'apropos subject' – List manual pages for subject

'man -k keyword' – Display man pages containing keyword

'man command' – Show the manual for command

'man -t man | ps2pdf' - > man.pdf – Make a pdf of a manual page

'which command' – Show full path name of command

'time command' – See how long a command takes

'whereis app' – Show possible locations of app

'which app' – Show which app will be run by default; it shows the full path

'grep pattern files' – Search for pattern in files

'grep -r pattern dir' – Search recursively for pattern in dir

'command | grep pattern' – Search for pattern in the output of command

'locate file' – Find all instances of file

'find / -name filename' – Starting with the root directory, look for the file called filename

'find / -name ”*filename*”' – Starting with the root directory, look for the file containing the string filename

'locate filename' – Find a file called filename using the locate command; this assumes you have already used the command updatedb (see next)

'updatedb' – Create or update the database of files on all file systems attached to the Linux root directory

'which filename' – Show the subdirectory containing the executable file called filename

'grep TextStringToFind /dir' – Starting with the directory called dir, look for and list all files containing TextStringToFind

'chmod octal file' – Change the permissions of file to octal, which can be found separately for user, group, and world by adding: 4 – read ®, 2 – write (w), 1 – execute (x)

Examples:

'chmod 777' – read, write, execute for all

'chmod 755' – rwx for owner, rx for group and world

For more options, see man chmod.

'ls' – Directory listing

'ls -l' – List files in current directory using long format

'ls -laC' – List all files in current directory in long format and display in columns

'ls -F' – List files in current directory and indicate the file type

'ls -al' – Formatted listing with hidden files

'cd dir' – Change directory to dir

'cd' – Change to home

'mkdir dir' – Create a directory dir

'pwd' – Show current directory

'rm name' – Remove a file or directory called name

'rm -r dir' – Delete directory dir

'rm -f file' – Force remove file

'rm -rf dir' – Force remove an entire directory dir and all it’s included files and subdirectories (use with extreme caution)

'cp file1 file2' – Copy file1 to file2 ' cp -r dir1 dir2' – Copy dir1 to dir2; create dir2 if it doesn't exist

'cp file /home/dirname' – Copy the filename called file to the /home/dirname directory

'mv file /home/dirname' – Move the file called filename to the /home/dirname directory

'mv file1 file2' – Rename or move file1 to file2; if file2 is an existing directory, moves file1 into directory file2

'ln -s file link' – Create symbolic link link to file

'touch file' – Create or update file

'cat > file' – Places standard input into file

'cat file' – Display the file called file

'more file' – Display the file called file one page at a time, proceed to next page using the spacebar

'head file' – Output the first 10 lines of file

'head -20 file' – Display the first 20 lines of the file called file

'tail file' – Output the last 10 lines of file

'tail -20 file' – Display the last 20 lines of the file called file

'tail -f file' – Output the contents of file as it grows, starting with the last 10 lines

'tar cf file.tar files' – Create a tar named file.tar containing files

'tar xf file.tar' – Extract the files from file.tar

'tar czf file.tar.gz files' – Create a tar with Gzip compression

'tar xzf file.tar.gz' – Extract a tar using Gzip

'tar cjf file.tar.bz2' – Create a tar with Bzip2 compression

'tar xjf file.tar.bz2' – Extract a tar using Bzip2

'gzip file' – Compresses file and renames it to file.gz

'gzip -d file.gz' – Decompresses file.gz back to file

'/etc/rc.d/init.d/lpd start' – Start the print daemon

'/etc/rc.d/init.d/lpd stop' – Stop the print daemon

'/etc/rc.d/init.d/lpd status' – Display status of the print daemon

'lpq' – Display jobs in print queue

'lprm' – Remove jobs from queue

'lpr' – Print a file

'lpc' – Printer control tool

'man subject | lpr' – Print the manual page called subject as plain text

'man -t subject | lpr' – Print the manual page called subject as Postscript output

'printtool' – Start X printer setup interface

'ifconfig' – List IP addresses for all devices on the local machine

'iwconfig' – Used to set the parameters of the network interface which are specific to the wireless operation (for example: the frequency)

'iwlist' – used to display some additional information from a wireless network interface that is not displayed by iwconfig

'ping host' – Ping host and output results

'whois domain' – Get whois information for domain

'dig domain' – Get DNS information for domain

'dig -x host' – Reverse lookup host

'wget file' – Download file

'wget -c file' – Continue a stopped download

'ssh user@host' – Connect to host as user

'ssh -p port user@host' – Connect to host on port port as user

'ssh-copy-id user@hos't – Add your key to host for user to enable a keyed or passwordless login

'adduser accountname' – Create a new user call accountname

'passwd accountname' – Give accountname a new password

'su' – Log in as superuser from current login

'exit' – Stop being superuser and revert to normal user

'ps' – Display your currently active processes

'top' – Display all running processes

'kill pid' – Kill process id pid

'killall proc' – Kill all processes named proc (use with extreme caution)

'bg' – Lists stopped or background jobs; resume a stopped job in the background

'fg' – Brings the most recent job to foreground 'fg n' – Brings job n to the foreground

'./configure'

'make'

'make install'

'dpkg -i pkg.deb' – install a DEB package (Debian / Ubuntu / Linux Mint)

'rpm -Uvh pkg.rpm' – install a RPM package (Red Hat / Fedora)

'shutdown -h now' – Shutdown the system now and do not reboot

'halt' – Stop all processes - same as above

'shutdown -r 5' – Shutdown the system in 5 minutes and reboot

'shutdown -r now' – Shutdown the system now and reboot

'reboot' – Stop all processes and then reboot - same as above

'startx' – Start the X system