gzwrite

(PHP 4, PHP 5)

gzwrite — Écrit dans un fichier compressé gzip

Description

int gzwrite ( resource $zp , string $string [, int $length ] )

gzwrite() écrit le contenu de la chaîne string dans le fichier compressé zp.

Liste de paramètres

zp: Le pointeur de fichier. Il doit être valide et doit pointer vers un fichier ouvert avec succès grâce à la fonction gzopen().
string: La chaîne à écrire.
length: Le nombre d'octets décompressés à écrire. Si fournie, l'écriture s'arrêtera après length (décompressé) octets écrits ou si la fin de la chaîne string est atteinte ; celui qui survient le premier.

Note:
Notez que si l'argument length est donné, alors l'option de configuration magic_quotes_runtime sera ignoré et aucun slash ne sera supprimé de la chaîne string.

Valeurs de retour

Retourne le nombre d'octets (décompressés) écrits dans le fichier gz donné.

Exemples

Exemple #1 Exemple avec gzwrite()


<?php
$string = 'Quelques informations à compresser';
$gz = gzopen('somefile.gz','w9');
gzwrite($gz, $string);
gzclose($gz);
?>

Voir aussi

gzread() - Lecture de fichier compressé binaire
gzopen() - Ouvre un fichier compressé avec gzip

readgzfile

gzuncompress

[edit] Last updated: Fri, 25 May 2012

add a note User Contributed Notes gzwrite

Take Heed 07-Nov-2010 12:50


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 05-Feb-2009 08:07


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 03-Feb-2009 10:37


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 27-Mar-2008 12:34


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 21-Feb-2008 11:24


How about this instead:

$s = file_get_contents('file.tar'); 

file_put_contents('file.tar.gz',gzencode($s,9));

Kioob 13-Aug-2003 04:30


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.

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