On Thu, Jul 06, 2006 at 10:41:55AM +0100, Jenny Hopkins wrote:

I'm trying to echo a command to a serial port that happens to require a "!". In order to send the command I need to escape the ! with a backslash. However, I'm finding that at the other end, the backslash stays there rather than being stripped off, so the received command is also escaped and therefore doesn't work.

Emulated on a terminal: I send jenny@phaedrus:~$ echo "!tts MALE" > /dev/ttyp2 and receive !tts MALE

But I need to receive !tts MALE

Any hints on how to acheive this?

Try single quotes: echo '!tts MALE' > /dev/ttyp2

J.

On Thu, Jul 06, 2006 at 10:41:55AM +0100, Jenny Hopkins wrote:

Hullo there,

I'm trying to echo a command to a serial port that happens to require a "!". In order to send the command I need to escape the ! with a backslash. However, I'm finding that at the other end, the backslash stays there rather than being stripped off, so the received command is also escaped and therefore doesn't work.

Emulated on a terminal: I send jenny@phaedrus:~$ echo "!tts MALE" > /dev/ttyp2 and receive !tts MALE

But I need to receive !tts MALE

That is because you quote the entire string. Quoting removes the special meaning of all characters (with the exception of $ in the case of double quoting), so the backslash in quotes represents a backslash character and is not interpreted as part of an escape sequence.

So, either

!tts MALE

or

"!tts MALE"

will work as expected, but not both.

Best regards, Jan