fork1.c

APUE(第二版)的随书源代码,与第一版的代码相比增加了一些章节的代码(详见第二版的说明)

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

int		glob = 6;		/* external variable in initialized data */
char	buf[] = "a write to stdout\n";

int
main(void)
{
	int		var;		/* automatic variable on the stack */
	pid_t	pid;

	var = 88;
	if (write(STDOUT_FILENO, buf, sizeof(buf)-1) != sizeof(buf)-1)
		err_sys("write error");
	printf("before fork\n");	/* we don't flush stdout */

	if ( (pid = fork()) < 0)
		err_sys("fork error");
	else if (pid == 0) {		/* child */
		glob++;					/* modify variables */
		var++;
	} else
		sleep(2);				/* parent */

	printf("pid = %d, glob = %d, var = %d\n", getpid(), glob, var);
	exit(0);
}