tellwait2.c

UNIX编程高级环境（第二版）的进程部分的程序源码

#include    <sys/types.h>
#include    "ourhdr.h"

static void charatatime(char *);

int
main(void)
{
    pid_t    pid;

    TELL_WAIT();

    if ( (pid = fork()) < 0)
        err_sys("fork error");
    else if (pid == 0) {
        WAIT_PARENT();        /* parent goes first */
        charatatime("output from child\n");
    } else {
        charatatime("output from parent\n");
        TELL_CHILD(pid);
    }
    exit(0);
}

static void
charatatime(char *str)
{
    char    *ptr;
    int        c;

    setbuf(stdout, NULL);            /* set unbuffered */
    for (ptr = str; c = *ptr++; )
        putc(c, stdout);
}