#include?“apue.h“
#include?

static?void
lockabyte（const?char?*name?int?fd?off_t?offset）
{
	if?（writew_lock（fd?offset?SEEK_SET?1）?		err_sys（“%s:?writew_lock?error“?name）;
	printf（“%s:?got?the?lock?byte?%lld\n“?name?（long?long）offset）;
}

int
main（void）
{
	int		fd;
	pid_t	pid;

	/*
	?*?Create?a?file?and?write?two?bytes?to?it.
	?*/
	if?（（fd?=?creat（“templock“?FILE_MODE））?		err_sys（“creat?error“）;
	if?（write（fd?“ab“?2）?!=?2）
		err_sys（“write?error“）;

	TELL_WAIT（）;
	if?（（pid?=?fork（））?		err_sys（“fork?error“）;
	}?else?if?（pid?==?0）?{			/*?child?*/
		lockabyte（“child“?fd?0）;
		TELL_PARENT（getppid（））;
		WAIT_PARENT（）;
		lockabyte（“child“?fd?1）;
	}?else?{						/*?parent?*/
		lockabyte（“parent“?fd?1）;
		TELL_CHILD（pid）;
		WAIT_CHILD（）;
		lockabyte（“parent“?fd?0）;
	}
	exit（0）;
}

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2014-03-20?09:38??apue.3e\
?????目錄???????????0??2014-03-20?09:38??apue.3e\advio\
?????文件?????????827??2014-03-20?09:38??apue.3e\advio\deadlock.c
?????文件?????????172??2012-07-05?08:08??apue.3e\advio\fixup.awk
?????文件?????????197??2014-03-20?09:38??apue.3e\advio\lockfile.c
?????文件?????????641??2014-03-20?09:07??apue.3e\advio\Makefile
?????文件????????1536??2014-03-20?09:38??apue.3e\advio\mandatory.c
?????文件????????1228??2014-03-20?09:38??apue.3e\advio\mcopy2.c
?????文件?????????590??2014-03-20?09:38??apue.3e\advio\nonblockw.c
?????文件?????????492??2014-03-20?09:38??apue.3e\advio\readn.c
?????文件?????????866??2014-03-20?09:38??apue.3e\advio\rot13a.c
?????文件????????3199??2014-03-20?09:38??apue.3e\advio\rot13c2.c.in
?????文件?????????498??2014-03-20?09:38??apue.3e\advio\writen.c
?????目錄???????????0??2014-03-20?09:38??apue.3e\daemons\
?????文件????????1580??2014-03-20?09:38??apue.3e\daemons\init.c
?????文件?????????159??2012-07-23?02:21??apue.3e\daemons\Makefile
?????文件????????1526??2014-03-20?09:38??apue.3e\daemons\reread.c
?????文件????????1232??2014-03-20?09:38??apue.3e\daemons\reread2.c
?????文件?????????761??2014-03-20?09:38??apue.3e\daemons\single.c
?????目錄???????????0??2014-03-20?09:38??apue.3e\datafiles\
?????文件?????????340??2014-03-20?09:38??apue.3e\datafiles\getpwnam.c
?????文件?????????273??2014-03-20?09:07??apue.3e\datafiles\Makefile
?????文件?????????471??2014-03-20?09:38??apue.3e\datafiles\strftime.c
?????目錄???????????0??2014-03-20?09:38??apue.3e\db\
?????文件?????????797??2014-03-20?09:38??apue.3e\db\apue_db.h
?????文件???????24592??2014-03-20?09:38??apue.3e\db\db.c
?????文件????????1043??2012-07-23?02:22??apue.3e\db\Makefile
?????文件?????????513??2014-03-20?09:38??apue.3e\db\t4.c
?????文件?????????656??2013-04-27?10:18??apue.3e\DISCLAIMER
?????目錄???????????0??2014-03-20?09:38??apue.3e\environ\
?????文件?????????680??2014-03-20?09:38??apue.3e\environ\cmd1.c
............此處省略482個文件信息