File Handle wierdness

the_slycer has asked for the wisdom of the Perl Monks concerning the following question:

OK, what is going on here. I've been playing with Net::SMTP::Server, which is kind of fun, problem is, the outfile in the below code gets nothing, nada, blank (it's created but blank). The print to STDOUT works fine though...

#!/usr/bin/perl
use strict;
use Net::SMTP::Server;
use Net::SMTP::Server::Client;

open (OUT => ">outfile")|| die "Could not open $!";
print OUT "HELLO";
my $server=new Net::SMTP::Server("localhost","25");
while (my $conn=$server->accept()){
        my $client=new Net::SMTP::Server::Client($conn) ||
                die "Unable to handle client connection: $!";
        $client->process;
        my $msg=$client->{MSG};
        print OUT "$msg\n";
        print $msg;
}
[download]

sob

Comment on File Handle wierdness Download Code

Replies are listed 'Best First'.
Re: File Handle wierdness by the_slycer (Chaplain) on Nov 22, 2000 at 11:40 UTC
I should also mention, even the "print OUT "HELLO"" does not appear in the file	[reply]
(tye)Re: File Handle wierdness by tye (Sage) on Nov 22, 2000 at 11:48 UTC
The "HELLO" won't be flushed to the file until you write more or close the file handle. You might want to do: `{ my $old= select(OUT); $\|= 1; select($old); }` [download] or `use IO::Handle; ... OUT->autoflush(1);` [download] so that you program hanging on accept() doesn't fool you, for example. - tye (but my friends call me "Tye")	[reply] [d/l] [select]
Re: File Handle wierdness by geektron (Curate) on Nov 22, 2000 at 11:40 UTC
you're not opening a filehandle correctly. `open( OUT, ">outfile" );` [download] if you're planning to blow away the contents of the file each time you run your script, or `open( OUT, ">>outfile" );` [download] if you want to update your code. i'm surprised you're getting a filehandle opened at all . . . UPDATE: i stand corrected. tye has the right idea - the filehandle is blocking. i had to do similar 'magic' on a project. close the filehandle, then re-open it. that'll flush the buffer, and you should see ( at least ) the 'hello' string.	[reply] [d/l] [select]
Re: Re: File Handle wierdness by snax (Hermit) on Nov 22, 2000 at 14:25 UTC
the_slycer is correct. From perlman:perldata: It is often more readable to use the => operator between key/value pairs. The => operator is mostly just a more visually distinctive synonym for a comma, but it also arranges for its left-hand operand to be interpreted as a string--if it's a bareword that would be a legal identifier. This makes it nice for initializing hashes: Since OUT is a legal bareword he's OK.	[reply]
Re: Re: File Handle wierdness by the_slycer (Chaplain) on Nov 22, 2000 at 11:46 UTC
But, that's what I've done. The => does the same as the comma - unless I'm really missing something. I find it clearer to read that way.	[reply]