[ale] Perl Question

[Danny Cox]

	I was bitten by this yesterday (sorry, I was busy doing other things
last night, or I would have posted then).

	I attempted to use the "grep EXPR, @list" described in "Programming
Perl" and it didn't work as I expected.

	Background: I wanted to set up a list and stuff 3 digit numbers into it
(actually EDI document names: 810, 850, 208, etc.).  I wanted to use
grep (the Perl grep) to let me know if that number was already extant. 
So, I used the following fragment:

	$count = grep $doc, @list

where $doc == "810" for example.  When the list was empty, $count was
0.  When I successfully stuffed something in it, it was always 1,
regardless of what $doc was and what @list contained.  Not what I
expected.

	I then noticed the little bit I missed: EXPR can be a pattern, but it
doesn't have to be.  I changed the frag to:

	$count = grep /$doc/, @list

and it worked fine!  Glorious!

	Now: what the BLEEP was the first form doing, and why would anyone want
to use it?  Having used Unix/Linux since '81, this behaviour totally
befuddled me for awhile.  I mean, grep (the command) always searches for
patterns, right?  This, for me, clearly violates the "path of least
surprise".

	Oh, well, we live and learn.

	Perl wizards: please enlighten me!

	Thanks!

-- 
kernel, n.: A part of an operating system that preserves the
medieval traditions of sorcery and black art.

Danny

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