gzread

(PHP 4, PHP 5)

gzread — Leitura de arquivos-gz segura para binários

Descrição

string gzread ( resource $zp , int $length )

gzread() lê length bytes do ponteiro de arquivo gz. A leitura pára quando length (descomprimido) bytes forem lidos ou até o fim do arquivo, o que chegar primeiro.

Parâmetros

zp: O ponteiro do arquivo gz. Precisa ser válido, e apontar para um arquivo aberto com sucesso por gzopen().
length: O número de bytes a serem lidos.

Valor Retornado

The data that have been read.

Exemplos

Exemplo #1 Exemplo da gzread()


<?php
// Obtém o conteúdo de um arquivo-gz em uma string
$filename = "/usr/local/something.txt.gz";
$zd = gzopen($filename, "r");
$contents = gzread($zd, 10000);
gzclose($zd);
?>

Veja Também

gzwrite() - Escrita segura para binário em arquivo-gz
gzopen() - Abre um arquivo-gz
gzgets() - Obtém uma linha de um ponteiro de arquivo
gzgetss() - Obtém uma linha de um ponteiro de arquivo-gz e retira as tags HTML
gzfile() - Lê todo o arquivo-gz para uma matriz
gzpassthru() - Envia todos os dados restantes em um ponteiro para arquivo-gz

gzrewind

gzputs

Last updated: Fri, 24 Feb 2012

User Contributed Notes
gzread

calin_ip at yahoo dot com
10-Nov-2010 01:55


Regarding finding out the lenght of the gz file.

For some reason the seek() function didn't worked, so, I've tried finding out the last 4 bytes using string functions.

That worked pretty well. Here is the code. 

<?php

$stringu='my_beautiful_file.txt.gz';

$gzip=file_get_contents($stringu);

$rest = substr($gzip, -4); 

$GZFileSize = end(unpack("V", $rest));



$FileRead = $stringu;

$HandleRead = gzopen($FileRead, "rb");

$ContentRead = gzread($HandleRead, $GZFileSize);

gzclose($HandleRead);

?>

denis at bitrix dot ru
16-Jul-2010 06:00


Note that this functions' behavior differs from fread in case of EOF.



When you read the last chunk (mean the last bytes from file), it is EOF just after gzread, but in case of fread you need to read once more to get EOF.



Hope, I am clear :)

robinv12001 at yahoo dot co dot in
10-Jun-2009 06:21


<?php

//Extracting the content of a gzip file in php and creating a new csv file using the content

//Create a folder uploads inside current folder

$local_file    =    'test.gz';



//To Get the size of the uncompressed file

$FileRead = $local_file;

$FileOpen = fopen($FileRead, "rb");

fseek($FileOpen, -4, SEEK_END);

$buf = fread($FileOpen, 4);

$GZFileSize = end(unpack("V", $buf));

fclose($FileOpen);

//To Get the size of the zip file



$fzip_size    =    $GZFileSize;

    

$filename    =    $local_file;

$ext        =    pathinfo($filename,PATHINFO_EXTENSION);    

$file_name    =    pathinfo($filename,PATHINFO_FILENAME);        

$file_name    =    $file_name.".csv";



$zd         =     gzopen($filename, "rb");

$contents     =     gzread($zd, $fzip_size);

gzclose($zd);

$file_name    =    "uploads/".$file_name;

$fp    =    fopen($file_name, "wb");

fwrite($fp, $contents); //write contents of feed to cache file

fclose($fp);

if(file_exists($file_name))

{

    chmod($file_name,0755);

    unlink($local_file);

}

?>

robinv12001 at yahoo dot co dot in
08-Jun-2009 11:18


<?php


//Using FTP Download a gzip file on current date from a remote server


//The gzip files are extracted


function parse_rawlist( $array )


{


    $i=0;


    foreach($array as $curraw)


    {


        $struc = array();


        $current = preg_split("/[\s]+/",$curraw,9);





        $struc['perms']      =     $current[0];


        $struc['number']     =     $current[1];


        $struc['owner']     =     $current[2];


        $struc['group']      =     $current[3];


        $struc['size']         =     $current[4];


        $struc['month']      =     $current[5];


        $struc['day']        =     $current[6];


        $struc['time']      =     $current[7];


        $struc['zfile_name']      =     $current[8];


     $structure[$i]      =     $struc;


    $i++;


    }


   return $structure;





}


ini_set('memory_limit', '100M');





//Give FTP Information Here


//------------------------------------------------------------


$ftp_server     =     "example.com";


$ftp_user_name    =    "example";


$ftp_user_pass    =    "test";


//------------------------------------------------------------


//------------------------------------------------------------


$local_path     =    '/opt/lampp/htdocs/sample/test.gz';//Local Path


$server_path     =     'outgoing/folder/';//Remote Sever Path


//------------------------------------------------------------





$conn_id = ftp_connect($ftp_server,21);


if($conn_id)


{


    echo "Successfully connected";


}


  


$login_result     =     ftp_login($conn_id, $ftp_user_name, $ftp_user_pass);


ftp_chdir($conn_id, $server_path);//Change Current Working Directory


$file_list     =    ftp_rawlist($conn_id,".");


$zip_details    =    parse_rawlist($file_list);


set_time_limit(1000); 


$curr_date    =    strtotime(date("F d Y"));


for($i=0;$i<count($zip_details);$i++)


{


    $fname        =    $zip_details[$i]['zfile_name'];    


    $mod_date1    =    $zip_details[$i]['month']." ".$zip_details[$i]['day']." ".date("Y");    


    $mod_date    =    strtotime($mod_date1);//File Modified Date


    if($mod_date == $curr_date)//If modified date equals current date


    {


        $local_file    =    $fname;


        $server_file    =    $fname;


        if (ftp_get($conn_id, $local_file, $server_file, FTP_BINARY)) 


        {


        


            echo "<br/>Successfully written to $local_file\n";


        } 


        else 


        {


            echo "<br/>There was a problem\n";


        }


        if(file_exists($local_file))


        {


            $fzip_size    =    $zip_details[$i]['size'];    


            $filename    =    $local_file;


            $ext        =    pathinfo($filename,PATHINFO_EXTENSION);    


            $file_name    =    pathinfo($filename,PATHINFO_FILENAME);        


            $file_name    =    $file_name.".csv";


            $zd         =     gzopen($filename, "r");


            $contents     =     gzread($zd, $fzip_size);


            $file_name    =    "uploads/".$file_name;


            file_put_contents($file_name,addslashes($contents));


            if(file_exists($file_name))


            {


                chmod($file_name,0755);


                unlink($local_file);


            }


            gzclose($zd);


        }


    }


}


ftp_close($conn_id);


?>

utku
07-Feb-2008 11:31


I don't think it would be wise to open a whole gzip file (it _is_ compressed for a reason, and likely to be a very big file) into a single string. You would most likely hit the php memory limits. Instead, if you need to process the file, put your gzread calls in a loop, and read incrementally by a setting $length to a constant value.

zaotong at yahoo dot com
07-Mar-2007 12:06


As was shown to me in another forum there is a way to get the uncompressed size of the gz file by viewing the last 4 bytes of the gz file.



Here is a piece of code that will do this

<?php

$FileRead = 'SomeText.txt';

$FileOpen = fopen($FileRead, "rb");

        fseek($FileOpen, -4, SEEK_END);

        $buf = fread($FileOpen, 4);

        $GZFileSize = end(unpack("V", $buf));

        fclose($FileOpen);

        $HandleRead = gzopen($FileRead, "rb");

        $ContentRead = gzread($HandleRead, $GZFileSize);

?>



This will read the last 4 bytes of the gz file and use it as the file int for the gzread.



Thanks to stereofrog for helping me with this code.

methatron at hotmail dot com
26-Sep-2006 09:33


Be aware that gzread's second parameter - length reffers to the file's uncompressed size, therefore using this code:



<?php

$file_name = "/usr/local/something.txt.gz";

if($file_handle = gzopen($file_name, "r"))

{

    $contents = gzread($file_handle, filesize($file_name));

    gzclose($file_name);

}

?>



will probably truncate the content of the file as filesize checks for the file's compressed size.

So either use the actual uncompressed size, if you know it, or use an aribtrary big enough length, as gzreading will stop at the end of the file anyway.

gzrewind

gzputs

Last updated: Fri, 24 Feb 2012