服務(wù)端和客戶端已經(jīng)建立了鏈接,可以通過(guò)write/read或者sendto/recvfrom發(fā)送/接收數(shù)據(jù).
示列
1.服務(wù)端
//s_unix.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#define UNIX_DOMAIN "/tmp/UNIX.domain"
int main(void)
{
socklen_t clt_addr_len;
int listen_fd;
int com_fd;
int ret;
int i;
static char recv_buf[1024];
int len;
struct sockaddr_un clt_addr;
struct sockaddr_un srv_addr;
listen_fd=socket(PF_UNIX,SOCK_STREAM,0);
if(listen_fd<0)
{
perror("cannot create communication socket");
return 1;
}
//set server addr_param
srv_addr.sun_family=AF_UNIX;
strncpy(srv_addr.sun_path,UNIX_DOMAIN,sizeof(srv_addr.sun_path)-1);
unlink(UNIX_DOMAIN);
//bind sockfd & addr
ret=bind(listen_fd,(struct sockaddr*)&srv_addr,sizeof(srv_addr));
if(ret==-1)
{
perror("cannot bind server socket");
close(listen_fd);
unlink(UNIX_DOMAIN);
return 1;
}
//listen sockfd
ret=listen(listen_fd,1);
if(ret==-1)
{
perror("cannot listen the client connect request");
close(listen_fd);
unlink(UNIX_DOMAIN);
return 1;
}
//have connect request use accept
len=sizeof(clt_addr);
com_fd=accept(listen_fd,(struct sockaddr*)&clt_addr,&len);
if(com_fd<0)
{
perror("cannot accept client connect request");
close(listen_fd);
unlink(UNIX_DOMAIN);
return 1;
}
//read and printf sent client info
printf("/n=====info=====/n");
for(i=0;i<4;i++)
{
memset(recv_buf,0,1024);
int num=read(com_fd,recv_buf,sizeof(recv_buf));
printf("Message from client (%d)) :%s/n",num,recv_buf);
}
close(com_fd);
close(listen_fd);
unlink(UNIX_DOMAIN);
return 0;
}
2.客戶端
//c_unix.c
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#define UNIX_DOMAIN "/tmp/UNIX.domain"
int main(void)
{
int connect_fd;
int ret;
char snd_buf[1024];
int i;
static struct sockaddr_un srv_addr;
//creat unix socket
connect_fd=socket(PF_UNIX,SOCK_STREAM,0);
if(connect_fd<0)
{
perror("cannot create communication socket");
return 1;
}
srv_addr.sun_family=AF_UNIX;
strcpy(srv_addr.sun_path,UNIX_DOMAIN);
//connect server
ret=connect(connect_fd,(struct sockaddr*)&srv_addr,sizeof(srv_addr));
if(ret==-1)
{
perror("cannot connect to the server");
close(connect_fd);
return 1;
}
memset(snd_buf,0,1024);
strcpy(snd_buf,"message from client");
//send info server
for(i=0;i<4;i++)
write(connect_fd,snd_buf,sizeof(snd_buf));
close(connect_fd);
return 0;
}