ini-preserve

Format-preserving INI parser for Rust.

Read, modify and write back INI files without losing comments, ordering or formatting.

Unlike most INI parsers that discard comments and reorder sections when writing, ini-preserve keeps the original file structure intact. Only the values you explicitly change are modified. Everything else (comments, blank lines, key order, spacing around =) is preserved.

Community & support

Questions, bug reports, beta testing, or just want to chat? Join the Discord:

Features

• Round-trip safe — parse and write back produces identical output
• Comments preserved — ; and # comment lines are kept as-is
• Ordering preserved — sections and keys stay in their original order
• Spacing preserved — Key=Value, Key = Value, Key =Value all keep their style
• Semicolons in values — Key = foo;bar works correctly (; is not treated as inline comment)
• Atomic writes — save() writes to a temp file then renames
• No dependencies — pure Rust, no external crates
• Simple API — load(), get(), set(), save()

Usage

use ini_preserve::Ini;

// Load an existing INI file
let mut ini = Ini::load("config.ini").unwrap();

// Read values
if let Some(value) = ini.get("Player", "Width") {
    println!("Width = {}", value);
}

// Modify values (only changed lines are rewritten)
ini.set("Player", "Width", "3840");
ini.set("Player", "Height", "2160");

// Save back — comments and formatting preserved
ini.save("config.ini").unwrap();

Why?

Many applications (like VPinballX) generate INI files with extensive comments documenting every setting and its default value. Using a standard INI parser to modify one value destroys all those comments. ini-preserve solves this by treating the file as a sequence of lines and only modifying the specific lines that need to change.

License

MIT