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From: cpcahil@virtech.uucp (Conor P. Cahill)
Newsgroups: comp.unix.wizards
Subject: Re: When does access date get set on tty device
Keywords: access date tty device
Message-ID: <1990Aug28.131209.17038@virtech.uucp>
Date: 28 Aug 90 13:12:09 GMT
References: <1067@prcrs.UUCP>
Reply-To: cpcahil@virtech.UUCP (Conor P. Cahill)
Organization: Virtual Technologies Inc., Sterling VA
Lines: 29

In article <1067@prcrs.UUCP> mcvic@prcrs.UUCP (David McVicar) writes:
>Question:
>
>At what point does the st_atime field in the inode get updated when writing
>to a tty device?

The st_atime will be updated by a call to any of the following system calls:

	creat, mknod, pipe, utime, and read.

st_mtime will be updated by a call to any of the following system calls:

	creat, mknod, pipe, utime, and write.

(Actually the *time is updated following completion of the operation, just
 prior to the system call returning)

>Problem: We have 300 baud devices that take too long to print reports and 
> 	 our auto-logout daemon detects an old access time and
>	 no cpu usage for that tty and terminates the user's processes.

You probably want to use the latter of st_atime and st_mtime for your idle
time calculations.


-- 
Conor P. Cahill            (703)430-9247        Virtual Technologies, Inc.,
uunet!virtech!cpcahil                           46030 Manekin Plaza, Suite 160
                                                Sterling, VA 22170