Some of UNIX commands

Here you go you can find here some basic UNIX commands 

Directories

• / : “root” directory
• /usr : directory usr (sub-directory of / "root" directory)
• mkdir dirname : make a new directory
• cd : Change current directory to your HOME directory.
• cd dirname : change directory. 
• pwd : show the current directory 

Files 

• ls : lists your files
  ls -l : lists your files in 'long format'.
  ls -a : lists all files, including the ones whose filenames begin in a dot.
• more filename : shows the first part of a file, just as much as will fit on one screen. Just hit the space bar to see more or q to quit.
• emacs filename : is an editor that lets you create and edit a file.
• mv filename1 filename2 : moves a file
• cp filename1 filename2 : copies a file
• rm filename : removes a file.
• diff filename1 filename2 : compares files.
• wc filename : tells you how many lines, words, and characters there are in a file
• chmod options filename : lets you change the read, write, and execute permissions on your files.
• File Compression
• gzip filename : compresses files.
• gunzip filename : uncompresses files compressed by gzip.
• gzcat filename : lets you look at a gzipped file without actually having to gunzip
• printing
• lpr filename : print.
• lpq : check out the printer queue.
• lprm jobnumber : remove something from the printer queue.

Viewing and editing files

• cat filename : Dump a file to the screen in ascii.
• more filename : Progressively dump a file to the screen.
• less filename : Like more.
• vi filename : Edit a file using the vi editor.
• emacs filename : Edit a file using the emacs editor.
• head filename : Show the first few lines of a file.
• head -n  filename : Show the first n lines of a file.
• tail filename : Show the last few lines of a file.
• tail -n filename : Show the last n lines of a file.

Changing file permissions and attributes

• chmod 755 file : Changes the permissions of file to be rwx for the owner, and rx for  the group and the world. (7 = rwx = 111 binary. 5 = r-x = 101 binary)
• chgrp user file : Makes file belong to the group user.
• chown cliff file : Makes cliff the owner of file.
• chown -R cliff dir : Makes cliff the owner of dir and everything in its directory tree.

Finding things

• ff : find files anywhere on the system.
• grep string filename(s) : looks for the string in the files.

About other people

• w : tells you who's logged in, and what they're doing.
• who : tells you who's logged on, and where they're coming from.
• finger username : gives you lots of information about that user.
• last -1 username : tells you when the user last logged on and off and from where.
• talk username : lets you have a conversation with another user
• write username : lets you exchange one-line messages with another user
• elm : lets you send e-mail messages to people around the world

About yourself

• whoami : returns your username.
• passwd : lets you change your password.
• ps -u yourusername : lists your processes.
• kill PID : kills the processes with the ID you gave.
• quota -v : show what your disk quota is, how much you're using.
• du filename : shows the disk usage of the files and directories.
• last yourusername : lists your last logins.

Connecting

• nn : allows you to read news.
•  rlogin hostname : lets you connect to a remote host
• telnet hostname : lets you connect to a remote host.
• ftp hostname : lets you download files from a remote host.
• lynx : lets you browse the web from an ordinary terminal.

Miscellaneous tools

• date : shows the current date and time.
• cal : shows a calendar of the current month.

I hope this article was helpful and for any suggestions leave a comment bellow