Command Processor Bash Script

This script processes commands listed in a file and executes them sequentially. It is designed to simulate a shell-like interface for handling specific commands defined in the file.

Features

• File-based Command Processing: Reads commands from a specified file (in NEXLANG format, abbreviated as NL) and executes them.
• Supported Commands:
  • list: Lists files in the current directory.
  • list A: Lists all files, including hidden ones.
  • list L: Lists files with detailed information.
  • list AL or list LA: Combines list A and list L.
  • dir <directory>: Changes to the specified directory (e.g., dir /home/user).
  • wami: Displays the current working directory.
  • exit: Exits the script immediately.
• Error Handling: Provides meaningful error messages for invalid commands or missing files.

Usage

1. Save your commands in a text file (e.g., commands.nl), one command per line. Example:

   list
   list A
   dir /home
   wami
   exit
   

2. Run the script, passing the NL file as an argument:

   ./nexlang.sh commands.nl

3. The script will execute the commands in the order they are listed in the file.

Prerequisites

• Ensure the script is executable. You can make it executable with:

  chmod +x nexlang.sh

• The command file must exist, be in the NEXLANG format, and contain valid commands.

Error Messages

• File Not Found: If the specified file does not exist, the script will display:

  Error: File '<file_name>' not found.
  

• Directory Not Found: If the dir command points to a non-existent directory, the script will display:

  Error: Directory '<directory>' not found.
  

• Unknown Command: For unsupported commands, the script will display:

  command.<command>: Not found
  

Example

Given a file example_commands.nl with the following content:

list
list A
dir /nonexistent
dir /home
wami
exit

Run the script:

./nexlang.sh example_commands.nl

Output:

<list of files>
<list of all files>
Error: Directory '/nonexistent' not found.
Changed directory to /home
/home