unix domain socket 进程间通信简析

Linux系统有多种进程间通信方式，如信号、消息队列、管道等，socket是其中一种，socket使用unix domain 模式进行进程间通信

//服务端代码

#include <stdio.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <sys/un.h>

#include <unistd.h>

#define UNIX_SERV "/tmp/unix_serv" //文件路径名

int main(void)

{

int sock_fd;

struct sockaddr_un serv;

struct sockaddr_un cli;

int ret;

socklen_t serv_len;

sock_fd = socket(AF_UNIX, SOCK_DGRAM, 0); //采用数据报协议

if(sock_fd < 0)

{

perror("fail to socket");

}

unlink(UNIX_SERV); //若文件 存在，则删除

memset(&serv, 0, sizeof(serv));

serv.sun_family = AF_UNIX; //Unix

strncpy(serv.sun_path, UNIX_SERV, sizeof(serv.sun_path)-1); //拷贝文件名

serv_len = sizeof(serv);

ret = bind(sock_fd, (struct sockaddr *)&serv, serv_len); //服务器需要绑定

if(ret == -1)

{

perror("fail to bind");

}

int recv_size;

char buf[1024];

socklen_t cli_len;

memset(&cli, 0, sizeof(cli));

cli_len = sizeof(cli);

while(1)

{

recv_size = recvfrom(sock_fd, buf, sizeof(buf), 0,

(struct sockaddr *)&cli, &cli_len);

if(recv_size > 0)

{

if(strncmp(buf, "exit", strlen("exit") ) == 0)

{

printf("client exit\n");

break;

}

buf[recv_size-1] = '\0';

printf("recv buf:%s from client\n", buf);

}

}

close(sock_fd);

unlink(UNIX_SERV);

return 0;

}

//客户端代码

#include <stdio.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <sys/un.h>

#include <unistd.h>

#define UNIX_SERV "/tmp/unix_serv" //服务端文件名

//注：客户端代码可以不绑定地址，如不绑定，则不需要客户端文件名;绑定客户端会生成客户端文件

#define UNIX_CLI "/tmp/unix_cli" //客户端文件名

int main(void)

{

int sock_fd;

struct sockaddr_un serv;

struct sockaddr_un cli;

int ret;

socklen_t serv_len;

socklen_t cli_len;

sock_fd = socket(AF_UNIX, SOCK_DGRAM, 0);

if(sock_fd < 0)

{

perror("fail to socket");

}

unlink(UNIX_CLI);

memset(&cli, 0, sizeof(cli));

memset(&serv, 0, sizeof(serv));

cli_len = sizeof(cli);

cli.sun_family = AF_UNIX;

strncpy(cli.sun_path, UNIX_CLI, sizeof(cli.sun_path)-1);

serv_len = sizeof(serv);

serv.sun_family = AF_UNIX;

strncpy(serv.sun_path, UNIX_SERV, sizeof(serv.sun_path)-1);

ret = bind(sock_fd, (struct sockaddr *)&cli, cli_len);

if(ret == -1)

{

perror("fail to bind");

}

int read_size;

int send_size;

char buf[1024];

while(1)

{

read_size = read(STDIN_FILENO, buf, sizeof(buf));

if(read_size > 0)

{

send_size = sendto(sock_fd, buf, read_size, 0,

(struct sockaddr *)&serv, serv_len);

if(serv_len > 0)

{

if(strncmp(buf, "exit", 4) == 0)

{

printf("client exit\n");

break;

}

buf[read_size-1] = '\0';

printf("send buf: %s\n", buf);

}

}

}

close(sock_fd);

unlink(UNIX_CLI);

return 0;

}