Programming Forums - Strange fopen Problem

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Strange fopen Problem

I'd like to know why I'm getting the following error:

Quote:

0

Warning: fread() [function.fread]: Length parameter must be greater than 0 in C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\blah.php on line 22

with this code:

<pre>
<?php
$filename = 'foo.txt';
 
$h1 = fopen($filename, 'xb');
fwrite($h1, 'bar');
//$h2 = fopen($filename, 'rb');
//echo fread($h2, filesize($filename));
//fclose($h2);
echo file_retrieve_contents($filename);
fclose($h1);
unlink($filename);
 
function file_retrieve_contents($filename, $offset = 0, $bytes = null){
        $fileSize = filesize($filename);
        echo $fileSize;
        if(!is_int($offset)) $offset = 0;
        if(!is_int($bytes)) $bytes = $fileSize - $offset;
 
        $handle = @fopen($filename, "rb");
        fseek($handle, $offset);
        $data = fread($handle, $bytes);
        fclose($handle);
        return $data;
}
?>
</pre>

And actually getting the output:

Quote:

bar

when I do the following:

<pre>
<?php
$filename = 'foo.txt';
 
$h1 = fopen($filename, 'xb');
fwrite($h1, 'bar');
$h2 = fopen($filename, 'rb');
echo fread($h2, filesize($filename));
fclose($h2);
//echo file_retrieve_contents($filename);
fclose($h1);
unlink($filename);
 
function file_retrieve_contents($filename, $offset = 0, $bytes = null){
        $fileSize = filesize($filename);
        echo $fileSize;
        if(!is_int($offset)) $offset = 0;
        if(!is_int($bytes)) $bytes = $fileSize - $offset;
 
        $handle = @fopen($filename, "rb");
        fseek($handle, $offset);
        $data = fread($handle, $bytes);
        fclose($handle);
        return $data;
}
?>
</pre>

Anyone have any ideas?

Re: Strange fopen Problem

With the second code you tell it to do a write to the file

fwrite($h1, 'bar');

which will then give it the string 'bar'.
If you are trying to get it to add more text in to the file try:

$h1=fopen($filename, 'a');

Re: Strange fopen Problem

I'm not attempting to add more. I'm attempting to read that which has already been written.

Re: Strange fopen Problem

then your code should be:

<pre>
<?php
 
$filename = 'foo.txt';
$h2 = fopen($filename, 'rb');
echo fread($h2, filesize($filename));
fclose($h2);
//echo file_retrieve_contents($filename);
fclose($h1);
unlink($filename);
 
function file_retrieve_contents($filename, $offset = 0, $bytes = null){
$fileSize = filesize($filename);
echo $fileSize;
if(!is_int($offset)) $offset = 0;
if(!is_int($bytes)) $bytes = $fileSize - $offset;
$handle = @fopen($filename, "rb");
fseek($handle, $offset);
$data = fread($handle, $bytes);
fclose($handle);
return $data;
}
 
?></pre>

Re: Strange fopen Problem

In the first one your are getting the file size before you open the file again, in the second you open the file for reading before you get the file size. I suspect there that the write isn't being flushed to disk until a different IO is performed, so the file's size on disk doesn't match what you think it does.