coreutils <https://www.gnu.org/software/coreutils/manual/html_node/mknod-invocation.html#mknod-invocation >
Create character, block or FIFO (named pipe) files.
mkfifo can also create FIFOs and is POSIX.
Create a char file with major number 1 and minor number 9:
sudo mknod -m 666 /tmp/myurandom1 c 1 9
sudo mknod -m 666 /tmp/myurandom2 c 1 9
Since those are the specifications for urandom as shown by stat /dev/urandom, we have created a new entry point for urandom:
head -c10 /tmp/myurandom1 | od
head -c10 /dev/myurandom2 | od