Function Logger 

pub fn Logger()

Sets up the global logger for the application.

This function initializes the env_logger crate with custom formatting and configuration for the build system. It:

• Reads the RUST_LOG environment variable to set the log level
• Defaults to info level if the variable is not set
• Provides color-coded output for different log levels
• Formats messages with a consistent [Build] prefix

Log Levels

Supported log levels (in increasing verbosity):

• error - Only error messages
• warn - Warning messages and errors
• info - Informational messages, warnings, and errors (default)
• debug - Debug messages and above
• trace - Trace messages and above (very verbose)

Log Format

Messages are formatted as:

[Build] [LEVEL]: message content

Where LEVEL is color-coded:

• [ERROR] - Red, bold
• [WARN] - Yellow, bold
• [INFO] - Green
• [DEBUG] - Blue
• [TRACE] - Magenta

Environment Configuration

The log level is controlled by the RUST_LOG environment variable:

Set minimum log level to debug
export RUST_LOG=debug

Enable debug logs only for the Build module
export RUST_LOG=Build=debug

Enable trace logs for Build::Toml module
export RUST_LOG=Build::Toml=trace

Usage Example

use crate::Maintain::Source::Build::Logger;
use log::{info, error};

// Initialize logger first
Logger();

// Now logging is available throughout the application
info!("Build process started");
error!("Build process failed");

Module-Specific Logging

The build system uses the following logging targets:

• Build - General build orchestration messages
• Build::Guard - File backup and restoration messages
• Build::Toml - TOML editing messages
• Build::Json - JavaScriptObjectNotation editing messages
• Build::Exec - Command execution messages

You can set different log levels for each target:

export RUST_LOG=Build=info,Build::Toml=debug,Build::Exec=warn

Thread Safety

The global logger initialized by this function is thread-safe and can be used from multiple threads concurrently without additional synchronization.

Implementation Notes

This function uses env_logger::Builder to construct the logger with custom formatting. The formatter uses the colored crate to apply color coding based on the log level.

The logger is typically called once at program startup, before any other operations that might generate log messages.