I have a serial device attached to my PC's usb port, and get /dev/ttyUSB0. Then I run minicom on it, and run strace -p <minicom pid> to monitor minicom's activity.

I found that, when I send text to /dev/ttyUSB0, every text message was appended an \r character, i.e. 0x0D.

I have done the same work using kermit and found the same result.

So my first doubt is: why these tools append the \r character?

Also, I know that in Unix ecosystem, \n is used for new line character, why these serial tools append \r but not \n? This is my second doubt.

I have googled "minicom send carriage return", "minicom add carriage return", "minicom carriage return", but find no result, and it seems that the content of minicom in internet is sometimes rare...

At last, please allow me to issue my last question: if minicom still an active project, I find it not update from Dec, 2013 from its mainpage, but kermit project is updated more recently.

1 Answer 1


The main use of minicom during its heyday was for talking to modems which understood the Hayes command set (AT commands). AT commands are terminated by carriage return. It was convenient to be able to type ATDT5550123 Enter and have the correct command terminator sent to the modem.

  • Thanks very much! So does this apply to Kermit, too?
    – cifer
    Nov 13, 2014 at 7:24

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.