Which tty is serial port

The OP already knew what tty stood for. Ken Gober Ken Gober The screen buffer size is configurable. I have it set at lines.

That should be enough for everybody. Another part of the puzzle that modern users may be missing is that the fact that device names are allocated by the system is a modern innovation. Historically, installing a device would have involved a manual decision on what name to give it and then setting up a device node on the file system to point to its driver. Therefore, using a name that reflects usage rather than device type is simply a matter of picking an appropriate name while installing the device.

Today we use aliases to reflect this, as you point out, but that's only necessary because we use device type based names now. Even devfs was introduced in Linux with version 2. I actually remember the "wow" feeling when devfs and udev were introduced, respectively. Also, udev is essentially userland software managing it for the "system" as in the kernel.

I may be totally mis-remembering but on at least one system, wasn't the S indicative of using modem-control lines? Show 1 more comment. Sign up or log in Sign up using Google. Sign up using Facebook.

Sign up using Email and Password. Post as a guest Name. Its code does exactly what I had in mind:. However , serial devices that are provided through Bluetooth cause the system driver to try to connect to the Bluetooth device, which takes a while before it'll return with a timeout error.

This is caused by just opening the device. And I can imagine that similar things can happen on Linux as well - ideally, I should not need to open the device to figure out its type. I wonder if there's also a way to invoke ioctl functions without an open, or open a device in a way that it does not cause connections to be made?

My system 2. This is a USB-Serial adapter, as you can see. Hope this helps :. I'm doing something like the following code. It works for USB-devices and also the stupid serialdevuices that we all have 30 of - but only a couple of them realy works. Basically I use concept from previous answers. Then the devices actually containing a devices in then accepted as valid serial-port depending on the target of the driver-symlink fx.

I have no serial device here to test it, but if you have python and dbus you can try it yourself. GetAllDevicesWithProperties to see if the capability name "serial" that I just guessed has a different name.

Note that on other unix platforms, the serial ports are not named ttyS? Assuming a pattern in the serial devices names is wrong. Here is my piece of code based on the reply of mk2.

Maybe this helps someone:. The serial communication manager library has many API and features targeted for the task you want. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Note that if "echo" is set per stty then a jumper creates an infinite loop. Bytes that pass thru the jumper go into the port and come right back out of the other pin back to the jumper.

Then they go back in and out again and again. Whatever you send to the port repeats itself forever until you interrupt it by removing the jumper, etc. This may be a good way to test it as the repeating test messages halt when the jumper is removed. As a jumper you could use a mini or micro jumper cable sold in some electronic parts stores with mini alligator clips. A small scrap of paper may be used to prevent the mini clips from making electrical contact where it shouldn't.

Metal paper clips can sometimes be bent to use as jumpers. Whatever you use as a jumper take care not to bend or excessively scratch the pins. See Serial Electrical Test Equipment for more info. Another way to try to identify a serial port is to connect some physical serial device to it and see if it works. But a problem here is that it might not work because it's not configured right. A serial mouse might get detected at boot-time if connected.

You may put a device, such as a serial mouse use baud , on a port and then use minicom or picocom to communicate with that port. Then by clicking on the mouse, or otherwise sending characters with the device, see if they get displayed. Is there a command that tells me the port the device is connected to directly? Only way to do this until now was to disconect and reconnect and using the command:. I'm not quite certain what you're asking.

So this answer is about finding the dev path for each device. Typically only real USB devices will have this attribute, and so we can filter with it. If we don't, you'll see a lot of things in the list that aren't physical devices. So we search for directories matching this criteria.

This filters out things which aren't actual devices. The exit exits the subshell, which flows to the next iteration of the loop. The udevadm info -q property --export command lists all the device properties in a format that can be parsed by the shell into variables. So we simply call eval on this.

This is also the reason why we wrap the code in the parenthesis, so that we use a subshell, and the variables get wiped on each loop. Assuming that you know what the device you plugged in is, in And the first line lists bus and port, as well as the device number that lsusb gives.

You can get all that info from sysfs, no need for udevadm or other programs which are not available on embedded linux systems.