#include
#include
main ()
{
pid_t pid;
printf("fork!");
pid=vfork();
if (pid < 0)
printf("error in fork!");
else if (pid == 0)
printf("i am the child process, my process id is %d\n",getpid());
else
printf("i am the parent process, my process id is %d\n",getpid());
}
输出：
fork!i am the child process, my process id is 17757
i am the parent process, my process id is 17756
fork!i am the child process, my process id is 17758
怎么会输出三个语句呢
奶茶dsk 于 2012-08-10 17:37:23发表:
NAME
vfork - create a child process and block parent
SYNOPSIS
#include
#include
pid_t vfork(void);
STANDARD DESCRIPTION
(From XPG4 / SUSv2 / POSIX draft.) The vfork() function has the same
effect as fork(), except that the behaviour is undefined if the process
created by vfork() either modifies any data other than a variable of
type pid_t used to store the return value from vfork(), or returns from
the function in which vfork() was called, or calls any other function
before successfully calling _exit() or one of the exec family of func-
tions.
vfork生成的进程和父进程共享页表，对进程的行为有特殊的要求，lz的代码是未定义的
linux08071151 于 2012-08-10 11:40:13发表:
5# z767900438
首先感谢热友的解答 ！刚接触linux,希望大家不吝赐教。加了exit(0)之后，当父进程执行完了之后，程序可以正常的退出，即输出前两条语句。我想知道为什么不加就会输出三条呢。
z767900438 于 2012-08-09 22:22:10发表:
建议楼主在末尾加个exit（0），再试试看可不可以
linux08071151 于 2012-08-08 18:49:48发表:
3# freelevei
为什么最后又输出子进程的那部分了呢
freelevei 于 2012-08-08 13:42:07发表:
vfork创建的子进程与父进程共享的，子进程先返回。
NetFlow 于 2012-08-08 08:44:22发表:
这1圆不好挣啊