How do you create a .gz file using PHP?

This code does the trick

// Name of the file we're compressing $file = "test.txt"; // Name of the gz file we're creating $gzfile = "test.gz"; // Open the gz file (w9 is the highest compression) $fp = gzopen ($gzfile, 'w9'); // Compress the file gzwrite ($fp, file_get_contents($file)); // Close the gz file and we're done gzclose($fp); 

Also, you could use php's wrappers, the compression ones. With a minimal change in the code you would be able to switch between gzip, bzip2 or zip.

$input = "test.txt"; $output = $input.".gz"; file_put_contents("compress.zlib://$output", file_get_contents($input)); 

change compress.zlib:// to compress.zip:// for zip compression (see comment to this answer about zip compression), or to compress.bzip2:// to bzip2 compression.

Simple one liner with gzencode():

gzencode(file_get_contents($file_name)); 

Here's an improved version. I got rid of all the nested if/else statements, resulting in lower cyclomatic complexity, there's better error handling through exceptions instead of keeping track of a boolean error state, some type hinting and I'm bailing out if the file has a gz extension already. It got a little longer in terms of lines of code, but it's much more readable.

/** * Compress a file using gzip * * Rewritten from Simon East's version here: * https://stackoverflow.com/a/22754032/3499843 * * @param string $inFilename Input filename * @param int $level Compression level (default: 9) * * @throws Exception if the input or output file can not be opened * * @return string Output filename */ function gzcompressfile(string $inFilename, int $level = 9): string { // Is the file gzipped already? $extension = pathinfo($inFilename, PATHINFO_EXTENSION); if ($extension == "gz") { return $inFilename; } // Open input file $inFile = fopen($inFilename, "rb"); if ($inFile === false) { throw new \Exception("Unable to open input file: $inFilename"); } // Open output file $gzFilename = $inFilename.".gz"; $mode = "wb".$level; $gzFile = gzopen($gzFilename, $mode); if ($gzFile === false) { fclose($inFile); throw new \Exception("Unable to open output file: $gzFilename"); } // Stream copy $length = 512 * 1024; // 512 kB while (!feof($inFile)) { gzwrite($gzFile, fread($inFile, $length)); } // Close files fclose($inFile); gzclose($gzFile); // Return the new filename return $gzFilename; } 

If you are looking to just unzip a file, this works and doesn't cause issues with memory:

$bytes = file_put_contents($destination, gzopen($gzip_path, r)); 

It's probably obvious to many, but if any of the program execution functions is enabled on your system (exec, system, shell_exec), you can use them to simply gzip the file.

exec("gzip ".$filename); 

N.B.: Be sure to properly sanitize the $filename variable before using it, especially if it comes from user input (but not only). It may be used to run arbitrary commands, for example by containing something like my-file.txt && anothercommand (or my-file.txt; anothercommand).

copy('file.txt', 'compress.zlib://' . 'file.txt.gz'); See documentation

Compress folder for anyone needs

function gzCompressFile($source, $level = 9) { $tarFile = $source . '.tar'; if (is_dir($source)) { $tar = new PharData($tarFile); $files = scandir($source); foreach ($files as $file) { if (is_file($source . '/' . $file)) { $tar->addFile($source . '/' . $file, $file); } } } $dest = $tarFile . '.gz'; $mode = 'wb' . $level; $error = false; if ($fp_out = gzopen($dest, $mode)) { if ($fp_in = fopen($tarFile, 'rb')) { while (!feof($fp_in)) gzwrite($fp_out, fread($fp_in, 1024 * 512)); fclose($fp_in); } else { $error = true; } gzclose($fp_out); unlink($tarFile); } else { $error = true; } if ($error) return false; else return $dest; }