crab

The crab shell

Building and installing

To build and install crab, run the following

make clean
sudo make install

This will install the crab shell and its associated manpages.

To build the crab shell without installing, use the following

make clean
make

The shell will be located in bin/crab

To run the unit tests, use the following (note that you must use make before you do this)

make debug
./test_crab

Once crab is installed, it can be uninstalled with

sudo make uninstall

Running

Once crab is installed, you can run it with

crab

Implemented Commands

Feature	Description
cd	Changes current directory to
exit (or quit)	Exits the crab shell
autocomplete (press tab)	Press tab when typing a directory name to have the shell auto-complete it
history <# of cmds>	Displays a list of recently used commands
pwd	Displays the path to the current directory
colour	Switches the colour of the text in the shell
ad	Create and navigate through aliases. for detailed usage instructions, see the # Alias section

Alias

Set an alias with ad (see commands below) and cd to that alias

Command	Effect
ad	0 args - sets alias [prev] equal to current directory
ad [name]	1 args - sets alias [name] equal to current directory
ad [name] [dir]	2 args - sets alias [name] equal to [dir]
ad print	print all aliases currently assigned
ad findn [name]	print directory associated with [name]
ad findd [dir]	print names associated with [dir]
ad save	save all alias to file to be used in other sessions
ad deletelog	delete alias.log and its contents
ad remove [name]	Remove an alias with [name]
ad reset	reset all alias for this current session
cd [name]	change directory to the directory corresponding to [name]

Colour

To change the colour of the input/output text use the following command:

colour <colour name>

Below are the valid options for <colour name>:

reset (default colour)
red
magenta
yellow
green
blue
cyan
white

History

Whenever you input a command, it will be stored for later access.

History will be stored in a file called cmdhist.txt so that it may persist through sessions.

Please note that the .txt file will be stored in whichever directory you run the crab shell from. If you switch directories and run the shell from a different one than you normally use, you will not have access to your full command history, and the two directories will contain separate cmdhist.txt files.

After you type a history command, a list of commands will be displayed.

Index numbers will be displayed next to the commands. If your very next input is a valid index number (within the range of displayed indices), the corresponding command will be run.

To access history,

Command	Effect
history	If no argument is given, 10 commands will be displayed by default
history [# of commands]	If an integer argument is specified, that number of commands will be displayed.

Pipes

Pipes can be used to take the output of one command and use it as the input of another command. Crab shell supports any number of piped commands

Example:

ls | grep test