Struct SpecifierContext 

pub struct SpecifierContext { /* private fields */ }

Context for expanding systemd specifiers

This contains the values that will be substituted when expanding specifiers in unit file values.

Implementations

impl SpecifierContext

pub fn new() -> Self

Create a new empty specifier context

pub fn set(&mut self, specifier: &str, value: &str)

Set a specifier value

Example

let mut ctx = SpecifierContext::new();
ctx.set("i", "instance");
ctx.set("u", "user");

pub fn get(&self, specifier: &str) -> Option<&str>

Get a specifier value

pub fn with_unit_name(unit_name: &str) -> Self

Create a context with common system specifiers

This sets up commonly used specifiers with their values:

• %n: Unit name (without type suffix)
• %N: Full unit name
• %p: Prefix (for template units)
• %i: Instance (for template units)

Example

let ctx = SpecifierContext::with_unit_name("foo@bar.service");
assert_eq!(ctx.get("N"), Some("foo@bar.service"));
assert_eq!(ctx.get("n"), Some("foo@bar"));
assert_eq!(ctx.get("p"), Some("foo"));
assert_eq!(ctx.get("i"), Some("bar"));

pub fn expand(&self, input: &str) -> String

Expand specifiers in a string

This replaces all %X patterns with their corresponding values from the context. %% is replaced with a single %.

Example

let mut ctx = SpecifierContext::new();
ctx.set("i", "myinstance");
ctx.set("u", "myuser");

let result = ctx.expand("/var/lib/%i/data/%u");
assert_eq!(result, "/var/lib/myinstance/data/myuser");

Trait Implementations

impl Clone for SpecifierContext

fn clone(&self) -> SpecifierContext

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for SpecifierContext

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for SpecifierContext

fn default() -> SpecifierContext

Returns the “default value” for a type.