Getting Hostname in Bash in Linux

 In Bash, you can get the hostname of the node in at least 2 ways:

• Use the variable $HOSTNAME.
• Get the hostname by command hostname.
• Get the content of /proc/sys/kernel/hostname   

Get the content of /proc/sys/kernel/hostname

$ echo $HOSTNAME
host01
$ hs=`hostname`
$ echo $hs
host01
$ cat /proc/sys/kernel/hostname
host01