in reply to Storing open filehandles in a hash

while (<>) {
   defined $fhs{$conn}
      or open($fhs{$conn}, '>', "conn-$conn")
         or die("Unable to create file conn-$conn: $!\n");

   print { $fhs{$conn} } $_;
}

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Re^2: Storing open filehandles in a hash
by kovacsbv (Novice) on Nov 20, 2008 at 14:59 UTC
    Can you shed some light on what the braces around $fhs{$conn} do in this case? It must have something to do with the file handle and print string being space separated, but I've been wondering for a while why we need those if we're using anything more complex than $variable_name but don't otherwise.
[reply]

      See the last paragraph of print's documentation.

      To keep the parser sane, print is very limited as to what it can accept for the file handle argument. It accepts a scalar variable ($fh) or a bare word (FH), and that's probably it unless you wrap the expression in curlies. Inside the curlies can be any Perl expression, including the a hash lookup as desired by the OP. 

      print { $fh } ...;
print $fh ...;     # Shorthand

print { FH } ...;
print FH ...;      # Same thing, but also works under strict 'vars'.

print { *FH                    } ...;
print { $a[$i]                 } ...;
print { $h{$k}                 } ...;
print { $o->get_fh()           } ...;
print { $e ? *STDERR : *STDOUT } ...;
etc.

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