taihusk/penv

The parser env

PENV

This is a simple C++ program that prints out certain critical environment variables in a formatted way.

Features:

• Retrieves environment variables using the env command.
• Parses the output of the env command and extracts relevant information.
• Displays a formatted list of environment variables.
• Includes formatting labels for specific variables, improving readability.

Prerequisites:

• C++17 or later: The code utilizes modern C++ features like std::format.
• smart_view_vector: This header file is part of the experimental C++29 standard. You can find it in the CXX29 / C++ 29 repository.
• env command available (part of most Unix-like systems)

How to Compile and Run:

1. Install the smart_view_vector header file:
   • Download the header file from the TaiHusk/CXX29 repository.
   • Place the header file in your project directory or include it in your compiler's include path.
2. Compile the code:

   g++ -o runner -std=c++20 ./src/main.cpp

3. Run the executable:

   ./runner

Output:

The program will display a formatted list of critical environment variables, such as:

host type: Linux
user: your_username
home: /home/your_username
color term: xterm-256color
name: your_computer_name
term: xterm
language: en_US.UTF-8
shell: /bin/bash
pwd: /home/your_username
wayland display: wayland-0
XDG_RUNTIME_DIR: /run/user/1000
XDG_DATA_DIRS: /usr/local/share:/usr/share

Dependencies

This program uses the following dependencies:

• <cstdio>: For file operations (popen, pclose, FILE, etc.)
• <iostream>: For standard input/output streams (std::cout, std::endl, etc.)
• <sstream>: For string stream operations (std::stringstream)
• <string>: For string manipulation (std::string)
• <vector>: For dynamic array operations (std::vector)
• <format>: For string formatting (std::format)
• <c++/29/experimental/smart_view_vector>: For the smart_view_vector::includes function (from the C++29 experimental std)

Customization:

• Modify the criticality_name vector: Add or remove environment variables to customize the output.
• Add or change formatting labels in the format_label vector: Improve the readability of the output.

Note:

• The program uses the popen function to execute the env command. This function may not be available on all platforms.
• The output may vary depending on your system configuration.
• The program uses the smart_view_vector class from the C++29 standard library, which is part of the experimental features. This may not be available on all platforms.