unzip

source of perl for linux application,

use strict;
use warnings;

use File::Path;
use File::Basename;
use IO::File;
use IO::Uncompress::RawInflate qw(:all);


die "Usage: zipcat file\n" 
    if @ARGV != 1 ;

my $file = $ARGV[0] ;

my $fh = new IO::File "<$file"
            or die "Cannot open '$file': $!\n";

while ()
{
    my $FIXED_HEADER_LENGTH  = 30 ;
    my $sig;
    my $buffer;

    my $x ;
    ($x = $fh->read($buffer, $FIXED_HEADER_LENGTH)) == $FIXED_HEADER_LENGTH 
        or die "Truncated file top: $x $!\n";

    my $signature = unpack ("V", substr($buffer, 0, 4));

    last unless $signature == 0x04034b50;

    my $compressedMethod   = unpack ("v", substr($buffer, 8, 2));
    my $compressedLength   = unpack ("V", substr($buffer, 18, 4));
   #my $uncompressedLength = unpack ("V", substr($buffer, 22, 4));
    my $filename_length    = unpack ("v", substr($buffer, 26, 2)); 
    my $extra_length       = unpack ("v", substr($buffer, 28, 2));

    warn "Compressed Length $compressedLength\n";
    my $filename ;
    $fh->read($filename, $filename_length) == $filename_length 
        or die "Truncated file\n";

    $fh->read($buffer, $extra_length) == $extra_length
        or die "Truncated file\n";

    if ($compressedMethod != 8 && $compressedMethod != 0)
    {
        warn "Skipping file '$filename' - not deflated $compressedMethod\n";
        $fh->read($buffer, $compressedLength) == $compressedLength
            or die "Truncated file\n";
        next;
    }

    next if $compressedLength == 0;

    warn "Writing file '$filename' $compressedMethod\n";

    #mkpath dirname $filename;

    #rawinflate $fh  => $filename,
    rawinflate $fh  => '-',
        Transparent => 1,
        InputLength => $compressedLength
      or die "Error uncompressing $file [$filename]: $RawInflateError\n"  ;
}

sub decodeLocalFileHeader
{
    my $buffer = shift ;
}