Unix-Shell

Build a preliminary command-line interface. Support user command and batch mode

Commmand Mode

For instance, when user enter the main program

./wish
>

This will prompt user inputs

Batch Mode

The user could designate files that contains commands that could be fetched into the shell

./wish commands.txt

Add New Features

Now the shell support redirection and if statements For example

ls -la /tmp > output

Will redirect the output to tmp

if a = 1 then ls > output 

Suppose a is a program, the shell will evalute the condition first in order to finish the remaining part.