transferring \n to linux from perl via serial port

digital_newbie has asked for the wisdom of the Perl Monks concerning the following question:

Hi,

I am trying to control an OMAP with Linux, from a Windows laptop running Perl via serial port. I could open serial port (COM1) and send commands, but not able to execute them by sending the enter key. I tried \n but it only moving the cursor to the next line, and not imitating enter key. Code is below. Any suggestions? Please help!!

open( PORT, "+>COM1") or die "Cant open COM1 - $!";

$msg="ls\n";

print PORT $msg;
[download]

The output comes as

.#ls
|
[download]

but doesn't execute..

Thanks
Joseph
https://nurosoft.id/
https://flits.id/

Code tags and various other formatting corrected by Grandfather

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Re: transferring \n to linux from perl via serial port by stevieb (Canon) on Nov 28, 2020 at 16:30 UTC
Just a guess, and I have no configuration to test with currently, but try sending `\r\n` and see if that helps. A lot of software requires a carriage return (`\r`) and a newline (`\n`) to be sent in.	[reply] [d/l] [select]
Re^2: transferring \n to linux from perl via serial port by haukex (Archbishop) on Nov 29, 2020 at 12:45 UTC
Just a guess, and I have no configuration to test with currently, but try sending `\r\n` and see if that helps. Sorry, I think that's unlikely to help, as on Windows, that will cause `\r\r\n` to be transmitted - see my post.	[reply] [d/l] [select]
Re: transferring \n to linux from perl via serial port by haukex (Archbishop) on Nov 29, 2020 at 11:36 UTC
from a Windows laptop running Perl via serial port Because this is Windows, the default `:crlf` PerlIO layer is converting your `"ls\n"` into `"ls\x0D\x0A"` (i.e., CRLF), which might be the source of your issues. Try `binmode PORT;` after your `open` to see if that helps. If it doesn't help, you'll have to check the specifications of the serial protocol for what is expected. By the way, Use strict and warnings, and see also "open" Best Practices in regards to using three-agrument open and lexical filehandles.	[reply] [d/l] [select]
Re: transferring \n to linux from perl via serial port by LanX (Saint) on Nov 28, 2020 at 20:18 UTC
on a side note, you can set `$\` to whatever newline-code is needed. it'll be appended to every print then. ~~Please edit your post and change `<.code>` to `</code>`~~ (considered) Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery}	[reply] [d/l] [select]