fwrite() not working when appending RDP file...

[Bobby T]

Here's the problem, when I try to append an RDP file (which is written
in hex but readable in notepad) it adds funny little squares to the
file. I have tried opening the file in every mode but nothing helps.
Can anyone steer me in the right direction?

Here's my current code:

$file = "try_this.rdp";
$handle = fopen("$file","a+b");
fwrite($handle,"Hello");
fclose($handle);

I have tried opening it in binary mode (as seen above) and regular
mode. I'm not really sure when you should open something in binary
mode, I just tried it because I couldn't write to this file.

Thanks!

[TheTeapot]

The problem's with the text being written to the file. If you use a
windows server, new lines will be \r\n. If you use unix, new lines
will be \n.

I think that that's your problem.

Just do this:
$out = "I do not \n even know \n what a
RDP file is!";
$out = str_replace("\n","\r\n",$out);
$file = "test.rdp";
$handle = fopen("$file","a+b");
fwrite($handle,$out);
fclose($handle);

[TheTeapot]

The problem's with the text being written to the file. If you use a
windows server, new lines will be \r\n. If you use unix, new lines
will be \n.

I think that that's your problem.

Just do this:
$out = "I do not \n even know \n what a
RDP file is!";
$out = str_replace("\n","\r\n",$out);
$file = "test.rdp";
$handle = fopen("$file","a+b");
fwrite($handle,$out);
fclose($handle);

[Chung Leong]

What is a rdp file? Is it encoded in 16-bit Unicode? How many squares
were added?

[Bobby T]

I am not knowledgeable about file types (ASCII, Unicode, etc.). When I
try to append text to the file, two squares are added at the end of the
file (when viewing in a text editor).

I can read the file with a text editor, but if I copy the content to a
text file and name it the same (test.rdp) it is only 1KB (opposed to
the original file being 2KB) so I know there is some type of encoding
that I can't see with a text editor. I can open the file with a hex
editor and read it - does that mean it is a "hex" file? I am afraid i'm
ignorant in the matter.

At any rate, I can manually edit the file and change the ip address in
notepad and the file works fine. If i try to change it using fwrite, it
appends "squares". I'm at a loss.

Any help is GREATLY appreciated :)

Thanks!

Bobby T

[Chung Leong]

It appears the file is saved as 16-bit Unicode, as the file is twice as
large as the ASCII version. The reason why you get two at the end when
you fwrite "hello" to the file is that "he" and "ll" are interpreted by
the computer as two Unicode characters. Their value fall within the
Chinese range, which your computer probably isn't set up to display.

PHP strings are 8-bit. You need to manually pad each byte with a \0 to
expand a string to 16-bit. Try either
fwrite($handle,"H\0e\0l\0l\0o\0") or fwrite($handle,"\0H\0e\0l\0l\0o").

[Bobby T]

Hey Teapot, I tried that but still no luck. It's just adding "squares"
to the file - at least when i view from a text editor.

[Bobby T]

Chung,

It does not like the "\"s in the code. I get an unexpected T_LNUMBER
error on the page with that. I tried both of them.

Thanks,

Bobby

[Bobby T]

OK... i've learned that whatever type of file this is, if I fwrite the
following:

fwrite($handle,"f\0u\0l\0l\0 \0a\0d\0d\0r\0e\0s\0s");

it will insert "full address:"

but if i try to insert numbers it doesn't work, they show up in the
file (looking with a text editor) as squares.

IE, if i try the following...

fwrite($handle,"2\02\02");

it shows up as squares in the file when viewing with a text editor. I
need 222 to be written to the file.

[Chung Leong]

Sorry. It's safer to use "\x00" to represent 0 in a string. So 222
would be "\x002\x002\x002". The best way to do this is with
chunk_split(). Example: chunk_split("222", 1, "\x00");

[Bobby T]

Thank for all your help Chung. It looks like the problem is because of
some kind of hidden encrytpion on the file. I hate M$ more every day.