Ufdjrw

I want to create some virtual serial ports for some experiments. On Windows I use com0com null-modem emulator, as I have explained here. On macOS I have installed socat using HomeBrew:

brew install socat

and it seems to be installed just fine. Now using the command from here:

sudo socat PTY,link=/dev/ttyS98 PTY,link=/dev/ttyS99

leads to the error message:

E symlink("/dev/ttys001", "/dev/ttyS98"): Operation not permitted

The other one-liner from here:

sudo socat -d -d pty,raw,echo=0 pty,raw,echo=0

seems to create the two virtual ports:

N PTY is /dev/ttys001

N PTY is /dev/ttys002

N starting data transfer loop with FDs [5,5] and [7,7]

but when I try to actually write/read between the two:

sudo echo "test signal" > /dev/ttys001

and

sudo tail -f /dev/ttys002

or

sudo cat </dev/ttys002

I get the:

Permission denied

error messages. Moreover, when I try to list the serial ports using the command from here:

ls /dev/tty,cu.*

I don't see those above ports. I would appreciate if you could help me know what is the problem and how I can solve this.

P.S.1. My bash --version is:

GNU bash, version 5.0.2(1)-release (x86_64-apple-darwin18.2.0)

P.S.2. It is really sad that we still see some users here on SO through down-votes without explaining their motives. How am I expected to improve if I'm not being told what is wrong with my post?

P.S.3. I'm running the commands as sudo so the point mentioned in this comment shouldn't be the issue.

P.S.4. Running the command from here:

sudo socat -d -d pty,raw,echo=0,link=/tmp/ttyV0 pty,raw,echo=0,link=/tmp/ttyV1

Is just like the second case above.

P.S.5. I'm going to try tty0tty as suggested here.

P.S.6. I tried the commands on Linux too with the similar issues, except the first command does not lead to the Operation not permitted error.