#!/usr/bin/perl  -Wl
sub doit {
    $! = undef;
    open FH, shift or die "open failure: $!\n";
    print "After successful open : $!";
    1 while readline FH;
    print "After successful read : $!";
}
doit $0, 5;   
doit $0, 6;  
doit $0, undef;

__END__
___output___
___linux___
After successful open : Inappropriate ioctl for device
After successful read : 
After successful open : Inappropriate ioctl for device
After successful read : 
After successful open : Inappropriate ioctl for device
After successful read :

$ perl -e 'print $]'
5.008008

$ uname -a
Linux cond0 2.6.17-10-386 #2 Fri Oct 13 18:41:40 UTC 2006 i686 GNU/Linux

$ cat /etc/issue
Ubuntu 6.10 \n \l

___windows___
Name "main::FH" used only once: possible typo at read.pl line 4.
After successful open :
After successful read : Bad file descriptor
After successful open :
After successful read : Bad file descriptor
After successful open :
After successful read : Bad file descriptor

$ perl -e "print $]"
5.008006

$ ver
Microsoft Windows [Version 5.2.3790]

$ type c:\boot.ini | perl -ne "print $1 if /\"(.*)\"/"
Windows NT 5.2(3790.srv03.SP1.rtm.050324-1447)