PHP

Compress and Decompress Hex String

See more Compression Examples

Imagine we have data represented as a hex string. This example demonstrates how to decode, compress, and re-encode to a smaller hex string representing the compressed data. An even better choice is to re-encode to a more compact encoding such as base64.

Note: This example requires Chilkat v9.5.0.66 or greater.

Chilkat2 PHP

<?php

use Chilkat2\BinData;
use Chilkat2\Compression;

// This example assumes the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

$strHex = '54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A0D0A';

$compress = new Compression();
$compress->Algorithm = 'deflate';

$binDat = new BinData();
// Load the hex string into a BinData object.
// This decodes the hexidecimal. The decoded bytes will be contained in the BinData.
$binDat->AppendEncoded($strHex, 'hex');

// Compress the BinData.
$compress->CompressBd($binDat);

// Get the compressed data in hex format:
$compressedHex = $binDat->GetEncoded('hex');
echo "compressed hex:\n";
echo $compressedHex, "\n";

// The compressed hex is: 0BC94855282CCD4CCE56482ACA2FCF5348CBAF50C82ACD2D484D51C82F4B2D522801CAE72456552AA4E4A7EBF172850C61E5BC5C00

// Even better, get the compressed data in base64 format:
// (base64url and modbase64 are other valid choices...)
$compressedBase64 = $binDat->GetEncoded('base64');
echo "compressed base64:\n";
echo $compressedBase64, "\n";

// The compressed base64 is: C8lIVSgszUzOVkgqyi/PU0jLr1DIKs0tSE1RyC9LLVIoAcrnJFZVKqTkp+vxcoUMYeW8XAA=

// Now decompress:
$binDat->Clear();
$binDat->AppendEncoded($compressedHex, 'hex');
$compress->DecompressBd($binDat);

$decompressedHex = $binDat->GetEncoded('hex');
echo "decompressed hex:\n";
echo $decompressedHex, "\n";

// The output is the original hex string:
// 54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A54686520717569636B2062726F776E20666F78206A756D706564206F76657220746865206C617A7920646F672E0D0A0D0A