使用管道实现进程间的双向通信

#include<stdio.h>

#include<unistd.h>

int main(int argc, char * argv[])

{

int f_des1[2];

int f_des2[2];

int pid;

char msg[BUFSIZ];

char p_msg[BUFSIZ];

if(argc != 2)

{

printf("Usage: %s message\n",argv[0]);

return 1;

}

if(pipe(f_des1) == -1)

{

printf("cannot create the IPC pipe");

return 1;

}

pid = fork();

if(pid == -1)

{

printf("cannot create new process");

return 1;

}

else if(pid == 0)

{

close(f_des1[1]);

close(f_des2[0]);

if(read(f_des1[0], msg, BUFSIZ) == -1)

{

printf("child process cannot read data from pipe");

return 1;

}

else

{

printf("in child proccess, receive message: %s\n",msg);

}

if(write(f_des2[1], msg, strlen(msg)) == -1)

{

printf("child process cannot write data to pipe");

return 1;

}

else

{

printf("in child process , send message back: %s\n", argv[1]);

}

exit(0);

}

else

{

close(f_des1[0]);

close(f_des2[1]);

if(write(f_des1[1], argv[1], strlen(argv[1])) == -1)

{

printf("parent process cannot write data to pipe");

return 1;

}

else

{

printf("in parent process , send mwssage: %s\n",argv[1]);

}

if(read(f_des2[0], p_msg, BUFSIZ) == -1)

{

printf("parent process cannot read data from pipe");

return 1;

}

else

{

printf("in parent proccess, receive message: %s\n",p_msg);

}

wait(NULL);

exit(0);

}

return 0;

}