iso53 / custom-linux-shell-with-multiprocess-management

MyShell is a meticulously crafted Linux shell program, implemented in C, tailored to operate seamlessly as a terminal application within your system. It encompasses a repertoire of custom commands, tailored responses, and error messaging functionalities.

MyShell

MyShell is a Linux shell program that i have written in C, designed to function as a terminal program on your system. MyShell includes custom commands, responses, and error messages.

Installation

To install MyShell, follow these steps:

• Clone the MyShell repository to your local machine.
• Open a terminal window and navigate to the MyShell directory.
• Compile MyShell by running the command make.
• Then type ./myshell

Usage

MyShell is designed to function like a standard Linux shell program, with a few custom commands added. Here are the custom commands included in MyShell:

• exit: Exits the MyShell program.
• bash: Calls the default bash shell and allows you to execute bash commands. Returns to MyShell when you type exit.
• execx: Runs the specified program a given number of times in the background, waiting for each process to finish before continuing. Additional parameters are passed to the program.
• writef: Writes the system time, process ID, and parent process ID to a file. If the file does not exist, it will be created. If the file exists, the data will be appended to the end of the file.
• cat message: Returns the message.
• clear: Clears the terminal screen.
• ls: Lists all files in the current directory.

Project Functions

Let's start with execx. execx command allows you to call a program any number of times. In this case its writef. Here is how you can do it:

execx -t [number] [program_name] [program_parameters]
writef -f [file_name]

these are the sytnaxes for execx and writef programs. Here how you can use these. Example:

execx -t 3 writef -f foo

this command will write the system time, pid and ppid value in a single line into the file named foo three times. You can also call execx program in execx program. Example:

execx -t 3 execx -t 5 writef -f foo

First execx command will call execx -t 5 writef -f foo three times and than second execx command will call writef -f foo 5 times. You can call as many nested commands as you want as long as you do not exceed the maximum number of arguments (100). You can change this value from the myshell.c file.

Error Handling

MyShell will return an error message if you enter an invalid command or if there is an error with a called program. You can always type help to get help.

First Time?

If you are confused while using the program, you can run the help command like this

help

or like this

help command_name