clap/examples/tutorial_derive/04_04_custom.rs

91 lines
2.5 KiB
Rust

use clap::error::ErrorKind;
use clap::{CommandFactory, Parser};
#[derive(Parser)]
#[command(author, version, about, long_about = None)]
struct Cli {
/// set version manually
#[arg(long, value_name = "VER")]
set_ver: Option<String>,
/// auto inc major
#[arg(long)]
major: bool,
/// auto inc minor
#[arg(long)]
minor: bool,
/// auto inc patch
#[arg(long)]
patch: bool,
/// some regular input
input_file: Option<String>,
/// some special input argument
#[arg(long)]
spec_in: Option<String>,
#[arg(short)]
config: Option<String>,
}
fn main() {
let cli = Cli::parse();
// Let's assume the old version 1.2.3
let mut major = 1;
let mut minor = 2;
let mut patch = 3;
// See if --set-ver was used to set the version manually
let version = if let Some(ver) = cli.set_ver.as_deref() {
if cli.major || cli.minor || cli.patch {
let mut cmd = Cli::command();
cmd.error(
ErrorKind::ArgumentConflict,
"Can't do relative and absolute version change",
)
.exit();
}
ver.to_string()
} else {
// Increment the one requested (in a real program, we'd reset the lower numbers)
let (maj, min, pat) = (cli.major, cli.minor, cli.patch);
match (maj, min, pat) {
(true, false, false) => major += 1,
(false, true, false) => minor += 1,
(false, false, true) => patch += 1,
_ => {
let mut cmd = Cli::command();
cmd.error(
ErrorKind::ArgumentConflict,
"Can only modify one version field",
)
.exit();
}
};
format!("{major}.{minor}.{patch}")
};
println!("Version: {version}");
// Check for usage of -c
if let Some(config) = cli.config.as_deref() {
let input = cli
.input_file
.as_deref()
// 'or' is preferred to 'or_else' here since `Option::as_deref` is 'const'
.or(cli.spec_in.as_deref())
.unwrap_or_else(|| {
let mut cmd = Cli::command();
cmd.error(
ErrorKind::MissingRequiredArgument,
"INPUT_FILE or --spec-in is required when using --config",
)
.exit()
});
println!("Doing work using input {input} and config {config}");
}
}