p11-2.c

SUN Solaris8平台下进程间通信

#include <sys/types.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include "err_exit.h"
/* 从管道读字符然后输出到stdout */
void read_from_pipe (int fd0)
{
    FILE *stream;
    int c;
    stream = fdopen (fd0, "r");          /* 建立描述字与标准I/O流的连接 */
    printf("read from pipe:");
    while ((c = fgetc (stream)) != EOF)
        putchar (c);
    fclose (stream);
}
/* 写出一些字符至管道*/
void write_to_pipe (int fd1)
{
    FILE *stream;
    stream = fdopen (fd1, "w");        /* 建立描述字与标准I/O流的连接 */
    fprintf (stream, "hello, world!\n");
    fclose (stream);
}
int main (void)
{
    pid_t pid;
    int mypipe[2];
    /* 创建管道 */
    if (pipe (mypipe)) 
        err_exit("Pipe failed.\n");
    pid = fork ();  /* 派生子进程 */
    if (pid < (pid_t) 0) 
        err_exit ("Fork failed.\n");   /* fork 失败 */
    else if (pid == (pid_t) 0) {       /* 这是子进程 */
        close(mypipe[1]);
        read_from_pipe (mypipe[0]);
    }
    else {    /* 这是父进程 */
        close(mypipe[0]);
        write_to_pipe (mypipe[1]);
    }
    exit(EXIT_SUCCESS);
}