Sed from Serial Stream

Question

I'm using a Raspberry Pi with a Serial device connected over USB (/dev/ttyACM0). I can write the data to the console with cat /dev/ttyACM0.

But when I try to replace the $ signs in the output with a newline cat /dev/ttyACM0 | sed 's/\$/\n/g' i get no output.

When I write the output of cat to a file and then replace the $ signs with cat file | sed 's/\$/\n/g' it works.

Is there any option for sed that it will work?

did you try `cat /dev/ttyACM0 | sed "s/\$/\n/g"` (or `sed --unbuffered "s/\$/\n/g" /dev/ttyACM0`) — NeronLeVelu, Jan 07 '15 at 08:45

score 2 · Answer 1 · answered Jan 06 '15 at 15:24

2

Try sed's option --unbuffered.

answered Jan 06 '15 at 15:24

Cyrus

score 2 · Accepted Answer · answered Jan 06 '15 at 15:51

2

Try this I'm pretty sure that it will work,

cat /dev/ttyACM0 | tr '$' '\n'

answered Jan 06 '15 at 15:51

Arnab Nandy

1

Right, `sed` waits to receive a full line of text, but `tr` will make replacements char by char. – Markku K. Jan 06 '15 at 16:00

2 Answers2