mirror of https://github.com/encounter/nod-rs.git
65 lines
2.3 KiB
Rust
65 lines
2.3 KiB
Rust
// Originally from https://gist.github.com/suluke/e0c672492126be0a4f3b4f0e1115d77c
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//! Extend `argp` to be better integrated with the `cargo` ecosystem
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//!
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//! For now, this only adds a --version/-V option which causes early-exit.
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use std::ffi::OsStr;
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use argp::{parser::ParseGlobalOptions, EarlyExit, FromArgs, TopLevelCommand};
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struct ArgsOrVersion<T>(T)
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where T: FromArgs;
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impl<T> TopLevelCommand for ArgsOrVersion<T> where T: FromArgs {}
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impl<T> FromArgs for ArgsOrVersion<T>
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where T: FromArgs
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{
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fn _from_args(
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command_name: &[&str],
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args: &[&OsStr],
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parent: Option<&mut dyn ParseGlobalOptions>,
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) -> Result<Self, EarlyExit> {
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/// Also use argp for catching `--version`-only invocations
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#[derive(FromArgs)]
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struct Version {
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/// Print version information and exit.
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#[argp(switch, short = 'V')]
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pub version: bool,
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}
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match Version::from_args(command_name, args) {
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Ok(v) => {
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if v.version {
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println!(
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"{} {} {}",
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command_name.first().unwrap_or(&""),
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env!("CARGO_PKG_VERSION"),
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env!("GIT_COMMIT_SHA"),
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);
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std::process::exit(0);
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} else {
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// Pass through empty arguments
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T::_from_args(command_name, args, parent).map(Self)
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}
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}
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Err(exit) => match exit {
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EarlyExit::Help(_help) => {
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// TODO: Chain help info from Version
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// For now, we just put the switch on T as well
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T::from_args(command_name, &["--help"]).map(Self)
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}
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EarlyExit::Err(_) => T::_from_args(command_name, args, parent).map(Self),
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},
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}
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}
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}
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/// Create a `FromArgs` type from the current process’s `env::args`.
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///
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/// This function will exit early from the current process if argument parsing was unsuccessful or if information like `--help` was requested.
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/// Error messages will be printed to stderr, and `--help` output to stdout.
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pub fn from_env<T>() -> T
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where T: TopLevelCommand {
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argp::parse_args_or_exit::<ArgsOrVersion<T>>(argp::DEFAULT).0
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}
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