PHP overwriting file issues

Question

I have a problem while overwriting a file. I tried everthing but SOMETIMES (maybe for a matter of time) nothings seems to work as it should. Here's the code:

include_once "changevar.php";
changevar("O",$seguimedia,$filename,0);
changevar("o",$offerta,$filename,0);

$seguimedia, $filename and $offerta are correctly set.

changevar.php:

function changevar($varname,$newval,$filename,$type)
{
    while(!$fp=fopen($filename,"c+"))
    {
        usleep(100000);
    }
    while(!flock($fp,LOCK_EX))
    {
        usleep(100000);
    }
    while(!include($filename))
    {
        usleep(100000);
    }
    ftruncate($fp,0);
    rewind($fp);
    $$varname=$newval;
    if($type==0)
    {
        foreach(array("u","p","t","d") as $v){$$v=str_replace("\\","\\\\",$$v);}
        $text="<?\$o=$o;\$u=\"$u\";\$c=$c;\$m=$m;\$p=\"$p\";\$C=$C;\$id=\"$id\";\$t=\"$t\";\$d=\"$d\";\$O=$O;?>";
    }
    else
    {
        $text="<?\$impressions=$impressions;\$clickunici=$clickunici;\$clicknulli=$clicknulli;\$creditiguadagnati=$creditiguadagnati;\$creditiacquistati=$creditiacquistati;\$creditiutilizzati=$creditiutilizzati;?>";
    }
    fwrite($fp,$text);
    flock($fp,LOCK_UN);
    fclose($fp);
}

In this case the function changevar() has to change two variables ($o and $O) in the file $filename but often it fails and nothing changes. How can I fix this?

Answer 1

Make sure you have write permissions and correct user set to change the file content. You can do that with chown and chmod in linux systems. Not sure if its an issue on windows boxes.

see http://php.net/manual/en/function.chmod.php and http://www.php.net/manual/en/function.chown.php