yes: switch to clap and try to decrease allocs

Cargo.lock

@@ -1928,7 +1928,7 @@ dependencies = [
 name = "yes"
 version = "0.0.1"
 dependencies = [
- "getopts 0.2.17 (registry+https://github.com/rust-lang/crates.io-index)",
+ "clap 2.31.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "uucore 0.0.1",
 ]
 

src/yes/Cargo.toml

@@ -2,6 +2,7 @@
 name = "yes"
 version = "0.0.1"
 authors = []
+description = "Repeatedly output a line with all specified STRING(s), or 'y'."
 build = "../../mkmain.rs"
 
 [lib]
@@ -9,8 +10,11 @@ name = "uu_yes"
 path = "yes.rs"
 
 [dependencies]
-getopts = "0.2.14"
-uucore = { path="../uucore" }
+clap = "2.31"
+
+[dependencies.uucore]
+path = "../uucore"
+default-features = false
 
 [[bin]]
 name = "yes"

src/yes/yes.rs

@@ -11,54 +11,50 @@
 
 /* last synced with: yes (GNU coreutils) 8.13 */
 
-extern crate getopts;
-
+#[macro_use]
+extern crate clap;
 #[macro_use]
 extern crate uucore;
 
-use getopts::Options;
+use clap::Arg;
+use std::borrow::Cow;
+use std::io::{self, Write};
 
-static NAME: &'static str = "yes";
-static VERSION: &'static str = env!("CARGO_PKG_VERSION");
+// force a re-build whenever Cargo.toml changes
+const _CARGO_TOML: &'static str = include_str!("Cargo.toml");
 
 const BUF_SIZE: usize = 8192;
 
 pub fn uumain(args: Vec<String>) -> i32 {
-    let mut opts = Options::new();
+    let app = app_from_crate!().arg(Arg::with_name("STRING").index(1).multiple(true));
 
-    opts.optflag("h", "help", "display this help and exit");
-    opts.optflag("V", "version", "output version information and exit");
-
-    let matches = match opts.parse(&args[1..]) {
+    let matches = match app.get_matches_from_safe(args) {
         Ok(m) => m,
-        Err(f) => crash!(1, "invalid options\n{}", f),
-    };
-    if matches.opt_present("help") {
-        println!("{} {}", NAME, VERSION);
-        println!("");
-        println!("Usage:");
-        println!("  {0} [STRING]... [OPTION]...", NAME);
-        println!("");
-        print!(
-            "{}",
-            opts.usage("Repeatedly output a line with all specified STRING(s), or 'y'.")
-        );
-        return 0;
-    }
-    if matches.opt_present("version") {
-        println!("{} {}", NAME, VERSION);
-        return 0;
-    }
-    let string = if matches.free.is_empty() {
-        "y".to_owned()
-    } else {
-        matches.free.join(" ")
+        Err(ref e)
+            if e.kind == clap::ErrorKind::HelpDisplayed
+                || e.kind == clap::ErrorKind::VersionDisplayed =>
+        {
+            println!("{}", e);
+            return 0;
+        }
+        Err(f) => {
+            show_error!("{}", f);
+            return 1;
+        }
     };
 
-    let mut multistring = string.clone();
+    let string = if let Some(values) = matches.values_of("STRING") {
+        let mut result = values.fold(String::new(), |res, s| res + s + " ");
+        result.pop();
+        Cow::from(result)
+    } else {
+        Cow::from("y")
+    };
+
+    let mut multistring = String::with_capacity(BUF_SIZE);
     while multistring.len() < BUF_SIZE - string.len() - 1 {
-        multistring.push_str("\n");
         multistring.push_str(&string);
+        multistring.push_str("\n");
     }
 
     exec(&multistring[..]);
@@ -67,7 +63,9 @@ pub fn uumain(args: Vec<String>) -> i32 {
 }
 
 pub fn exec(string: &str) {
+    let stdout_raw = io::stdout();
+    let mut stdout = stdout_raw.lock();
     loop {
-        println!("{}", string)
+        writeln!(stdout, "{}", string).unwrap();
     }
 }