Re: how do I write directly to a file

Perl uses buffering on its filehandles; data is cached and written in 4K chunks. To turn that off, set the file handle to auto flush;

use IO::Socket;

@colors = qw(pink yellow blue green);

open(COLORS, ">>colors.txt") or die $!;

# turn off stdio buffering on COLORS
COLORS->autoflush(1);

foreach $color (@colors){
    print COLORS "$color\n";
    print "sending $color to File\n";
}

while (<STDIN>) {
    chomp;
    exit if ($_ eq "quit");
    print COLORS $_;
}
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Re: Re: how do I write directly to a file by davorg (Chancellor) on Jun 07, 2001 at 19:37 UTC
The other way to turn off buffering is to set the `$\|` variable to a true value. This effects the currently selected default output filehandle (generally `STDOUT`) but you can change it on other filehandles like this: `my $fh = select COLORS; $\|++; select $fh;` [download] or in slightly more scarey code, like this: `select((select(COLORS), $\| = 1)[0]);` [download] So you can see why the IO::Socket method is preferred :) -- <http://www.dave.org.uk> Perl Training in the UK <http://www.iterative-software.com>	[reply] [d/l] [select]

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Re: Re: how do I write directly to a file
by davorg (Chancellor) on Jun 07, 2001 at 19:37 UTC

The other way to turn off buffering is to set the $| variable to a true value. This effects the currently selected default output filehandle (generally STDOUT) but you can change it on other filehandles like this:

my $fh = select COLORS;
$|++;
select $fh;
[download]

or in slightly more scarey code, like this:

select((select(COLORS), $| = 1)[0]);
[download]

So you can see why the IO::Socket method is preferred :)

http://www.dave.org.uk

Perl Training in the UK <http://www.iterative-software.com>

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