Different ways to find the linux kernel version

Here are two ways to find out the currently running kernel version of linux

1. Using uname to find the linux kernel version

$ uname -r 3.2.1

2. Using sysctl to find the linux kernel version

$ sysctl kernel.osrelease kernel.osrelease = 3.2.1

3. Using proc entry to find the linux kernel version

$ cat cat /proc/sys/kernel/osrelease 3.2.1