Path: utzoo!attcan!uunet!fed!m1rcd00
From: m1rcd00@fed.FRB.GOV (Bob Drzyzgula)
Newsgroups: comp.lang.perl
Subject: Data-selected output channels
Message-ID: <547@arccs1.fed.FRB.GOV>
Date: 2 Mar 90 14:58:21 GMT
Sender: news@fed.FRB.GOV
Reply-To: rcd@fed.frb.gov
Followup-To: comp.lang.perl
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Organization: Federal Reserve Board, Wash, DC
Lines: 53


I would like to be able to direct my perl program output to one
of several *simultaneously open* files, depending on input data.
I had thought that perl's filehandle indirection capability would
do this for me, but I guess not. The result of the script

#!/usr/bin/perl

foreach $i ("file1", "file2", "file3")
	{
		$openstring = ">$i";
		open openstring;
		print openstring "$openstring\n";
	}

foreach $i ("file1", "file2", "file3")
	{
		$openstring = "$i";
		print openstring "$openstring\n";
	}

is three files with the contents:

"file1":

>file1

"file2":

>file2

"file3":

>file3
file1
file2
file3

So apparantly an indirect filehandle is associated with *the most
recently opened file* that went by that name.  Setting $openstring = ">$i"
in the second loop changes only file3 by putting a ">" at the beginning
of the second through fourth lines, and using a different variable name
in place of "openstring" in the second loop results in nothing being
written as a result of the second loop, as does changing the last
print statement to "print $openstring ...".  Hence there appears to
be no variable look-up done on the filehandle during the print statment,
only during the open statement.

Is there any way to do what I want, short of doing an open every time
I want to write a record? Given my application, that's about 570,000
opens. The Solbourne is pretty fast, but... :-)

-- 
Bob Drzyzgula
rcd@fed.frb.gov, uunet!fed!rcd
Federal Reserve Board, Washington, DC  20551