Custom Shell Implementation

This is a simple shell implementation in C created as part of an assignment. The shell supports basic commends like cd, help, input/output redirection, and some custom commends (add, mul, factorial,strrev etc.. ) that are executed from user-defined executable files. N.B : To execute any user defined command you need to keep command.c file in a subdirectory named 'ExecutableFiles' and add the program name at customCommend[] character array of convertCMD() function

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Features

1. Custom commends:

   • add: Adds two numbers.
   • mul: Multiplies two numbers.
   • factorial: Computes the Factorial of a given number.
   • strrev: Computes the Reverse of a given string.

2. Built-in commends:

   • cd <directory>: Change the current working directory.
   • help: Displays the Bash manual.
   • exit or clear: Terminates the shell.
   • ls: Shows fiels and folders of the directory

3. Input/Output Redirection:

   • Redirect input using <commend> < <sourcefile.txt>.
   • Redirect output using <commend> > <destinationfile.txt>.

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How to Compile and Run the Shell

1. Clone the Repository or Navigate to the Project Directory.

2. Compile the Program:

   • The project includes a Makefile to automate the compilation process. You can compile the program using the following commend:

     make

3. Run the Shell:

   • Once compiled, you can run the shell with the following commend:

     ./shell

4. Use the Custom and Built-in commends:

   • You can use any of the custom commends (add, mul, factorial) or built-in commends (cd, help, exit) from the shell prompt.

5. To Terminate the Shell:

   • Use the exit or clear commend to exit the shell.

6. Clean the Program:

   • Clean all executable files by using:

     make clean

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Example Usage

1. Custom commend - add:

   add 5 7

2. Custom commend - mul:

   mul 5 7

3. Custom commend - factorial:

   factorial 5 7

4. Custom commend - strrev:

   strrev testingString

5. Custom commend - input redirection (Assum we have sourcefile.txt):

   add < sourcefile.txt

6. Custom commend - output redirection :

   add 4 5 > detinationfile.txt

Visualization of Process Tree