#!/usr/bin/perl -w
    use strict;

    my @path = split /:/, $ENV{PATH};
    my %path_inodes;
    my @clean_path;

    for (@path) {
      next unless m#^/#;
      my ($dev,$ino) = stat;
      next unless defined $dev;
      my $key = "$dev $ino";
      if (exists $path_inodes{$key}) {
        print "warning: $_ is linked to $path_inodes{$key}\n";
        next;
      }
      $path_inodes{$key} = $_;
      push @clean_path, $_;
    }

    my %progs;

    ## print "clean path is @clean_path\n";

    for my $dir (@clean_path) {
      use DirHandle;
      my @files =
        sort grep !/^\.\.?$/,
        DirHandle->new($dir)->read;
      ## print "$dir: @files\n";
      for my $file (@files) {
        if (exists $progs{$file}) {
          print "$file in $dir is shadowed by $progs{$file}\n";
          next;
        }
        $progs{$file} = $dir;
      }
    }
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