Path: utzoo!attcan!uunet!elroy.jpl.nasa.gov!swrinde!zaphod.mps.ohio-state.edu!wuarchive!wuphys!marty
From: marty@wuphys.wustl.edu (Marty Olevitch)
Newsgroups: comp.lang.perl
Subject: Weirdness with <> input operator
Message-ID: <1991Feb28.171434.6125@wuphys.wustl.edu>
Date: 28 Feb 91 17:14:34 GMT
Reply-To: marty@wuphys.UUCP (Marty Olevitch)
Organization: Physics Dept, Washington U. in St Louis
Lines: 32

Well, now that "Programming Perl" is available, I have learned
enough to get quite confused! I've been converting a few
of my little C utilities into perl, and ran into this problem.

Say I have an array of (open) file handles @handle. Then if I try

	for($i = 0; $i <= $#handle; $i++) {
		$line = <$handle[$i]>;
	}

it doesn't put the next line from the file into $line, but
rather the name of the file handle (and seems to miss every other
one). However, the following:

	for($i = 0; $i <= $#handle; $i++) {
		$filehandle = $handle[$i];
		$line = <$filehandle>;
	}

does read the next line into $line. Is this the way it is supposed to
work? This is using perl 3.0 at patchlevel 44.

Also, I found that using the <> operator with an array argument,
for example <@foo> , reads the next item in the foo array. But I didn't
see this documented in the perl book, at least where the main discussion
of the input operator takes place. Going back to the first example,
does perl think that $handle[$i] is supposed to be an array?

Marty Olevitch				Internet: marty@wuphys.wustl.edu
Washington University			UUCP:     uunet!wugate!wuphys!marty
Physics Department, Campus Box 1105	Bitnet:   marty@wuphys.WUSTL
St Louis MO 63130 USA			Tel:      (314) 889-6285