gzuncompress
This is a short example of use gzwrite function.
<?php
function gzcompressfile($source,$level=false){
$dest=$source.'.gz';
$mode='wb'.$level;
$error=false;
if($fp_out=gzopen($dest,$mode)){
if($fp_in=fopen($source,'rb')){
while(!feof($fp_in))
gzwrite($fp_out,fread($fp_in,1024*512));
fclose($fp_in);
}
else $error=true;
gzclose($fp_out);
}
else $error=true;
if($error) return false;
else return $dest;
}
?>
the function gzcompressfile() compress a file 'data.csv' to 'data.csv.gz'. the function return false if error, and the new file name if it's ok.
gzwrite
(PHP 4, PHP 5)
gzwrite — Ausgabe in gz-komprimierte Dateien
Beschreibung
int gzwrite
( resource
$zp
, string $string
[, int $length
] )
gzwrite() schreibt den Inhalt von
string in die angegebene gz-Datei aus.
Parameter-Liste
-
zp -
Eine gz-Datei Resource. Diese muss gültig sein und auf eine Datei zeigen die erfolgreich mit gzopen() geöffnet wurde.
-
string -
Der auszugebende String.
-
length -
Die Anzahl unkomprimierter Bytes die ausgegeben werden soll. Wenn angegeben wird nach
lengthgeschriebenen Bytes ausstringabgebrochen wenn bis dahin das Ende des Strings nicht erreicht ist.Hinweis:
Beachten Sie das der magic_quotes_runtime Konfigurationsparameter ignoriert wird und keine Slashes aus
stringentfernt werden wenn der optionale Parameterlengthübergeben wird.
Rückgabewerte
Gibt die Anzahl der (unkomprimierten) Bytes zurück die auf den gegebenen gz-Stream ausgegeben wurden.
Beispiele
Beispiel #1 gzwrite() Beispiel
<?php
$string = 'Zu komprimierende Daten';
$gz = gzopen('somefile.gz','w9');
gzwrite($gz, $string);
gzclose($gz);
?>
add a note
User Contributed Notes
gzwrite - [6 notes]
Kioob ¶
9 years ago
Take Heed ¶
2 years ago
Read the description of gzwrite() very carefully. If the 'length' option is not specified, then the input data will have slashes stripped on systems where magic quotes are enabled. This is important information to know when compressing files.
<?php
$data = fread($fp, 5000);
gzwrite($fp2, $data, strlen($data));
?>
Is the correct way to avoid issues with magic quotes.
calmarius at nospam dot atw dot hu ¶
4 years ago
gz compression is often used with tar archives. Building tar archives is quite easy. Here is a code snipplet which can be used for building tar archives before compressing them to tar.gz.
<?php
//\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
// Adds file header to the tar file, it is used before adding file content.
// f: file resource (provided by eg. fopen)
// phisfn: path to file
// archfn: path to file in archive, directory names must be followed by '/'
//\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
function TarAddHeader($f,$phisfn,$archfn)
{
$info=stat($phisfn);
$ouid=sprintf("%6s ", decoct($info[4]));
$ogid=sprintf("%6s ", decoct($info[5]));
$omode=sprintf("%6s ", decoct(fileperms($phisfn)));
$omtime=sprintf("%11s", decoct(filemtime($phisfn)));
if (@is_dir($phisfn))
{
$type="5";
$osize=sprintf("%11s ", decoct(0));
}
else
{
$type='';
$osize=sprintf("%11s ", decoct(filesize($phisfn)));
clearstatcache();
}
$dmajor = '';
$dminor = '';
$gname = '';
$linkname = '';
$magic = '';
$prefix = '';
$uname = '';
$version = '';
$chunkbeforeCS=pack("a100a8a8a8a12A12",$archfn, $omode, $ouid, $ogid, $osize, $omtime);
$chunkafterCS=pack("a1a100a6a2a32a32a8a8a155a12", $type, $linkname, $magic, $version, $uname, $gname, $dmajor, $dminor ,$prefix,'');
$checksum = 0;
for ($i=0; $i<148; $i++) $checksum+=ord(substr($chunkbeforeCS,$i,1));
for ($i=148; $i<156; $i++) $checksum+=ord(' ');
for ($i=156, $j=0; $i<512; $i++, $j++) $checksum+=ord(substr($chunkafterCS,$j,1));
fwrite($f,$chunkbeforeCS,148);
$checksum=sprintf("%6s ",decoct($checksum));
$bdchecksum=pack("a8", $checksum);
fwrite($f,$bdchecksum,8);
fwrite($f,$chunkafterCS,356);
return true;
}
//\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
// Writes file content to the tar file must be called after a TarAddHeader
// f:file resource provided by fopen
// phisfn: path to file
//\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
function TarWriteContents($f,$phisfn)
{
if (@is_dir($phisfn))
{
return;
}
else
{
$size=filesize($phisfn);
$padding=$size % 512 ? 512-$size%512 : 0;
$f2=fopen($phisfn,"rb");
while (!feof($f2)) fwrite($f,fread($f2,1024*1024));
$pstr=sprintf("a%d",$padding);
fwrite($f,pack($pstr,''));
}
}
//\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
// Adds 1024 byte footer at the end of the tar file
// f: file resource
//\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/
function TarAddFooter($f)
{
fwrite($f,pack('a1024',''));
}
?>
repository at lamaresh dot net ¶
4 years ago
This function add a line to a .gz compressed file
<?php
function AppendLineGz($file,$string) {
if (file_exists($file)) {
$lines = gzfile($file);
$lines[count($lines)] = "$string\r\n";
$input=implode($lines);
} else {$input="$string\r\n";}
$gz = gzopen($file,'w9');
gzwrite($gz, $input);
gzclose($gz);
}
?>
Anonymous ¶
5 years ago
katzlbtjunk's method is certainly shorter, but it is unusable for anything except small files. It would try to load the whole file into memory, then create an entire compressed copy, and only then write it to disk. The other method given below will not exhaust memory like that.
katzlbtjunk at hotmail dot com ¶
5 years ago
How about this instead:
$s = file_get_contents('file.tar');
file_put_contents('file.tar.gz',gzencode($s,9));