For the uninitiated, there's an OO interface to the filehandles in Perl. All you do is use IO::Handle and at the expense of a mere *cough* few thousand lines of Perl code, you can replace non-OO access to filehandles:

open(my $foo,'<+ /dev/null');
#old
select($foo); $|=1; select(STDOUT);
print $foo "|<3wl! 31337 d00d!";
printf $foo "%.02f", $money;
$fd = fileno $foo;
read($foo, $input, 1024) unless eof $foo;
@stats = stat $foo;
close $foo;
#new
$foo->autoflush(1);
$foo->print("|<3w1! 0bj3ct 0r13nt3d f1l3h4ndl3z! l33t!");
$foo->printf("%.02f", $money);
$fd = $foo->fileno;
$foo->read($input, 1024) unless $foo->eof;
@stats = $foo->stat;
$foo->close;
[download]

Everybody back with me? Good.

Now, some people may be familiar with this nifty oneliner, that demonstrates the nature of the magic by which Perl associates filehandles with the IO::Handle package:

$ perl -le 'STDIN->close()'
Can't locate object method "close" via package "IO::Handle" at -e line
+ 1.
[download]

I've known about this problem, but something occurred to me today that reveals a serious issue with this magic. Please read on, I'd like to know if anyone agrees with me.

• perl -le '{package STDIN;sub close{print "case closed"}} STDIN->close(
  +)'
  [download]

  According the normal rules of engagement, this should invoke STDIN::close() as a method. People understanding the problem in 347618 will know his right away.

  Instead, the error "can't find method 'close' in IO::Handle" occurs, indicating that Perl is actually trying to treat the bareword STDIN as a bareword filehandle first, and as a package name second.

  While that may not be 100% optimal, the fact that filehandles have no identifying sigil makes this a necessary evil. So, I took it one step further.

• perl -le '{package STDIN;sub close{print "case closed"}} "STDIN"->clos
  +e()'
  [download]

  Again, I get "can't find method 'close' via IO::Handle", instead of "case closed". I guessed that Perl was trying harder to do the filehandle thing than I thought.

• perl -le '{package STDIN;sub close{print "case closed"}}my $foo="STDIN
  +"; $foo->close()'
  [download]

  Still IO::Handle.

  Perl is apparently trying to treat $foo as a symbolic reference to *STDIN, and doing the filehandle thing.

  I finally get to the real kicker:

• perl -Mstrict -Wle '{package STDIN;sub close{print "case closed"}}my $
  +foo="STDIN"; $foo->close()'
  [download]

  Lo and behold:

  Can't locate object method "close" via package "IO::Handle" at -e line 1.
  

Comments?

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         {}cd;print lc
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