The compression level (compflags) option is, generally speaking, an integer value between 0 and 9. The behavior of the system depends on the selected method and the value of compflags and can sometimes be not you expected.
The result below is from PHP 8.1 on Windows platform and may possibly be different on other systems or versions:
- for the CM_DEFAULT method, always CM_DEFLATE is used with level 9, regardless of what you put as compflags,
- for the CM_STORE method, for compflags 0-9 you get the same result, which is obvious because the method itself means "no compression at all". However, for compflags>9, surprisingly the CM_DEFLATE method is used instead with compression level 9.
- for CM_DEFLATE method, 1 means the fastest and weakest compression, while 9 - the slowest and strongest one. compflags=0 and compflags>9 works as it if were with compflags=9,
- for CM_BZIP2 method, 1 means the fastest and weakest compression, while 9 - the slowest and strongest one. compflags=0 works like compflag=9, and if you use compflags>9, the method will surprisingly switch to CM_DEFLATE level 9,
- for CM_XZ method, 0 means the fastest and weakest compression, while 9 - the slowest and strongest one. For compflags>9 the method surprisingly switch to CM_DEFLATE level 9.
ZipArchive::setCompressionName
(PHP 7, PHP 8, PECL zip >= 1.13.0)
ZipArchive::setCompressionName — Establecer el método de compresión de una entrada definida por su nombre
Descripción
Establecer el método de compresión de una entrada definida por su nombre.
Parámetros
-
name -
El nombre de la entrada.
-
method -
El método de compresión. Una de las constantes
ZipArchive::CM_*. -
compflags -
Nivel de compresión.
Valores devueltos
Devuelve true en caso de éxito o false en caso de error.
Ejemplos
Ejemplo #1 Añadir ficheros con diferentes métodos de compresión a un archivo
<?php
$zip = new ZipArchive;
$res = $zip->open('test.zip', ZipArchive::CREATE);
if ($res === TRUE) {
$zip->addFromString('foo', 'Un texto');
$zip->addFromString('bar', 'Otro texto');
$zip->setCompressionName('foo', ZipArchive::CM_STORE);
$zip->setCompressionName('bar', ZipArchive::CM_DEFLATE);
$zip->close();
echo 'ok';
} else {
echo 'fallo';
}
?>Ejemplo #2 Añadir fichero y establecer el método de compresión
<?php
$zip = new ZipArchive;
$res = $zip->open('test.zip', ZipArchive::CREATE);
if ($res === TRUE) {
$zip->addFile('foo.jpg', 'bar.jpg');
$zip->setCompressionName('bar.jpg', ZipArchive::CM_XZ);
$zip->close();
echo 'ok';
} else {
echo 'failed';
}
?>
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gajowy at agzeta dot pl ¶
1 year ago
