Re: Redirect Subroutine Output

[goeb]

You could write the sub the following way:

use warnings; use strict;
sub print_to {
    print {$_[0]} $_[1];
}
print_to (*STDOUT, "test stdout");
print_to (*STDERR, "test stderr");

[spickles]

goeb -

Why do I get the error 'scalar found where operator expected' if I omit the braces around the $_[0]? What are the braces doing and why aren't they required around the second element?

Regards,
Scott

[toolic]

From the docs for print:

Note that if you're storing FILEHANDLEs in an array, or if you're using any other expression more complex than a scalar variable to retrieve it, you will have to use a block returning the filehandle value instead:

I believe the braces define a block of code, and I believe $_[0] qualifies as an 'expression more complex than a scalar variable'. If you refactor the sub like this, then the braces around the FILEHANDLE are not needed:

use warnings; use strict;
sub print_to {
    my ($fh, $str) = @_;
    print $fh $str;
}
print_to (*STDOUT, "test stdout");
print_to (*STDERR, "test stderr");