> -----Ursprüngliche Nachricht-----
> Von: Rafael Garcia-Suarez [mailto:[EMAIL PROTECTED]
> Gesendet: Montag, 5. September 2005 16:24
> An: Dintelmann, Peter
> Cc: perl5-porters@perl.org
> Betreff: Re: _ handle and sub _
> On 9/5/05, Dintelmann, Peter <[EMAIL PROTECTED]> wrote:
> > When a subroutine _ is defined it may "mask" the _ handle used
> > by file test operators.
> >
> > #!/opt/perl32/bin/perl
> >
> > use strict;
> > use warnings;
> >
> > sub _ { "/etc/hosts" }
> >
> > open my $f, "/dev/null" or warn $!;
> > stat $f or warn $!;
> >
> > print "size: ", -s _, "\n";
> >
> > In the last line sub _ is invoked and the script prints the size
> > of "/etc/hosts" instead of 0.
> >
> > However "-X *_" seems to get this right. Should we mention this in
> > perlfunc?
>
> I don't think so, since this behaviour is the same with any other
identifier.
Certainly, but _ is in main which may cause problems with modules.
Here is a simple example using File::Find which resembles the problem I
was originally debubbing.
#!/opt/perl32/bin/perl -l
use strict;
BEGIN { sub _ {1} }
use File::Find; # _ handle used in File::Find
my $cnt = 0;
find sub {$cnt++}, "/etc";
print $cnt; # 1 instead of 815 on my system
Replacing the _ handle with *_ in the module saved my day (do you think
we should patch File::Find?) which reminds me about the usage of
"local $_" in modules.
Though the choice of _ as a sub name may be problematic as pointed out
by MJD there is existing code which uses it already.
