#!/usr/bin/perl
use warnings;
use strict;

#########################################
# dlist.pl for binrev pc #6		#
# by: robf				#
# 					#
# returns directory listing similar to	#
# ls, with some sorting an display	#
# options.				#
# license: GPL				#
# 					#
# usage:  ./dlist.pl <path> [-Options]	#
# ------------------------------------	#
# use -? for help			#
#					#
#########################################

my $directory =
  "/home/robf/src/perl/pc6";    # debug,  release will read from $ARGV[];

### Global vars

my %file;
my %options;
my @output;

# my $directory;

###

### Main
getargs();
dirlist($directory);
sortfiles();
output();

###

### Argument handling

sub getargs {
    my $definedDir;
    foreach (@ARGV) {
        if ( $_ =~ m/^-([adhprs])$/ ) {
            $options{$1} = "1";
        }
        elsif ( $_ =~ m/^-S([ndts])$/ ) {
            $options{S} = $1;
        }
        elsif ( $_ =~ m/-\?/ ) {
            displayHelp();
            exit;
        }
        elsif ( $_ =~ m/^(-.*)$/ ) {
            die "option $1 is unknown please use -? for help\n";
        }
    }

}

sub displayHelp {
    print <<ENDHELP
usage:		$0 <directory> <options>
example:	$0 / -a -St
  -S<dnst>		[n]ame(default), [d]ate, [t]ype, [s]ize
  -s			display file sizes 
  -a			show all in output [size, permissions, date]
  -p			show permissions
  -d			show date modified
  -r			recursive list
  -h			show hidden files
ENDHELP
}

###

### Directory listing

sub dirlist {
    opendir( DIR, "$_[0]" ) || die "cannot open $_[0]: $!";
    my @readdir = readdir(DIR);
    close DIR;
    foreach (@readdir) {
        open( CURFILE, "$_" );
        next if ( $_ =~ m/^(\.|\.\.)$/ );
        next if ( $_ =~ m/^\..*/ && not( $options{a} || $options{h} ) );
        (
            $file{$_}{dev},   $file{$_}{ino},   $file{$_}{mode},
            $file{$_}{nlink}, $file{$_}{uid},   $file{$_}{gid},
            $file{$_}{rdev},  $file{$_}{size},  $file{$_}{atime},
            $file{$_}{mtime}, $file{$_}{ctime}, $file{$_}{blksize},
            $file{$_}{blocks},
          )
          = stat CURFILE;
        $file{$_}{ctimeHuman} =
          localtime( $file{$_}{ctime} );    # Human Readable Ctime
        $file{$_}{numPerms} =
          ( sprintf "%04o", $file{$_}{mode} & 07777 )
          ;                                 # Get numeric permissions from Mode
        if ( -f _ )                         # get the file type for each file.
        {
            $file{$_}{type} = "";
        }
        elsif ( -d _ ) {
            $file{$_}{type} = "<dir>";
        }
        elsif ( -l _ ) {
            $file{$_}{type} = "link";
        }
        else {
            $file{$_}{type} = "file type not known/handled at this time.";
        }
        close CURFILE;
    }
}

###

### Output options

sub outputopts {
    my $filename = shift;
    my $count    = shift;
    my $bytesize;
    my $metric;
    my $formattedSize = $file{$filename}{size};
    while ( $formattedSize > 1024 ) {
        $formattedSize /= 1024;
        $metric++;
    }
    if ( $metric == 0 ) {
        $bytesize = "B";
    }
    elsif ( $metric == 1 ) {
        $bytesize = "KB";
    }
    elsif ( $metric == 2 ) {
        $bytesize = "MB";
    }
    elsif ( $metric == 3 ) {
        $bytesize = "GB";
    }
    elsif ( $metric == 4 ) {
        $bytesize = "TB";
    }
    $formattedSize = sprintf( "%u", $formattedSize );

    if ( $options{a} ) {

        $output[$count] =~
s/(.*)/$file{$filename}{type}\t$formattedSize$bytesize\t$file{$filename}{numPerms} $file{$filename}{ctimeHuman}\t$1/;
        return;
    }
}

###

### Sort options

sub sortfiles {
    $options{S} = "n" unless $options{S};
    my $filename;
    my @filelist;
    my $count = 0;
    foreach $filename ( keys %file )    #
    {
        push @filelist, $filename;
    }
    if ( $options{S} eq "d" ) {
        print "sorting by date is unimplemented.\n";
    }
    elsif ( $options{S} eq "t" ) {
        print "sorting by type is unimplemented.\n";
    }
    elsif ( $options{S} eq "s" ) {
        print "sorting by size is unimplemented.\n";
    }
    elsif ( $options{S} eq "n" ) {
        @output = sort @filelist;
    }
    foreach (@output) {
        outputopts( $_, $count );
        $count++;
    }
}

###

### Final Output
sub output {
    foreach (@output) {
        print $_ . "\n";
    }
}
###