cli: migrate from gumdrop to clap v3 (#379)

`gumdrop` was originally chosen for its minimalist set of dependencies,
but `clap` v3 has a slimmed down set of dependencies and better UX.

Cargo.lock

@@ -105,6 +105,45 @@ dependencies = [
  "inout",
 ]
 
+[[package]]
+name = "clap"
+version = "3.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d2dbdf4bdacb33466e854ce889eee8dfd5729abf7ccd7664d0a2d60cd384440b"
+dependencies = [
+ "atty",
+ "bitflags",
+ "clap_derive",
+ "clap_lex",
+ "indexmap",
+ "lazy_static",
+ "strsim",
+ "termcolor",
+ "textwrap",
+]
+
+[[package]]
+name = "clap_derive"
+version = "3.1.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "25320346e922cffe59c0bbc5410c8d8784509efb321488971081313cb1e1a33c"
+dependencies = [
+ "heck",
+ "proc-macro-error",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "clap_lex"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a37c35f1112dad5e6e0b1adaff798507497a18fceeb30cceb3bae7d1427b9213"
+dependencies = [
+ "os_str_bytes",
+]
+
 [[package]]
 name = "const-oid"
 version = "0.7.1"
@@ -332,24 +371,16 @@ dependencies = [
 ]
 
 [[package]]
-name = "gumdrop"
+name = "hashbrown"
-version = "0.8.1"
+version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5bc700f989d2f6f0248546222d9b4258f5b02a171a431f8285a81c08142629e3"
+checksum = "ab5ef0d4909ef3724cc8cce6ccc8572c5c817592e9285f5464f8e86f8bd3726e"
-dependencies = [
- "gumdrop_derive",
-]
 
 [[package]]
-name = "gumdrop_derive"
+name = "heck"
-version = "0.8.1"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "729f9bd3449d77e7831a18abfb7ba2f99ee813dfd15b8c2167c9a54ba20aa99d"
+checksum = "2540771e65fc8cb83cd6e8a237f70c319bd5c29f78ed1084ba5d50eeac86f7f9"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn",
-]
 
 [[package]]
 name = "hermit-abi"
@@ -375,6 +406,16 @@ version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 
+[[package]]
+name = "indexmap"
+version = "1.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0f647032dfaa1f8b6dc29bd3edb7bbef4861b8b8007ebb118d6db284fd59f6ee"
+dependencies = [
+ "autocfg",
+ "hashbrown",
+]
+
 [[package]]
 name = "inout"
 version = "0.1.3"
@@ -511,6 +552,12 @@ version = "0.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "624a8340c38c1b80fd549087862da4ba43e08858af025b236e509b6649fc13d5"
 
+[[package]]
+name = "os_str_bytes"
+version = "6.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "029d8d0b2f198229de29dca79676f2738ff952edf3fde542eb8bf94d8c21b435"
+
 [[package]]
 name = "p256"
 version = "0.11.0"
@@ -613,6 +660,30 @@ version = "0.2.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "eb9f9e6e233e5c4a35559a617bf40a4ec447db2e84c20b55a6f83167b7e57872"
 
+[[package]]
+name = "proc-macro-error"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c"
+dependencies = [
+ "proc-macro-error-attr",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "version_check",
+]
+
+[[package]]
+name = "proc-macro-error-attr"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1be40180e52ecc98ad80b184934baf3d0d29f979574e439af5a55274b35f869"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "version_check",
+]
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.39"
@@ -824,6 +895,12 @@ dependencies = [
  "der 0.6.0",
 ]
 
+[[package]]
+name = "strsim"
+version = "0.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
+
 [[package]]
 name = "subtle"
 version = "2.4.1"
@@ -859,6 +936,12 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "textwrap"
+version = "0.15.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1141d4d61095b28419e22cb0bbf02755f5e54e0526f97f1e3d1d160e60885fb"
+
 [[package]]
 name = "thiserror"
 version = "1.0.31"
@@ -1018,8 +1101,8 @@ dependencies = [
 name = "yubikey-cli"
 version = "0.6.0-pre"
 dependencies = [
+ "clap",
  "env_logger",
- "gumdrop",
  "lazy_static",
  "log",
  "sha2 0.9.9",

cli/Cargo.toml

@@ -15,7 +15,7 @@ edition = "2021"
 rust-version = "1.56"
 
 [dependencies]
-gumdrop = "0.8"
+clap = { version = "3", features = ["derive"] }
 env_logger = "0.9"
 lazy_static = "1"
 log = "0.4"

cli/src/bin/yubikey/main.rs

@@ -8,9 +8,9 @@
     unused_qualifications
 )]
 
-use gumdrop::Options;
+use clap::Parser;
 use yubikey_cli::commands::YubiKeyCli;
 
 fn main() {
-    YubiKeyCli::parse_args_default_or_exit().run();
+    YubiKeyCli::parse().run()
 }

cli/src/commands.rs

@@ -4,62 +4,25 @@ pub mod readers;
 pub mod status;
 
 use self::{readers::ReadersCmd, status::StatusCmd};
-use crate::terminal::{self, STDOUT};
+use crate::terminal;
-use gumdrop::Options;
+use clap::Parser;
-use std::{
+use std::{env, process::exit};
-    env,
+use termcolor::ColorChoice;
-    io::{self, Write},
-    process::exit,
-};
-use termcolor::{ColorChoice, ColorSpec, WriteColor};
 use yubikey::{Serial, YubiKey};
 
 /// The `yubikey` CLI utility
-#[derive(Debug, Options)]
+#[derive(Debug, Parser)]
 pub struct YubiKeyCli {
-    /// Obtain help about the current command
+    /// Serial number of the YubiKey to connect to
-    #[options(short = "h", help = "print help message")]
+    #[clap(short = 's', long = "serial")]
-    pub help: bool,
-
-    /// Specify the serial number of the YubiKey to connect to
-    #[options(
-        short = "s",
-        long = "serial",
-        help = "serial number of the YubiKey to connect to"
-    )]
     pub serial: Option<Serial>,
 
     /// Subcommand to execute.
-    #[options(command)]
+    #[clap(subcommand)]
-    pub command: Option<Commands>,
+    pub command: Commands,
 }
 
 impl YubiKeyCli {
-    /// Print usage information
-    pub fn print_usage() -> io::Result<()> {
-        let mut stdout = STDOUT.lock();
-        stdout.reset()?;
-
-        let mut bold = ColorSpec::new();
-        bold.set_bold(true);
-
-        stdout.set_color(&bold)?;
-        writeln!(
-            stdout,
-            "{} {}",
-            env!("CARGO_PKG_NAME"),
-            env!("CARGO_PKG_VERSION")
-        )?;
-        stdout.reset()?;
-
-        writeln!(stdout, "{}", env!("CARGO_PKG_AUTHORS"))?;
-        writeln!(stdout, "{}", env!("CARGO_PKG_DESCRIPTION").trim())?;
-        writeln!(stdout)?;
-        writeln!(stdout, "{}", Commands::usage())?;
-
-        Ok(())
-    }
-
     /// Run the underlying command type or print usage info and exit
     pub fn run(&self) {
         // TODO(tarcieri): make this more configurable
@@ -70,10 +33,7 @@ impl YubiKeyCli {
             env_logger::builder().format_timestamp(None).init();
         }
 
-        match &self.command {
+        self.command.run(self.yubikey_init())
-            Some(cmd) => cmd.run(self.yubikey_init()),
-            None => Self::print_usage().unwrap(),
-        }
     }
 
     /// Initialize the YubiKey client driver
@@ -92,22 +52,18 @@ impl YubiKeyCli {
 }
 
 /// Subcommands of this application
-#[derive(Debug, Options)]
+#[derive(Debug, Parser)]
 pub enum Commands {
-    /// `help` subcommand
-    #[options(help = "show help for a command")]
-    Help(HelpOpts),
-
     /// `version` subcommand
-    #[options(help = "display version information")]
+    #[clap(about = "display version information")]
     Version(VersionOpts),
 
     /// `readers` subcommand
-    #[options(help = "list detected readers")]
+    #[clap(about = "list detected readers")]
     Readers(ReadersCmd),
 
     /// `status` subcommand
-    #[options(help = "show yubikey status")]
+    #[clap(about = "show yubikey status")]
     Status(StatusCmd),
 }
 
@@ -115,7 +71,6 @@ impl Commands {
     /// Run the given command
     pub fn run(&self, yubikey: YubiKey) {
         match self {
-            Commands::Help(help) => help.run(),
             Commands::Version(version) => version.run(),
             Commands::Readers(list) => list.run(),
             Commands::Status(status) => status.run(yubikey),
@@ -123,28 +78,8 @@ impl Commands {
     }
 }
 
-/// Help options
-#[derive(Debug, Options)]
-pub struct HelpOpts {
-    #[options(free, help = "subcommand to get help for")]
-    free: Vec<String>,
-}
-
-impl HelpOpts {
-    fn run(&self) {
-        if let Some(command) = self.free.first() {
-            if let Some(usage) = Commands::command_usage(command) {
-                println!("{}", usage);
-                exit(1);
-            }
-        }
-
-        println!("{}", Commands::usage());
-    }
-}
-
 /// Version options
-#[derive(Debug, Options)]
+#[derive(Debug, Parser)]
 pub struct VersionOpts {}
 
 impl VersionOpts {

cli/src/commands/readers.rs

@@ -1,7 +1,7 @@
 //! List detected readers
 
 use crate::terminal::STDOUT;
-use gumdrop::Options;
+use clap::Parser;
 use std::{
     io::{self, Write},
     process::exit,
@@ -10,7 +10,7 @@ use termcolor::{ColorSpec, StandardStreamLock, WriteColor};
 use yubikey::{Context, Serial};
 
 /// The `readers` subcommand
-#[derive(Debug, Options)]
+#[derive(Debug, Parser)]
 pub struct ReadersCmd {}
 
 impl ReadersCmd {

cli/src/commands/status.rs

@@ -1,7 +1,7 @@
 //! Print device status
 
 use crate::terminal::{print_cert_info, STDOUT};
-use gumdrop::Options;
+use clap::Parser;
 use std::io::{self, Write};
 use termcolor::{ColorSpec, StandardStreamLock, WriteColor};
 use yubikey::{piv::*, YubiKey};
@@ -10,7 +10,7 @@ use yubikey::{piv::*, YubiKey};
 const NONE_STR: &str = "<none>";
 
 /// The `status` subcommand
-#[derive(Debug, Options)]
+#[derive(Debug, Parser)]
 pub struct StatusCmd {}
 
 impl StatusCmd {