Unix Command Review

Important UNIX conventions

1, Command Format

Commands must be typed all on one line, with spaces between the command, options, and arguments.

2,Naming Files

Filenames consist of alphanumeric characters, underscores, dashes, and periods.  DO NOT use spaces or other punctuation in filenames!

3,Case Sensitivity

Commands and filenames in UNIX are case sensitive!!

4,Filename Completiom

After typeing a unique prefix of a filename, pressing the Tab key will cause the Unix shell to complete the filename.

5,Command Editing

The up arrow key will retrieve a previous command. This command may be edited using the left/right arrow keys and backspace.

6,^C (control-C)

In UNIX, this terminates a currently running process when typed in the window the process is running in.

7,^Z (control-Z)

In UNIX, this sends a process to run in the background. The process will still exist; you just won't see it. Type "fg" to bring it back so that you can exit properly. Don't exit Unix with processes running in the background.

Working with Directories

0,Directory Notes

In UNIX pathnames, slashes (/) separate the directory and filenames
e.g. /home/mcb/myfile.txt  [ here home and mcb are directories and myfile.txt is a file ]. The current directory is referred to as . (‘dot’) and the parent directory is referred to as .. (‘dot dot’). The home directory is called ~ (‘tilde’).

1,Display present working directory

pwd   echo present working directory on screen

2,Change directory

cd dirname     Change current working directory to specific directory.

cd or cd ~    Go to your home directory, i.e. the directory you start in when you login.

cd ..   Go to the parent of the directory you are in now [ move up by 1 directory ]

3,Create/Delete directory

mkdir dirname     Creates a directory called dirname in the current directory

rmdir dirname     Delete (remove) empty directory

rm –r dirname     Delete directory and the content inside it(files,subdirectoris)

4,Lists directory contents

ls dirname    lists contents within specific directory

ls –l            shows a "long", detailed listing

ls –a            lists all of contents ,including hide directoris,files(starting with “.”)