gzread

(PHP 4, PHP 5)

gzread — バイナリ対応のgzファイル読み込み

説明

string gzread ( resource $zp , int $length )

gzread() は、最大 length バイトのデータを zp が指す gz ファイルポインタから読み込みます。(伸長された) length バイトのデータが読み込まれたか、 EOF に達したとき、読み込みは終了します。

パラメータ

zp: gz ファイルポインタを指定します。これは有効なファイルポインタであり、かつ、gzopen() によりオープンできたファイルを指している必要があります。
length: 読み込むバイト数を指定します。

返り値

読み込まれたデータ

例

例1 gzread() の例


<?php
// gz ファイルの内容を文字列に読み込む
$filename = "/usr/local/something.txt.gz";
$zd = gzopen($filename, "r");
$contents = gzread($zd, 10000);
gzclose($zd);
?>

参考

gzwrite() - バイナリセーフな gz ファイル書き込み
gzopen() - gz ファイルを開く
gzgets() - ファイルポインタから 1 行を得る
gzgetss() - gzファイルへのポインタから1行を得て、HTMLタグを取り除く
gzfile() - gzファイル全体を配列に読み込む
gzpassthru() - gzファイルへのポインタから残りのデータ全部を出力する

gzrewind

gzputs

[edit] Last updated: Fri, 10 Feb 2012

add a note User Contributed Notes gzread

calin_ip at yahoo dot com 10-Nov-2010 12:55


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 11-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 09-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 08-Feb-2008 10:31


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 08-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 27-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.

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