MyShell

MyShell is a custom Unix-like shell implemented in C that provides a set of built-in commands and supports the execution of external commands. It includes several built-in commands for common file operations and environment manipulations, as well as the ability to handle standard bash commands. The shell supports IO redirection and Piping.

Features

• Built-in Commands: Includes custom commands such as mycp, mymv, mypwd, myecho, myhelp, myexit, mytype, envir, myfree, myuptime.
• Support for External Commands: Can execute standard bash commands and other external programs.
• **Supports piping: allowing users to connect the output of one command directly to the input of another command.
• **Supports redirection: enabling users to redirect the output and error of commands to files or other locations, and to use files as input for commands.
• Command-Line Interface: Interactive shell environment where you can execute commands, view help messages, and manage files.

Built-in Commands

Here’s a brief overview of each built-in command:

• mycp <source> <destination>: Copies a file from <source> to <destination>.
• mymv <source> <destination>: Moves a file from <source> to <destination>.
• mypwd: Prints the current working directory.
• myecho <message>: Prints <message> to the standard output.
• myhelp [command]: Displays help information for built-in commands. If no command is specified, lists all available commands.
• myexit: Exits the shell.
• mytype <command>: Displays the type of the specified command (built-in or external).
• envir [variable]: Prints all environment variables if no argument is provided. If a variable name is specified, prints the value of that variable.

Usage

Adding MyShell to Your PATH

To execute MyShell from any location, add its directory to your PATH environment variable:

1. Compile MyShell (see the next section for instructions).

2. Move the compiled executable to a directory included in your PATH, or add its directory to PATH.

   Example to add the directory to PATH:

   echo 'export PATH="$PATH:/home/user/Desktop/my_shell"' >> ~/.bashrc
   source ~/.bashrc
   

Compiling MyShell

To compile MyShell with its various source files, use the following gcc command:

gcc -o my_shell program.c mycp.c mymv.c mypwd.c myecho.c myhelp.c mycd.c envir.c external.c mytype.c piping.c myfree.c myuptime.c redirection.c terminate.c -lreadline -lhistory 

Examples

Copying a File

mycp file1.txt file2.txt

Moving a File

mymv file1.txt file2.txt

Printing the Current Directory

mypwd

Echoing a Message

 myecho "Hello, world!"

Getting Help

 myhelp

 myhelp mycp

Exiting the Shell

myexit

Checking Command Type

mytype mycp

Viewing Environment Variables

envir
envir PATH

pipe and redirection

ls | grep p > output.txt