gzread

(PHP 4, PHP 5)

gzread — .gz로부터 바이트값을 읽어들인다

Description

string gzread ( int $zp , int $length )

gzread()은 zp 로부터 참조된 지정된 .gz 파일로부터 length 만큼의 byte값을 읽어들인다. length (압축되지 않은)만큼의 byte를 읽거나 EOF에 다다르면 읽기를 멈춘다. (처음으로 돌아가는것 포함)


// get contents of a gz-file into a string
$filename = "/usr/local/something.txt.gz";
$zd = gzopen ($filename, "r");
$contents = gzread ($zd, 10000);
gzclose ($zd);

참고 gzwrite(), gzopen(), gzgets(), gzgetss(), gzfile(), gzpassthru().

gzrewind

gzputs

Last updated: Sun, 25 Nov 2007

add a note User Contributed Notes
gzread

utku
08-Feb-2008 01:31


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 03:06


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 12:33


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.

add a note

gzrewind

gzputs

Last updated: Sun, 25 Nov 2007