Re: Is there any way to override "file test operator"?

You can overload the operator with the overload pragma, although this only works if your package is being used as a class. Also only works on Perl v5.12 or later. Example:

package MyFileTest;

use overload (
    '-X' => \&myfiletest,
);

sub new {
    ...
}

...

package main;

my $file = MyFileTest->new($filename);
if(-f $file){
    ...
}
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See also the filetest pragma.

Comment on Re: Is there any way to override "file test operator"? Download Code

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Re^2: Is there any way to override "file test operator"? by Anonymous Monk on Aug 09, 2011 at 07:55 UTC
Hmm, then this should also work, but it doesn't #!/usr/bin/perl -- BEGIN { use IO::File; package IO::Handle; use overload '-X' => sub { warn 'abracadabra'; stat@_; }; *IO::Handle::stat = sub { warn "hi walter"; stat(@_); }; } open my($fh), '<', __FILE__; print '-e ', -e $fh, "\n"; print '-f ', -f $fh, "\n"; print '-d ', -d $fh, "\n"; print 'stat ', stat $fh, "\n"; print $fh, "\n"; close $fh; print "$_\n" for keys %INC; __END__ -e 1 -f 1 -d stat 00332061000745131287651313128765131312876169 GLOB(0x3f8adc) warnings/register.pm XSLoader.pm IO/Handle.pm SelectSaver.pm IO/Seekable.pm warnings.pm Fcntl.pm IO.pm Symbol.pm Carp.pm File/Spec/Unix.pm strict.pm Exporter.pm vars.pm File/Spec.pm IO/File.pm overload.pm File/Spec/Win32.pm [download]	[reply] [d/l]

Replies are listed 'Best First'.

Re^2: Is there any way to override "file test operator"?
by Anonymous Monk on Aug 09, 2011 at 07:55 UTC

#!/usr/bin/perl --
BEGIN {
    use IO::File;
    package IO::Handle;
    use overload '-X' => sub {
        warn 'abracadabra';
        stat@_;
    };
    *IO::Handle::stat = sub { warn "hi walter"; stat(@_); };
    
}

open my($fh), '<', __FILE__;
print '-e ', -e $fh, "\n";
print '-f ', -f $fh, "\n";
print '-d ', -d $fh, "\n";
print 'stat ', stat $fh, "\n";
print $fh, "\n";
close $fh;
print "$_\n" for keys %INC;
__END__
-e 1
-f 1
-d
stat 00332061000745131287651313128765131312876169
GLOB(0x3f8adc)
warnings/register.pm
XSLoader.pm
IO/Handle.pm
SelectSaver.pm
IO/Seekable.pm
warnings.pm
Fcntl.pm
IO.pm
Symbol.pm
Carp.pm
File/Spec/Unix.pm
strict.pm
Exporter.pm
vars.pm
File/Spec.pm
IO/File.pm
overload.pm
File/Spec/Win32.pm
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