进程创建

#include <unistd.h>
#include <stdio.h>
#include<sys/wait.h>

int main( void )
{
    int filedes[2];
    char buf[80];
    pid_t pid;

    pipe( filedes );
    pid=fork();
    if (pid > 0)
    {
        printf( "This is in the father process.\n" );
        char s[] = "this is write by pipe.\n";
        write( filedes[1], s, sizeof(s) );
        close( filedes[0] );
        close( filedes[1] );
    }
    else if(pid == 0)
    {
        printf( "This is in the child process.\n" );
        read( filedes[0], buf, sizeof(buf) );
        printf( "%s\n", buf );
        close( filedes[0] );
        close( filedes[1] );
    }

    waitpid( pid, NULL, 0 );
    return 0;
}