Struct CommandLine

Source

pub struct CommandLine { /* private fields */ }

Expand description

What the configuration flags on a command line said.

Every ZeroDDS program reads the same two flags, so they are parsed once here and the program sees only the arguments that are its own:

--config PATH / --config=PATH selects the base file. Given twice, it is refused: which of the two was meant is not the parser’s to decide.
--set PATH=VALUE / --set=PATH=VALUE sets one value above every file. Repeatable; a later one wins, --set +discovery.peers=… appends.
--check-config asks the program to validate and report the effective configuration and exit, without starting.

Parsing stops at --; what follows it belongs to the program.

Implementations§

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impl CommandLine

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pub fn extract(args: I) -> Result<(Self, Vec<String>), ConfigError>
where I: IntoIterator<Item = String>,

Takes the configuration flags out of args and returns the rest in their original order.

A long option in the rest written --opt=value comes back as --opt and value, so every program accepts both spellings the man pages use (before, amqp-, grpc- and corba-bridged and zerodds-ros2-shim answered --domain=3 with “unknown argument”, measured). What follows a -- is passed on untouched.

args excludes the program name.

§Errors

ConfigError::Usage for a flag without its value, a --set without =, an empty path, or --config given twice.

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pub fn push_set(&mut self, assignment: &str) -> Result<(), ConfigError>

Adds one PATH=VALUE, as a --set after the ones already given.

§Errors

ConfigError::Usage without = or with an invalid path.

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pub fn push_entry( &mut self, path: &str, fields: &[(&str, &str)], flag: &str, ) -> Result<(), ConfigError>

Appends one map of scalars to the list at path, for a program flag whose value is a list entry with several settings — a --set value is always one scalar. path is spelled as for --set (+types), flag is the flag as the operator wrote it and becomes the origin of every field. Entries are merged after every --set, in the order pushed.

§Errors

ConfigError::Usage for an invalid path, a path not written +name, or a field name that is not one path segment.

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pub fn check(&self) -> bool

Whether --check-config was given.

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pub fn with_config(self, path: impl Into<PathBuf>) -> Self

Selects a base file, as --config would.

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pub fn config_path(&self) -> Option<&Path>

The base file --config named.

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pub fn sets(&self) -> &[(String, String)]

Every --set, as (path, value), in the order given. The path keeps a leading + on its last segment.

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pub fn layer(&self) -> Result<Vec<Node>, ConfigError>

The --set values, one tree each, in the order given, each value’s origin naming its flag. Kept apart so that +name appends to the layers below instead of to an empty tree.

§Errors

ConfigError::Usage for an invalid path.

Source

pub fn apply(&self, config: &mut Config) -> Result<(), ConfigError>

Merges Self::layer onto config as its topmost source. Nothing is pushed when no --set was given, so Config::sources stays the list of what actually contributed.