Can we use fifos for transfering data from device driver to an user ap

[tanniru]

Can we use fifos for transfering data from device driver to an user application?

[ramin.honary]

Yes you can use FIFO's for that purpose. However it is not necessary.

You can just read the device driver file directly. For example:

hexdump /dev/random

Using a FIFO in between the application and the device file is just adding an extra complication.

If you are writing a script to access data from a driver like "/dev/audio", you may need set the group identity of the script file using "chgrp audio script.file", and then "chmod" the "setgid" permissions bit of the script file using "chmod g+s script.file. If you do this, executing the script will allow you to access the device file as a member of that group. Be careful of security, you may not want all users of that group to be able to use that script -- it depends on the purpose of your script.

If you want to use a program like "tee" to read data from a device and copy it to more than one FIFO so many applications can receive the same data, just keep in mind that "tee" needs to buffer the data it sends, and it will not read another buffer-full of data from your device until every FIFO has read its data from "tee", and this means the data access to all programs will be as slow as the slowest program reading it.