problem with chr

sois

I am trying to write a series of hex numbers to a file as ascii bits. Everything works fine until i try to convert 0A (hex number) to decimal then to ascii with chr().

It for some reason inserts 0D for no reason and it only does it on this particular instance.

Here is part of my code, this has been killing my head. Yes, the two hex values are supposed to switch sides. For example, the first value is 34506, hex value 86CA. Its supposed to write the ascii for CA 86 to the file.

Thanks.

$hexy = 34506;
while ($noteam < 30)
	{
	$hexy = $hexy + 8;
	$bit2 = substr(dechex($hexy), 0, 2); 
	$bit1 = substr(dechex($hexy), 2, 2); 
	$lineup .= chr(hexdec($bit1));
	$lineup .= chr(hexdec($bit2));
	$noteam++;

}

fwrite ($handle, $lineup);

bad76

Hi,
the problem is that: 0x0A is the value of return.
In MS-DOS like filesystem this code is doubled in (0x0A,0x0D).

If oyu can't use a UNIX server, the only solution I can think is to put a length. When there is the length fwrite() use a different routine...

fwrite ($handle, $lineup, strlen($lineup));

And try also with a "wb" as open mode (b is for binary...) instead of "w".

Good luck...

sois

Thanks! This is excellent to know. Any other ascii codes that have problems like this?

bad76

The 0, I think.
Whitout binary mode you can have a lot of problem to read the 0.

However all char under 0x20 hex (ascii for the space...) are reserved to the system. (0x8 = backspace, 0x9 = tab, etc..).

But 0x0A and 0x0D are an old history; derives from typewriter:
is an "emulator" for the lever to put back the carrier to the left (0x0A, the CARRIER RETURN, CR) and turn the cylinder to the next line (0x0D, the LINE FEED, LF)...

I think the MS-DOS is the only using both (Unix, for example, don't use this two, but only LF).

You can try in a dos shell with typing 10 on num-keypad and 13 while pressing ALT.

see you