There are a lot of ways:

1) using system:

system("notepad.exe /p \"filename.txt\"");
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Or with Win Me and NT4+ should be also:

system("print [/D:device] [[drive:][path]filename[...]]");
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2) Using a method inspired by Printer.pm by Stephen Patterson:

$|=1;
my $i=0;
while (-e "$ENV{TEMP}\\printer-$i") { ++$i; }

my $spoolfile =  "$ENV{TEMP}\\printer-$i";
my $data="String to print";
$data.="\f";

open SPOOL, ">$spoolfile";
print SPOOL $data;
close SPOOL;
system("copy /B $spoolfile LPT1:");
unlink $spoolfile;
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3) code from here :

open( LPT, "+>LPT1" ) or die "Can't access printer: $!";
print LPT "Text to print\n\f";
close (LPT);
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4) code from Mike Solomon: (see also Article ID: Q154078 on MSDN)

#! perl -w
use strict;
use Win32::API;

&print("foo");

sub print {

    my $text=$_[0];

    my $PrintDialog =  new Win32::API('comdlg32', 'PrintDlg', ['P'],
'N');
    my $GlobalLock = new Win32::API('kernel32', 'GlobalLock', ['N'],
'N');
    my $GlobalFree =  new Win32::API('kernel32', 'GlobalFree', ['N'],
'N');
    my $OpenPrinter = new Win32::API('winspool.drv', 'OpenPrinter',
['P','P','P'], 'N');
    my $StartDocPrinter = new Win32::API('winspool.drv',
'StartDocPrinter', ['N','N','P'], 'N');
    my $StartPagePrinter = new Win32::API('winspool.drv',
'StartPagePrinter', ['N'], 'N');
    my $WritePrinter =     new Win32::API('winspool.drv',
'WritePrinter',  ['N','P','N','P'], 'N');
    my $EndPagePrinter =   new Win32::API('winspool.drv',
'EndPagePrinter',  ['N'], 'N');
    my $EndDocPrinter =    new Win32::API('winspool.drv',
'EndDocPrinter', ['N'],  'N');
    my $ClosePrinter =     new Win32::API('winspool.drv',
'ClosePrinter', ['N'],  'N');
    my $GetLastError =     new Win32::API('kernel32', 'GetLastError',
[],  'N');
    my $FormatMessage = new Win32::API('kernel32',
'FormatMessage',['N','P','N','N','P','N','P'], 'N');

    my $pd = pack("Lx16Lx42", 66, 0x10010C);
    unless ($PrintDialog->Call($pd)) {
            return 0;
    }

    my ($devmode) = unpack("x8L", $pd);
    # devmode is a handle to movable global memory
    my $handle = $devmode;
    # get actual memory pointer
    unless ($devmode = $GlobalLock->Call($handle))
{ShowError('GlobalLock')};
    # get perl to use long integer as a pointer
    $devmode = unpack('P156', pack('L', $devmode));
    # release the global memory
    unless ($GlobalFree->Call($handle) == 0) {ShowError('GlobalFree')}
+;
    # these strings are blank padded
    my ($devicename) = unpack('A32', $devmode);

    $devicename .= "\0";
    my $hprinter = pack('x4');
    # RAW mode
    my $datatype = "RAW\0";
    # devmode not passed in pdefaults
    # user selected paper/orientation/duplex have no effect in RAW mod
+e
    # defaults set at printer will be used
    my $pdefaults = pack('px4L', $datatype, 0x8); # PRINTER_ACCESS_USE
    $OpenPrinter->Call($devicename, $hprinter, $pdefaults) or
ShowError('OpenPrinter');
    $hprinter = unpack('L', $hprinter);
    
    # name of document in print manager display
    # this won't be there very long unless the printer is off or busy
with another job
    my $docname = "Win32::API print test\0";
    my $docinfo = pack("px12", $docname);
    $StartDocPrinter->Call($hprinter, 1, $docinfo) or
ShowError('StartDocPrinter');
    $StartPagePrinter->Call($hprinter) or ShowError('StartPagePrinter'
+);
    
    my $written = pack('x4');
    $text .= "\f";
    my $len = length $text;
    $WritePrinter->Call($hprinter, $text, $len, $written) or
ShowError('WritePrinter');
    # one canvas per sheet, next postscript would start new sheet

    $EndPagePrinter->Call($hprinter) or ShowError('EndPagePrinter');
    $EndDocPrinter->Call($hprinter) or ShowError('EndDocPrinter');
    $ClosePrinter->Call($hprinter);
}
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5) also this:

$file="foo.txt";
print `type $file > lpt1:`;
print `echo "\f" > lpt1:`;
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6) code from Indy Singh:

if (-e "$ENV{'WINDIR'}/System32/mshtml.dll") {
   $dll = "$ENV{'WINDIR'}/System32/mshtml.dll";
} else {
   $dll = "$ENV{'WINDIR'}/System/mshtml.dll";
}

#note: can't use this to print multiple files
system("rundll32.exe $dll,PrintHTML $outfile");
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