I need an expert to check this code

[DeNasio]

Hello,

I have some very important files that I have to update regularly. I used to do this in PERL but now I want to switch to PHP. I've created the following piece of code to open, lock, read, write and then close a file all at once. The code is as follows:

$filename = "veryimportantfile.irs";
$file = fopen($filename, "r+");
flock($file,2); 
$text = fread ($file, filesize ($filename));
.....edit the input here.........
rewind($file);
ftruncate($file,0); 
fwrite($file, $text);
fclose($file); 

I've tested this code and it seems to be working fine. But I want someone else to take a look at it before I really start using it. The files that I want to update are very important so I can't afford to have a script that doesn't work properly or that will corrupt the files.

Please take a look and tell me what you think.

P.S. I don't want to read the file and then open it for writing, it MUST be done all at once. Can't explain any further but this is a must.

[New Oddity]

Secrecy is the fuel for sceptical ppl...