dear fellow monks,

why does ... 

opendir(D, "test");
while ( $file = readdir(D) ) 
{
    print "$file is ";
    print ($file ? "true" : "false");
    print "\n";
}

[download]

... work correctly, even for a filename like "0" that evaluates to false in boolean context? (see here for full code + output)

This seems to be an extreme case of "do-what-i-mean". I find it a little scary, because I don't know how it does what I mean ;-)

p.s.
I hit on this while doing research for my talk on php an perl at this years german perl workshop. the php counterpart looks appalingly complicated: 

# this is php, not perl!
$d = opendir('test);
while (false !== ($file = readdir($d))) { 
    print "$file is ";
    print ($file ? "true" : "false");
    print "\n";
}

[download]

see also the php documentation. 

--
Brigitte    'I never met a chocolate I didnt like'    Jellinek
http://www.horus.com/~bjelli/         http://perlwelt.horus.at

In reply to readdir and while - magic? by bjelli

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