C-Shell: A Feature-Rich Linux Shell Implementation in C

Welcome to C-Shell, a powerful and customizable Unix shell implemented in the C programming language. This project showcases the versatility of system calls in Linux, offering a robust and user-friendly shell experience.

Features:

• System Calls Galore: Leverage the strength of various Linux system calls to achieve efficient process management, file manipulation, and I/O operations.

• Interactive Command Line: Enjoy an interactive command-line interface that supports a wide array of commands, providing a seamless user experience.

• Customization Options: Tailor the shell to your needs with customizable configurations, aliases, and prompt settings.

• Process Management: Efficiently handle processes with built-in functionalities for background processes, job control, and signal handling.

• File Operations: Leverage file-related system calls for file manipulation, redirection, and piping to enhance the shell's file-handling capabilities.

Getting Started:

• Clone the Repository:
  git clone https://github.com/your-username/C-Shell.git
cd C-Shell

• Compile and Run:
  make
./a.out

Description

• header.h contains all the header files being used in this codebase along with global variables/arrays which are being used using extern to use it in different files.
• main.c is the main C file for this shell from where all the different functions get called accordingly.
• call.c and call.h are used to call other functions.
• prompt.c and prompt.h handles the display of command prompt in the following format:

  <Username@SystemName:~>
  

• warp.c and warp.h handles changing the directory that the shell is currently in. It also prints the full path of working directory after changing. Follwing flags are also implemented with this: ., ~, .., -.
• proclore.c and proclore.h is used to obtain information regarding a process. If an argument is missing, print the information of your shell.
• pastevents.c and pastevents.h handle the storing of previous command, so that user can access the past 15 commands run on shell and also execute then. pastevents.txt stores those commands.
• peek.c and peek.h function like the ls command in terminal. It lists all the files and directories in the specified directories in lexicographic order. It suppors the following flags:

-l : displays extra information
-a : displays all files, including hidden files

• seek.h and seek.c looks for a file/directory in the specified target directory (or current if no directory is specified). It returns a list of relative paths (from target directory) of all matching files/directories (files in green and directories in blue) separated with a newline character.
• foreground.c and foreground.h handle the system foreground processes, such as sleep, echo, etc.
• background.c and background.h handle the system background processes.

Assumptions

• paths/names will not contain any whitespace characters.
• pastevents.txt is already created. The above codebase does not create a new file if its not present. It assumes that the textfile is present already.
• Shell is exited when you run the command "exit" and it is saved in pastevents.txt.
• With peek if argument is provided, it is always a directory (not a file).
• There won't be more than 4096 files/directories in a directory.
• For seek, executables are not displayed.
• Path length of any path won't exceed 200 characters.
• There won't be more than 4096 processes running in the background.