cd Change directory, used to navigating directory structures via the command line.
example: me13m1001@Edison20]$ cd /etc/X11 (this command changes the current working directory (cwd) to /etc/X11)
cp Copy files, used for copying files to and from different directories.
example: me13m1001@Edison20]$ cp ~/foo.txt /mnt/storage (this command copies the file foo.txt from /home/user1/foo.txt to /mnt/storage/foo.txt)
head Ouput the first part of files to the terminal
example: me13m1001@Edison20]$ head mytextfile.txt (this command outputs the the first N lines of the file mytextfile.txt. by defauilt this is 10 lines.)
ifconfig Ifconfig is used to view the IP address of the system.
example: me13m1001@Edison20]$ ifconfig (this command issued by itself will print all currently configured network interfaces.)
kill Terminate a currently running or rogue process.
example: me13m1001@Edison20]$ kill -9 27068 (this command terminates a process with a process id of 27058 found by using the command ps aux.)
less Less is a program similar to more, view the contents of a file in readonly mode with page by page.
example: me13m1001@Edison20]$ less mytextfile.txt (this command displays your mytextfile.txt)
ls Lists files, directories and their respective permissions (depending on the switches and options used.)
example: me13m1001@Edison20]$ ls -als (this command lists all of the files and subdirectories in the current working directory (cwd). You can use ls for simple listing, ll for long listing )
man Man formats and displays the on-line manual pages.
example: me13m1001@Edison20]$ man ls (this command will display the ls command man page and a verbose list of options and usage.)
mv Move files from one directory to another. (similar to cut) this option deletes the file from the original location and moves it to another, it is also used to rename files.)
example: me13m1001@Edison20]$ mv foo.rpm foo2.rpm (this command renames foo.rpm to foo2.rpm within the same directory.)
nano Nano is a small, free and friendly editor in terminal.
example: me13m1001@Edison20]$ nano mytextfile.txt (this command displays the text file mytextfile.txt in a terminal window and presents it for editing or reading.)
passwd Passwd is used to change user’s Password. Password should not be a dictionary word and need to have atleast one number ( 0-9) and punctuation characters like @ ) ( – +
example: me13m1001@Edison20]$ passwd (this command prompts the issuer to provide a new password for the given user and then updates the password database accordingly replacing the previous password with the new one.)
ps Prints a list of currently running processes, their respective owners and process id’s.
example: me13m1001@Edison20]$ ps aux (this command displays the currently running processes among other important data about the respective processes.)
pwd Print the name of the working directory.
example: me13m1001@Edison20]$ pwd (this command prints the current path/working directory in your shell, such as: /home/user1/foo)
quota Displays a list of users’ disk usage and limits. If you are getting Disk quota error You can user this command to see your disk usage and limits
example: me13m1001@Edison20]$ quota (this command displays the requested users disk quota usage and limits.)
rm Remove files and/or directories.
example: me13m1001@Edison20]$ rm mytextfile.txt (this command removes the directory mytextfile.txt)
ssh Starts the secure shell connection with a system running the sshd (secure shell daemon).
example: me13m1001@Edison20]$ ssh -l me13p1001 s3 (this command opens a remote terminal of me13p1001 user on s3 system. )
tail Output the last part of a file.
example: me13m1001@Edison20]$ tail -n 5 vhosts.conf (this command outputs the last 5 lines of the file vhosts.conf to the terminal.)
tar The tar command compresses or uncompresses tar or tar.gz archived files and directory structures.
example: me13m1001@Edison20]$ tar -xvfz foo.tar.gz (this command uncompresses the file foo.tar.gz into the cwd.)
top The top program provides a dynamic real-time view of a running system. It can display system summary information as well as a list of tasks currently being managed by the Linux system
example: me13m1001@Edison20]$ top -u user1 (this command shows all the processes owned by user1 in realtime in the terminal.)
uname Print certain system information such as: currently running kernel, hostname, etcetera.
example: me13m1001@Edison20]$ uname -a (this command prints information about the currently running kernel as well as other information.)
vi vi is, quite simply, a programmers terminal-based text editor. vi is on every Unix / Linux system you will ever encounter and is very powerful. It can be used for high level programming or simply to edit a text file, save and close it.
example: me13m1001@Edison20]$ vi mytextfile.txt (this command displays the text file mytextfile.txt in a terminal window and presents it for editing or reading.)
who Shows who is currently logged on to the system.
example: me13m1001@Edison20]$ who (this command displays verbose output of the users and processes logged into the system.)