Re^2: Redirect Subroutine Output

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

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Re^3: Redirect Subroutine Output by toolic (Bishop) on Aug 26, 2009 at 18:28 UTC
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");` [download]	[reply] [d/l] [select]

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Re^3: Redirect Subroutine Output
by toolic (Bishop) on Aug 26, 2009 at 18:28 UTC

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:

$_[0]

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