Sun751 has asked for the wisdom of the Perl Monks concerning the following question:

my directory holds another directory name "p17" and I am doing following to read that directory, 
    my @a;
    my $dir = "/and/evel/aap/list/60";
    opendir(PATCH, $dir) || die "Unable to open $dir ";
    @a = readdir(PATCH);
    print "@a\n";
    closedir(PATCH);
    exit;

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After running above code I am getting following values in @a (array), 0 '.' 1 '..' 2 'p17' but I am suppose to get just p17, Have I done any thing wrong, can any one suggest me how can I get just another directory(p17)name???

Replies are listed 'Best First'.
Re: Reading Directory
by moritz (Cardinal) on Jul 14, 2009 at 08:03 UTC
    On Unix, every directory contains the directory . which is a reference to itself, and .., which is a reference to the parent directory. If you don't want to consider those, filter them out from the array.

    (Note that "reference" is a bit vague, I think it's more like a hard link, but I'm not entirely sure).

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      See a tutorial I just ran across, especially section 6.1.1.3 and 6.1.3. It seems to be a reasonable description.

      --MidLifeXis

      The tomes, scrolls etc are dusty because they reside in a dusty old house, not because they're unused. --hangon in this post

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Re: Reading Directory
by ELISHEVA (Prior) on Jul 14, 2009 at 08:44 UTC

    Take a look at File::Spec's no_upwards method. It lets you (portably) skip the dot directories:

    use strict;
use warnings;
use File::Spec;

my @x;
opendir(DIR, $dir) or die "Can't open directory $dir: $!";
eval { @x = File::Spec->no_upwards(readdir(DIR)); };
closedir(DIR);
print "@x\n";

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    Best, beth

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Re: Reading Directory
by Anonymous Monk on Jul 14, 2009 at 08:00 UTC
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Re: Reading Directory
by tokpela (Chaplain) on Jul 14, 2009 at 09:25 UTC

    I would also add that for scalability you should always iterate over a directory as opposed to pushing all of the filenames into an array.

    I would also use a lexical directory handle. 

    my $dir = "/and/evel/aap/list/60";

opendir(my $d, $dir) || die "Unable to open $dir ";

while (my $filename = readdir($d)) {

   # removes . and ..
   next if ($filename =~ /^\.+$/); 

   my $filepath = "$dir/$filename";

   .....

}

closedir($d);

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Re: Reading Directory
by ropey (Hermit) on Jul 14, 2009 at 11:10 UTC

    Or use grep to filter the directory

     @a = grep {$_ !~ /^\.{1,2}$/} readdir(PATCH);

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      Hi there your grep seems to work but can you make me understand how?, I am not getting this "!~" business. suggestion please, Cheers
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        I am not getting this "!~" business
        From Binding Operators:
        Binary "!~" is just like "=~" except the return value is negated in the logical sense.
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