#!/usr/bin/perl

# Filename: cdir
# Author: G Ling Silva
# Date: January, 1996
# SYNOPSIS: cdir
# DESCRIPTION: Check file permission

# system 'clear';

chop($help = <<'EOP');

File Permission Check:

 a) Directory
 b) Change permission
 h) Help
 x) Exit


EOP

$prompt = 'cdir>';


#
# Main loop
#

print $help;
while (1) {
   print $prompt;
   if (($ans = substr(<STDIN>,0,1)) ne '') {    # Get command
      if ($ans eq 'a') {
         &get_dir;                              # Print directory
      }
      elsif ($ans eq 'b') {
         &mod_entries;                          # Modify file permission
      }
      elsif ($ans eq 'h') {
         print $help;                           # Print help message
      }
      elsif ($ans eq 'x') {
         die "Klart!\n";                        # Exit
      }
   }
}


#
# Get directory
#

sub get_dir {
   system 'ls -lF | more';
   return 0;
}


#
# Modify file mode
#

sub mod_entries {
   do {
      print "\nInput filename: ";
      chop ($filename = <STDIN>);                 # Get filename
      print "\n";
      if ($filename) {
         if (!(-e $filename)) {                   # Check if file exists
            warn "CDIR: $filename not found!\n";
         }
         else {                                   # Process entry
            open (LS, "/bin/ls -l $filename |") || warn "CDIR: Can't run ls\n";
            $inmode = <LS>;
            $inmode =~ /^(\S+)/;                  # Get 1st word from ls output
            $inmode = $1;
            close(LS);
            print "Actual permissions for filename $filename: $inmode\n";
            $outmode = 0;
            print "Permissions for USER:\n";
            $outmode |= (&get_mode_mask << 6); # Shift 1st digit into position
            print "Permissions for GROUP:\n";
            $outmode |= (&get_mode_mask << 3); # Shift 2nd digit into postion
            print "Permissions for OTHER:\n";
            $outmode |= &get_mode_mask;        # Add last digit
            printf ("New permission: %lo\n", $outmode);
            chmod $outmode, $filename;         # Change actual permission
         }
      }
   } while ($filename ne '');                  # Until null entry
   return 0;
}


#
# Get permission mask
#

sub get_mode_mask {
   $omode = 0;
   print "Readable (y/N): ";
   if (substr(<STDIN>, 0, 1) =~ /[Yy]/) {
      $omode |= 4;
   }
   print "Writable (y/N): ";
   if (substr(<STDIN>, 0, 1) =~ /[Yy]/) {
      $omode |= 2;
   }
   print "Executable (y/N): ";
   if (substr(<STDIN>, 0, 1) =~ /[Yy]/) {
      $omode |= 1;
   }
   return $omode;
}