PPMD String Compression

Demonstrates string compression using PPMD.

The functionality in this example is available in pre-release only:

Chilkat Module for Perl 5.8.* (Pre-Release)

Chilkat Module for Perl 5.10.* (Pre-Release)

use chilkat;

$compress = new chilkat::CkCompression();

#  Any string argument automatically begins a 30-day trial.
$success = $compress->UnlockComponent("30-day trial");
if ($success != 1) {
    print "Compression component unlock failed" . "\n";
    exit;
}

$compress->put_Algorithm("ppmd");

#  Create a long string to compress.
$strData = "abcdefg1122334455667788";
$strData = $strData . "\r\n";
for ($i = 0; $i <= 99; $i++) {
    $strData = $strData . "abcdefg1122334455667788";
    $strData = $strData . "\r\n";
}

#  Depending on the programming language, the string
#  may be Unicode.  Tell the component to convert to
#  ansi (1-byte/char) prior to compression:
$compress->put_Charset("ansi");

#  Compressed data is binary, meaning that all byte values
#  from 0 to 255 are possible.  The result would not be
#  a printable string.  To receive a printable string (us-ascii),
#  the resultant compressed data should be encoded using
#  an encoding such as base64.  Set the EncodingMode
#  property to determine the output encoding:
#  (Valid choices are "base64", "hex", "url", and others)
$compress->put_EncodingMode("base64");

#  Note: Base64 encoding expands the compressed data by
#  4/3rds because each 3 bytes of binary data are represented
#  by 4 printable chars.  Hex, for example, doubles the output
#  size because each byte is represented by 2 printable chars.

#  PPMD compress the string:

$compressedStr = $compress->compressStringENC($strData);
if ($compressedStr eq null ) {
    print $compress->lastErrorText() . "\n";
    exit;
}

#  Display the compressed string.
#  The result will be:
#  ec8YZ5vk9za18d0plwuV7R65em9OZge9gJXht/QAAAAAAAAAABNOZQAAKw==
print $compressedStr . "\r\n";

#  Decompress back to the original:

$strOriginal = $compress->decompressStringENC($compressedStr);

#  Display the uncompressed original:
print "--- Original ---" . "\r\n";
print $strOriginal . "\r\n";