On Tue, 12 Jun 2001, Charles Lu <[EMAIL PROTECTED]> wrote,
> my $oldhandle=undef;
> if($user_input ne 'STDOUT') { #user specify output to a file
> open (OUT,">$temp.txt") or die "Can't open the file\n";
> $oldhandle = select OUT;
> }
>
> print "blah blah blah\n";
>
> select ($oldhandle) if(defined($oldhandle)); #restore STDOUT as default
>
> At this point I want to close my FileHandle (OUT) if it was open. My
> question is HOW do I check to see whether a filehandle(OUT) has been opened
> so I can explicitly close it with
One way,
print "sample 1\n";
my $want_out_file = shift;
my $fh = *STDOUT;
if ($want_out_file) {
open OUT, ">zzzfile" or die $!;
$fh = *OUT;
}
print $fh "output of sample 1\n";
close $fh if $want_out_file;
Another way,
print "\nsample 2\n";
put("to stdout");
open F, ">the-F-file" or die $!;
put("to the-F-file", \*F);
close F;
put("to zzzfile", 'zzzfile');
sub put {
my($text, $file) = @_;
my $fh = *STDOUT; # default output stream
my $opened;
if (defined $file) {
if (UNIVERSAL::isa($file, 'GLOB')) {
$fh = $file; # $file is already opened
} else {
local *OUT;
open OUT, ">$file" or die $!; # open the file ourself
$fh = *OUT; # new filehandle
++$opened; # mark it for later use.
}
}
print $fh "$text\n";
$opened && close $fh;
}
I'm sure there's more elegant way to do this.
__END__
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