Linux Ask! is a Q & A web site specific for Linux related questions. Questions are collected, answered and audited by experienced Linux users.
Show the system ARP cache
Answer:
Show the current content of the current ARP table
# arp
Address HWtype HWaddress Flags Mask Iface
192.168.1.5 ether 00:00:0c:07:ac:0c C eth0
Display current system hardware architecture
Answer:
arch can display the current system hardware architecture name (same as uname -m)
# arch
x86_64
How to broadcast text message to all users
Answer:
To broadcast message on the terminals of all currently logged in users, use the wall command
# echo "Hello" | wall
Execute command as another user
Answer:
If you want to run command as another user, you can use the following method:
# sudo su mark -c 'whoami'
mark
Assume currently logged in as user other than mark.
Spying on the physical console
Answer:
When you connect to your remote Linux server using SSH, sometimes you would like to see the message that appear in the console, you can view using the following method:
# tail -f /dev/vcs1
Where vcs1 means the virtual terminal 1, possible options are 1, 2, 3, 4 etc.
The method will save you many time from always need to visit the physical server.
