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From: todd@pinhead.pegasus.com (Todd Ogasawara)
Newsgroups: comp.lang.perl,comp.unix.sysv386
Subject: Perl unpack/tacct file
Keywords: pack, unpack, tacct files
Message-ID: <1991May04.185409.24228@pinhead.pegasus.com>
Date: 4 May 91 18:54:09 GMT
Organization: Hawaii Medical Service Association
Lines: 51


I just started using Perl a few weeks ago and have run into a problem when
trying to use unpack to look at 'tacct' type accounting files on an 386 box
running Interactive UNIX 2.2 (UNIX System V/386 R3). I'm pretty sure I
understand the structure of this file type since C programs I've written to
read it work fine. The C structure of this file looks like this:

#p = prime time, np = non-prime time
#struct	tacct {
#	unsigned short	ta_uid;		/* userid */
#	char		ta_name[8];	/* login name */
#	float		ta_cpu[2];	/* cum cpu time, p/np (mins) */
#	float		ta_kcore[2];	/* cum kcore-minutes, p/np */
#	float		ta_con[2];	/* cum connect time p/np, mins */
#	float		ta_du;		/* cum disk usage */
#	long		ta_pc;		/* count of processes */
#	unsigned short	ta_sc;		/* count of login sessions */
#	unsigned short	ta_dc;		/* count of disk samples */
#	unsigned short	ta_fee;		/* fee for special services */
#};

Here's the perl program I've tried to use to read a tacct file with. (BTW,
I'm using Perl 4.0 patch level 3).

open(TACCT,"/usr/adm/acct/sum/tacct");

while(read(TACCT,$tacct,52)) {
	($uid,$name,$cpuP,$cpuNP,$kcoreP,$kcoreNP,$conP,$conNP,
	 $du,$pc,$sc,$dc,$fee) = 
		unpack("S A8 f f f f f f f l S S S",$tacct);
	local($TCONNECT) = $conP + $conNP;
	printf "%4d %8s %7.2f %d %d\n",
		$uid, $name, $TCONNECT, $sc, $dc;
}

The $uid and $name variables contain what I expect it to. However,
everything else that follows seems to be one off. I.e., The $dc variable
should contain the number of disk samples but seems to contain the number
of login sessions instead. The floating point values are all over the
place. I know that I must be reading in the floating point variables
incorrectly, but I don't know what it is that I'm doing wrong. BTW, I have
the Wall & Schwartz "Programming Perl" book and have gone through the
sections describing pack and unpack several times to try to understand what
is going on here.

Thanks for any help/hints anyone can offer.

-- 
Todd Ogasawara ::: Hawaii Medical Service Association
Internet       ::: todd@pinhead.pegasus.com
Telephone      ::: (808) 536-9162 ext. 7