#! /usr/local/bin/perl

# resolve or abbreviate file path

# path -r path		resolve path (make it absolute and without symbolic links)
# path -a path		abbreviate path

sub resolve_path {
  local ($path) = $_[0];
  local ($_, $dir, $fil, $orig);
  $orig = $path;
  if ($path =~ m-/+$-) {
    $path = $`;
  };
  if ($path !~ m-/-) {
    $_ = `pwd`;
    chop;
    $path = "$_/$path";
  };
  $it = 0;
  while ( -l $path) {
    if ($path =~ m-^(.+)/([^/]*)$-) {
      $dir = $1;
    } else {
      $dir = '';
    };
    $path = readlink ($path);
    if ($path !~ m-^/-) {
      $path = "$dir/$path";
    };
    die "circular link $path" if $it++ > 40;
  };
  if ($path =~ m-^(.+)/([^/]*)$-) {
    $dir = $1;
    $fil = $2;
    $dir = &resolve_path ($dir);
    if ($fil eq '.') {
      $path = $dir;
    } elsif ($fil eq '..' && $dir =~ m-^(.*)/([^/]*)$-) {
      $path = $1;
    } elsif ($fil ne '..' || $dir ne '') {
      $path = "$dir/$fil";
    };
  };
  # print "\"$orig\" is \"$path\"\n";
  return $path;
}

sub abbrev_path {
  local ($path) = &resolve_path ($_[0]);
  if ($path =~ m+^/afs/lrz-muenchen.de/home/./+) {
    $path = "~$'";
  } elsif ($path =~ m+^/afs/lrz-muenchen.de/common/+) {
    $path = $';
  } elsif ($path =~ m+^/afs/lrz-muenchen.de/+) {
    $path = $';
  };
  if ($path =~ m+^([^/]*/).*(/[^/]*/\d*)$+) {
    return $1 . "\267\267\267" . $2;
  } elsif ($path =~ m+^([^/]*/[^/]*/).*(/[^/]*)$+) {
    return $1 . "\267\267\267" . $2;
  } else {
    return $path;
  };
}

if ($#ARGV == 1) {
  if ($ARGV[0] eq '-r') {
    print &resolve_path($ARGV[1]) . "\n";
  } elsif ($ARGV[0] eq '-a') {
    print &abbrev_path($ARGV[1]) . "\n";
  } else {
    die "incorrect options";
  };
} else {
  die "incorrect options";
};