🖥️ Scripter: Linux Shell Script Interpreter [C Project]

YouTube Demo & Output Samples

📝 Description

Scripter is a command interpreter written in C for Linux, designed to emulate core functionalities of a shell as part of an Operating Systems lab. It reads a script file line-by-line, interprets and executes each command using POSIX system calls. The project reinforces understanding of process management, file descriptor manipulation, piping, I/O redirection, and background execution.

The interpreter also supports an external command (mygrep), developed as a C program that mimics grep functionality, searching for strings within files.

🛠️ Languages and Utilities Used

• C
• GCC
• POSIX System Calls
• Linux

📷 Output Examples

Valid script execution:


Redirection and piping example:


Background command with PID output:


Mygrep execution:

📌 Features

• Validates script header (## Script de SSOO) and format.
• Executes sequential Linux commands line-by-line.
• Handles:
  • Simple commands with arguments.
  • Piped commands.
  • Input (<), output (>), and error (!>) redirections.
  • Background execution (&) with proper PID printing and zombie management.
  • Launches external command mygrep with same redirection/background capabilities.

📽️ Usage Instructions

1. Clone or Download the Project
2. Compile using Make:

make all       # builds scripter and the external 'mygrep' command

3. Execute with a script file:

./scripter example_script.txt    # the first line of script.txt must be '## Script de SSOO'

4. Clean binaries:

make clean      # cleans the build files

🧑‍💻 Authors

• Susana Ye Zhan
• Xinyi Yewu

This project is for educational purposes only. All rights reserved to Universidad Carlos III de Madrid.