// Note: this requires the `cargo` feature use std::path::PathBuf; use clap::{arg, command, value_parser, ErrorKind}; fn main() { // Create application like normal let mut cmd = command!() // Add the version arguments .arg(arg!(--"set-ver" "set version manually").required(false)) .arg(arg!(--major "auto inc major")) .arg(arg!(--minor "auto inc minor")) .arg(arg!(--patch "auto inc patch")) // Arguments can also be added to a group individually, these two arguments // are part of the "input" group which is not required .arg(arg!([INPUT_FILE] "some regular input").value_parser(value_parser!(PathBuf))) .arg( arg!(--"spec-in" "some special input argument") .required(false) .value_parser(value_parser!(PathBuf)), ) // Now let's assume we have a -c [config] argument which requires one of // (but **not** both) the "input" arguments .arg( arg!(config: -c ) .required(false) .value_parser(value_parser!(PathBuf)), ); let matches = cmd.get_matches_mut(); // 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) = matches.get_one::("set-ver") { if matches.is_present("major") || matches.is_present("minor") || matches.is_present("patch") { 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) = ( matches.is_present("major"), matches.is_present("minor"), matches.is_present("patch"), ); match (maj, min, pat) { (true, false, false) => major += 1, (false, true, false) => minor += 1, (false, false, true) => patch += 1, _ => { cmd.error( ErrorKind::ArgumentConflict, "Can only modify one version field", ) .exit(); } }; format!("{}.{}.{}", major, minor, patch) }; println!("Version: {}", version); // Check for usage of -c if matches.is_present("config") { let input = matches .get_one::("INPUT_FILE") .or_else(|| matches.get_one::("spec-in")) .unwrap_or_else(|| { cmd.error( ErrorKind::MissingRequiredArgument, "INPUT_FILE or --spec-in is required when using --config", ) .exit() }) .display(); println!( "Doing work using input {} and config {}", input, matches.get_one::("config").unwrap().display() ); } }