#!/bin/perl
#
#  This is something I worked out when I wanted to do file/directory exists tests
#  for things in AFS.  With the Perl we have (5.05_003), the normal -f/-d tests
#  always return true for AFS objects.  So I thought I would give stat a try.
#
#  Given that nada does not exist, and these do,
#    drwxr-xr-x   3 jasper   system      4096 Dec 14 14:35 bin
#    lrwxr-xr-x   1 jasper   staff          3 Dec 20 14:24 junk.dlink -> bin
#    -rwxr-xr-x   1 jasper   staff       4219 Dec 20 16:48 stat
#    lrwxr-xr-x   1 jasper   staff          7 Dec 20 14:49 junk.flink -> test.pl
#    lrwxr-xr-x   1 jasper   staff          4 Dec 20 14:59 junk.nada -> nada
#    crw-rw-rw-   1 root     system     2,  2 Dec 20 16:48 /dev/null
#    srwxrwxrwx   1 root     system         0 Nov 12 11:48 /tmp/.PMDV1
#
# Then calling this script like so,
#    stat bin junk.dlink stat junk.flink nada junk.nada /dev/null /tmp/.PMDV1
# returns
#               Name                 stat[3]-oct  stat[3]-dec  Fifth-oct  Fifth-dec  >> 12  
#    ==============================  ===========  ===========  =========  =========  =====  
#             bin is a directory           40755       16877       40000      16384      4 
#      junk.dlink is a link                40755       16877       40000      16384      4 
#            stat is not there                 0           0           0          0      0 
#      junk.flink is a link                    0           0           0          0      0 
#            nada is not there                 0           0           0          0      0 
#       junk.nada is a link                    0           0           0          0      0 
#       /dev/null is something else        20666        8630       20000       8192      2 
#     /tmp/.PMDV1 is something else       140777       49663      140000      49152     12
#
# Note that when using stat, there is no way to differientiate
#   - between a directory and a link to a directory,
#   - between a file and a link to a file,
#   - nor between something that doesn't exist and a link to something that doesn't exist.
# Appartently, stat follows links.
#
# I didn't want to live with these limitations, so I wound up coding my own ls -ld command
# and parsing the output.

  chdir();          # Start in my own home directory (of whichever ID I'm running as)

print "           Name                 stat[3]-oct  stat[3]-dec  Fifth-oct  Fifth-dec  >> 12  \n";
print "==============================  ===========  ===========  =========  =========  =====  \n";

while (@ARGV) {
  $thing=shift @ARGV;

  $ls=`ls -ld $thing 2>/dev/null`;
  if ($? >> 8) {
    $ls = "not there";
  } elsif (substr($ls,0,1) eq "d") {
    $ls = "a directory";
  } elsif (substr($ls,0,1) eq "-")  {
    $ls = "a file";
  } elsif (substr($ls,0,1) eq "l")  {
    $ls = "a link";
  } else {
    $ls = "something else";
  } 

  my (undef,undef,$mymode) = stat($thing);
  $mymode1= $mymode & 07770000;            # The fifth octal digit.
  $mymode2= $mymode >> 12;                 # Drop off the four low-order octal digits.
  printf "%12s is %-14s %12o %11d %11o %10d %6d \n", $thing, $ls, $mymode, $mymode, $mymode1, $mymode1, $mymode2;
}