my @dirs; my @files;
for (readdir DIR) {
  next if $_ eq "." or $_ eq "..";
  if (-d "$base/$_") {
    push @dirs, $_;
  } else {
    push @files, $_;
  }
}
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-- Randal L. Schwartz, Perl hacker

Run that code on /dev and it will get seriously wrong results.

A file isn't just anything that is not a directory.

foreach my $file ( readdir(DIR) ) {
    push @dirs, $file if -d "$base/$file"
                         and $file ne "."
                         and $file ne "..";
    push @files, $file if -f "$base/$file";
}
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No need for a void map.

for (readdir DIR) {
  next if $_ eq "." or $_ eq "..";
  next unless -d "$base/$_" or -f _;
  push @{ -d _ ? \@dirs : \@files }, $_;
}
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Update: Excellent point by particle++. Code updated accordingly.

Makeshifts last the longest.

I quite like that one. I came close to that but missed (actually, simply wasn't aware of) the @{\@array) 'trick'.

However (you knew that was coming right?), as I can do:

my (@a1,@a2) = ([1,2,3],[3,2,1]);
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Update: the above line doesn't work after all

I had tried:

my (@a1,@a2) = ([1,2,3,4,5,6,7],[7,6,5,4,3,2,1]);
print Dumper(@a1), Dumper(@a2);
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which gave:

$VAR1 = [
          1,
          2,
          3,
          4,
          5,
          6,
          7
        ];
$VAR2 = [
          7,
          6,
          5,
          4,
          3,
          2,
          1
        ];
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which certainly lookedlike it had worked! It was only after seeing this that I went back and added a couple of labels

print "a1\n", Dumper(@a1), "a2\n", Dumper(@a2);
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That I saw what tstock meant below.

Thanks tstock, I'll be more careful in future with my quick tests. (I agree about the loop/if being better too.)

end of update

Which personally I find a very clear yet concise way of declaring and initialising two arrays. It still seems as if something close to:

my ( @dirs, @files)= 
   ( @{-d}, @{-f} ) for (readdir DIR);
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could be possible if I could only get the syntactic sugar right!

This is only an exercise in my trying to understand arrays and list contexts etc. ie. Its essentially a purely academic excercise for late (for me) on a Sunday evening, and so not worthy of anyone's time unless they are also in play mode.

this code does not work -- !-d  !=  -f!

to implement this code properly, you must test for both -d, and -f, and ignore the rest. add next unless -d $_ or -f _; before the push statement and you'll have what you're looking for.

for (readdir DIR) {
  next if $_ eq '.' or $_ eq '..';
  next unless -d $base . '/' . $_ or -f _;
  push @{ -d $base . '/' . $_ ? \@dirs : \@files }, $_;
}
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Update: changes as per Screamer

Update 2: for more info on filetests, see -X under perlfunc

~Particle *accelerates*

for $item @list {

  next if definite failure condition
    
  action if most likely condition
  action if next most likely condition
  etc.

  default action
}
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for (readdir DIR) {

  next if $_ eq '.' || $_ eq '..';

  push (@files,$_) && next if -f $base/$_;
  push (@dirs,$_) && next if -d $base/$_;

  # default to no operation
}
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--
Steve Marvell