Unix Basics

• a file is a collection of data with a name (a filename to be precise). Although it may be stored in seporate chuncks in different location on the hardware, programs will generaly work with a file as a single contiuous collection of data.

• a directory is construct for grouping and organizing files. In UNIX and Linux, directories can contain, files, other directories, links and devices. You may be use to calling directories folders or namespaces.

• a path is a way of nameing the location of a file, directory, link or device. Pathes can be relative or absolute and are often used as the prefix to a filename. For example, if I want to list the contents of a directory that is in my home directory called cheese, I can type:

  ls ~/cheese/

• a link is a filesystem pointer. You may be use to calling a link an alias or a shortcut

* a shell is the interactive command line interpreter to Unix. Typically you will have a prompt that looks like “%” or “~%”. Usually you will see it in an xterm which looks like a small terminal window.

• “ls, ls -a, ls -l, ls -la, etc. “: lists the files in your current working directory for that shell.
• cd directory : changes the current working directory to directory where directory may be a fully qualified path. A ~ indicates your home directory. ~bob indicates the home directory of bob.
• “rm filename” : removes the file filename where filesname may be a fully qualified path
• “cp source destination” : copies the file source to the file destination where source and destination may be fully qualified paths.
• “mv source destination” : the same as cp, but it moves the source file instead of copying it. mv can also be used to rename a file with mv oldname newmane
• “chmod file or directory” : changes the file or directory permissions for letter yourself and other people access your files. see man chmod for more info.

• Printing: the lpr command is the basic printing command. in your shell, type: “lpr filename " to print the file filename to the printer specified in printername or “lpq” to get a list of jobs sent to the printer.
• File compression: “gzip filename” will compress the file filename and give it the .gz name extension. “gzip -d filename.gz” or “gunzip filename.gz” will decompress the file and remove the .gz extension.

Help on any Unix command or system call can be found in the man pages. In your shell, type: “man command” and it will tell you all you ever wanted to know about how to use that command. There are two very useful books in the co-op bookstore on Unix. See the sign on the window side of the asprey lab. if you need help with emacs, pick up an emacs command reference page from thefolder above the terminal next to the asprey printer. If you are still having trouble, email or find Ben ()

In house User Info | UNIXhelp writen at the University of Edinburgh

Google Code University provides many helpful tutorials, including several for Linux, which can be found here: Tools 101