ping

Checks an IP address for network connectivity

ifconfig

Used to view network and configuration information like IP and MAC addresses.

mount

Make particular file system accessible at a certain point in the directory tree

diff

Analyzes two files and prints the lines that are different

comm

Compare two sorted files line by line.

scp

Copy files securely over SSH

shred

Deletes files

sort

Sorts text line by line. Many kinds of sorts.

source

Evaluates file as a list of commands executed in the current context

sftp

Utilize secure file transfer protocol on a server.

ssh

Utilize secure shell network protocol to gain secure access to a server.

wget

A command line utility used to download files from servers on the internet.

history

Lists up to the 1000 most recent commands executed in the terminal.

alias

Assign a string to be recognized as a different one. Often used with a command.

which

Locates pathnames of the files that would be run by the shell if given a command.

who

Shows which user(s) are currently logged in on the machine

chmod

Modify the read, write, and execute priveleges of files for users and groups.

chown

Change ownership information of files.

grep

Search a file for keywords and return the line in which it appears in the file.

traceroute

Trace the path of a packet from its genesis to its final destination.