systemd-unit-edit

A lossless parser and editor for systemd unit files as specified by the systemd.syntax(7) and systemd.unit(5) specifications.

This library preserves all whitespace, comments, and formatting while providing a structured way to read and modify systemd unit files.

Features

• Lossless parsing: All whitespace, comments, and formatting are preserved
• Systemd unit file support: Full support for the systemd unit file format
• Line continuation support: Handles backslash line continuations
• Comment support: Supports both # and ; style comments
• Multiple values: Supports multiple entries with the same key (common in systemd)

Example

use systemd_unit_edit::SystemdUnit;
use std::str::FromStr;

let input = r#"[Unit]
Description=Test Service
After=network.target

[Service]
Type=simple
ExecStart=/usr/bin/test
"#;

let unit = SystemdUnit::from_str(input).unwrap();

// Read sections
for section in unit.sections() {
    println!("Section: {}", section.name().unwrap());
    for entry in section.entries() {
        println!("  {} = {}", entry.key().unwrap(), entry.value().unwrap());
    }
}

// Modify values
let mut service_section = unit.get_section("Service").unwrap();
service_section.set("Type", "forking");

// Add new entries
service_section.add("ExecReload", "/bin/kill -HUP $MAINPID");

// Write back to string
println!("{}", unit);

API

SystemdUnit

The root type representing a parsed systemd unit file.

• SystemdUnit::from_str(text) - Parse from a string
• SystemdUnit::from_file(path) - Load from a file
• unit.sections() - Iterate over all sections
• unit.get_section(name) - Get a specific section by name
• unit.add_section(name) - Add a new section
• unit.text() - Convert back to string (lossless)
• unit.write_to_file(path) - Write to a file

Section

Represents a section in a unit file (e.g., [Unit], [Service]).

• section.name() - Get the section name
• section.entries() - Iterate over all entries
• section.get(key) - Get the first value for a key
• section.get_all(key) - Get all values for a key (for multi-value keys)
• section.set(key, value) - Set a value (replaces first occurrence)
• section.add(key, value) - Add a value (appends even if key exists)
• section.remove(key) - Remove the first entry with the key
• section.remove_all(key) - Remove all entries with the key

Entry

Represents a key-value entry in a section.

• entry.key() - Get the key name
• entry.value() - Get the value (with line continuations processed)
• entry.raw_value() - Get the raw value as it appears in the file

License

Apache-2.0