pad and unpad byte array

Demonstrates using the pad and unpad methods of CkByteArray.

Download Chilkat Perl Module

use chilkat;


$data_bytes = pack "C10", 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;
$data = new chilkat::CkByteData();
$data->append($data_bytes,10);

#  These are the padding options for the "pad" method:
#  0 = Each padding byte is the pad count (16 extra added if size is already a multiple of 16)
#  1 = Random bytes except the last is the pad count (16 extra added if size is already multiple of 16)
#  2 = Pad with random data. (If already a multiple of 16, no padding is added).
#  3 = Pad with NULLs. (If already a multiple of 16, no padding is added).
#  4 = Pad with SPACE chars(0x20). (If already a multiple of 16, no padding is added).

#  We'll pad to a block size of 16 bytes.
$blockSize = 16;

$paddingScheme = 0;

#  Pad, display the padded byte data, unpad, then re-display
$data->pad($blockSize,$paddingScheme);
print $data->getEncoded("hex") . "\r\n";
$data->unpad(16,$paddingScheme);
print $data->getEncoded("hex") . "\r\n";
print "----" . "\r\n";

$paddingScheme = 1;
#  Pad, display the padded byte data, unpad, then re-display
$data->pad($blockSize,$paddingScheme);
print $data->getEncoded("hex") . "\r\n";
$data->unpad(16,$paddingScheme);
print $data->getEncoded("hex") . "\r\n";
print "----" . "\r\n";

#  There is no unpadding with schemes 2,3, and 4
$data2_bytes = pack "C10", 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;
$data2 = new chilkat::CkByteData();
$data2->append($data2_bytes,10);
$paddingScheme = 2;
#  Pad and display the padded byte data
$data2->pad($blockSize,$paddingScheme);
print $data2->getEncoded("hex") . "\r\n";
print "----" . "\r\n";

#  There is no unpadding with schemes 2,3, and 4
$data3_bytes = pack "C10", 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;
$data3 = new chilkat::CkByteData();
$data3->append($data3_bytes,10);
$paddingScheme = 3;
#  Pad and display the padded byte data
$data3->pad($blockSize,$paddingScheme);
print $data3->getEncoded("hex") . "\r\n";
print "----" . "\r\n";

#  There is no unpadding with schemes 2,3, and 4
$data4_bytes = pack "C10", 0, 1, 2, 3, 4, 5, 6, 7, 8, 9;
$data4 = new chilkat::CkByteData();
$data4->append($data4_bytes,10);
$paddingScheme = 4;
#  Pad and display the padded byte data
$data4->pad($blockSize,$paddingScheme);
print $data4->getEncoded("hex") . "\r\n";
print "----" . "\r\n";