How about this: 
# Prepend $pwd as necessary
@p=();
foreach (split("/", $path)) {
  pop @p, next if $_ eq '..';
  next if $_ eq '.';
  push @p, $_;
}
$path=join("/", @p);

[download]
It is clearer, in my opinion, but considerably slower: 
Benchmark: timing 1000 iterations of Mikfire, Zamboni...
   Mikfire:  1 wallclock secs ( 0.47 usr +  0.00 sys =  0.47 CPU)
   Zamboni:  4 wallclock secs ( 3.23 usr +  0.00 sys =  3.23 CPU)

[download]
As given, your last solution produces double diagonals sometimes. For the string '/home/zamboni/tmp/../lib/./tex/..' it produces '/home/zamboni//lib//'. The solution is to match a second optional diagonal after the (\.)?, like this: 
while ( $path =~ s#(/[^/]+)?/\.(\.)?/?#defined($2) ? "/" : "$1/"#e ) {
+;}

[download]

--ZZamboni

In reply to Re: Normalized directory paths by ZZamboni
in thread Normalized directory paths by mikfire

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