awk # pattern scanning and processing language
basename # strip directory and suffix from filenames
bg # resumes suspended jobs without bringing them to the foreground
cat # print files
cd # change the shell working directory.
chmod # change file mode
chown # change file owner and group
crontab # maintain crontab files
curl # transfer a URL
cut # remove sections from each line of files
date # display or set date and time
dig # DNS lookup utility
df # report file system disk space usage
diff # compare files line by line
du # estimate file space usage
echo # display a line of text
find # search for files in a directory hierarchy
fg # resumes suspended jobs and bring them to the foreground
grep # print lines matching a pattern
kill # send a signal to a process
less # read file with pagination
ln # create links
ls # list directory contents
lsb_release # print distribution-specific information
lsof # list open files
mkdir # create
mv # move files
nc # arbitrary TCP and UDP connections and listens
netstat # print network connections, routing tables, interface statistics...
nice # execute a utility with an altered scheduling priority
nproc # print the number of processing units available
passwd # change user password
pgrep # look up processes based on name and other attributes
pkill # send signal to processes based on name and other attributes
printenv # print all or part of environment
pwd # print name of current/working directory
top # display Linux processes
tr # translate or delete characters
ps # report a snapshot of the current processes
rm # remove files or directories
rmdir # remove directories
rsync # remote file copy
scp # secure copy (remote file copy program)
sed # stream editor for filtering and transforming text
sleep # suspend execution for an interval of time
sort # sort lines of text file
ssh # OpenSSH SSH client (remote login program)
ssh-keygen # SSH key generation, management and conversion
su # substitute user identity
sudo # execute a command as another user
tail # output the last part of files
tar # manipulate archives files
tr # translate or delete characters
uname # Print operating system name
uniq # report or omit repeated lines
uptime # show how long system has been running
w # Show who is logged on and what they are doing
whereis # locate the binary, source, and manual page files for a command
which # locate a command
wc # print newline, word, and byte counts for each file
xargs # build and execute command lines from standard input
| # redirect standard output to another command
> # redirect standard output
< # redirect standard input
& # send process to background