Linux: Command Belongs To Which RPM

If you want to install a Command and not sure which package it belongs to. Here are the steps:

[root@vm1 /]# nslookup vm1
-bash: nslookup: command not found

I am trying to use "nslookup" but it does not exist on the server.

But I have CD mounted with repository configured.

Now find out which RPM has the command.

root@vm1 /]# yum whatprMatched from:

Filename    : /usr/share/zsh/4.3.10/functions/nslookup

32:bind-utils-9.8.2-0.7.rc1.el6.x86_64 : Utilities for querying DNS name servers

Repo        : cluster

Matched from:

Filename    : /usr/bin/nslookup

32:bind-utils-9.8.2-0.7.rc1.el6.x86_64 : Utilities for querying DNS name servers

Repo        : server

Matched from:

Filename    : /usr/bin/nslookup

zsh-4.3.10-5.el6.x86_64 : A powerful interactive shell

Repo        : server

Matched from:

Filename    : /usr/share/zsh/4.3.10/functions/nslookup

So, You can install any of the above RPM to get the Command. :)

Linux: Show the number of CPU cores and sockets on your system

dmidecode -t 4 |grep Thread # number or cpu listed as well by cat /proc/cpuinfo

dmidecode -t 4 |grep CPU # number of physical CPU

Appending groups to a user

For example, if testuser is a member of  group1 and group2, and you need to add the user to group3, the command would be:

usermod -G group1,group2,group3 testuser

If you mistakenly ran:

usermod -G group3 testuser

Then testuser would be removed from group1 and group2 and only be a member of group3.