Re: Help with argument to a subroutine

while (<STDIN>) { will always return true, since even if the line entered is empty, you will still get a \n from STDIN. So you need a different form of loop. Also, parse_header() needs the entire header passed to it - passing each line one at a time will just make many calls to parse_header(), only the last of which will have the full header.

What you need is something more like the following (assuming your data is coming in through STDIN - I haven't tested that part):

use strict;
use warnings;

my $header;
while (1) {
    chomp($_ = <STDIN>);
    last if !$_;
    $header .= "$_\n";
}
parse_header($header);

sub parse_header {
    my $header = $_[0];
    print $header;
    ## Do necessary $header processing
}
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Re^2: Help with argument to a subroutine by unixhome (Novice) on May 15, 2006 at 19:22 UTC
Ted: Sorry about that. I did not put it on my first posting but the first while loop already knows when to execute the sub (when $_ =~ /^$?/). You see, if I run both of those loops independantly from each other (piping the output of one to the second) as in: # cat header.eml \| ./first_loop.pl \| ./second_loop.pl It works. This is an excersise in Perl programming (with a real purpose...) and I cannot even say (Perl modules) out loud...	[reply]
Re^2: Help with argument to a subroutine by GrandFather (Saint) on May 15, 2006 at 19:11 UTC
Or `while (<STDIN>) { chomp; last if !$_; # or other suitable termination test $header .= "$_\n"; }` [download] DWIM is Perl's answer to Gödel	[reply] [d/l]