what does this do?

[thefollower]

Some one showed me a bit of script then failed to tell me what it does lol .

 

So was hoping some one could explain what this does:

 

$response is from a $_POST and relates to a message..

 

$Response = str_replace(array("\r\n", "\r", "\n"), ' ', $Response);

 

Hope you can explain it

[tinker]

http://uk3.php.net/manual/en/function.str-replace.php, always use the manual as first stop when learning, it's unbelievably informative (look for the search bar, then the 'See Also' section before the comments, then the left menu)

[thefollower]

I had already read that and it says :

 

// Processes \r\n's first so they aren't converted twice.

 

 

And then well.. why would it convert those 2 letters twice anyway i dont understand why it would need to convert anything ? Is there a dangerous security flaw with users typing \r\n's into a string which is why he replaces them ?

[revraz]

No, they are just line feeds.

[Barand]

On a Mac system a newline is "\r" (carriage return)

On a Nix system a newline is "\n"  (linefeed)

 

Windows however never evolved from the days of the old mechanical teletype which required the carriage to be returned back to the left hand edge and the paper fed forward, so it requires "\r\n" (carriage_return + linefeed)

 

So the code replaces all flavours with a single space,