Address review comments

src/error.rs

@@ -49,6 +49,6 @@ pub enum OptionsError<'a> {
     EmptyShell,
     #[error("Failed to parse '--shell <command>' expression as command line: {0}")]
     ShellParseError(shell_words::ParseError),
-    #[error("Unknown output policy '{0}'. Use ./{0} to output to a file named {0}.")]
+    #[error("Unknown output policy '{0}'. Use './{0}' to output to a file named '{0}'.")]
     UnknownOutputPolicy(String),
 }

src/options.rs

@@ -113,8 +113,8 @@ impl Default for RunBounds {
 /// How to handle the output of benchmarked commands
 #[derive(Debug, Clone, PartialEq)]
 pub enum CommandOutputPolicy {
-    /// Discard all output
-    Discard,
+    /// Redirect output to the null device
+    Null,
 
     /// Feed output through a pipe before discarding it
     Pipe,
@@ -123,19 +123,19 @@ pub enum CommandOutputPolicy {
     File(PathBuf),
 
     /// Show command output on the terminal
-    Forward,
+    Inherit,
 }
 
 impl Default for CommandOutputPolicy {
     fn default() -> Self {
-        CommandOutputPolicy::Discard
+        CommandOutputPolicy::Null
     }
 }
 
 impl CommandOutputPolicy {
     pub fn get_stdout_stderr(&self) -> io::Result<(Stdio, Stdio)> {
         let streams = match self {
-            CommandOutputPolicy::Discard => (Stdio::null(), Stdio::null()),
+            CommandOutputPolicy::Null => (Stdio::null(), Stdio::null()),
 
             // Typically only stdout is performance-relevant, so just pipe that
             CommandOutputPolicy::Pipe => (Stdio::piped(), Stdio::null()),
@@ -145,7 +145,7 @@ impl CommandOutputPolicy {
                 (file.into(), Stdio::null())
             }
 
-            CommandOutputPolicy::Forward => (Stdio::inherit(), Stdio::inherit()),
+            CommandOutputPolicy::Inherit => (Stdio::inherit(), Stdio::inherit()),
         };
 
         Ok(streams)
@@ -212,7 +212,7 @@ impl Default for Options {
             cleanup_command: None,
             output_style: OutputStyleOption::Full,
             executor_kind: ExecutorKind::default(),
-            command_output_policy: CommandOutputPolicy::Discard,
+            command_output_policy: CommandOutputPolicy::Null,
             time_unit: None,
         }
     }
@@ -269,12 +269,12 @@ impl Options {
         options.cleanup_command = matches.value_of("cleanup").map(String::from);
 
         options.command_output_policy = if matches.is_present("show-output") {
-            CommandOutputPolicy::Forward
+            CommandOutputPolicy::Inherit
         } else if let Some(output) = matches.value_of("output") {
             match output {
-                "null" => CommandOutputPolicy::Discard,
+                "null" => CommandOutputPolicy::Null,
                 "pipe" => CommandOutputPolicy::Pipe,
-                "inherit" => CommandOutputPolicy::Forward,
+                "inherit" => CommandOutputPolicy::Inherit,
                 arg => {
                     let path = PathBuf::from(arg);
                     if path.components().count() <= 1 {
@@ -284,7 +284,7 @@ impl Options {
                 }
             }
         } else {
-            CommandOutputPolicy::Discard
+            CommandOutputPolicy::Null
         };
 
         options.output_style = match matches.value_of("style") {
@@ -294,12 +294,12 @@ impl Options {
             Some("color") => OutputStyleOption::Color,
             Some("none") => OutputStyleOption::Disabled,
             _ => {
-                if options.command_output_policy != CommandOutputPolicy::Forward
-                    && atty::is(Stream::Stdout)
+                if options.command_output_policy == CommandOutputPolicy::Inherit
+                    || !atty::is(Stream::Stdout)
                 {
-                    OutputStyleOption::Full
-                } else {
                     OutputStyleOption::Basic
+                } else {
+                    OutputStyleOption::Full
                 }
             }
         };

src/timer/mod.rs

@@ -13,12 +13,10 @@ use std::fs::File;
 #[cfg(target_os = "linux")]
 use std::os::unix::io::AsRawFd;
 
-#[cfg(not(target_os = "linux"))]
-use std::io::Read;
-
 use crate::util::units::Second;
 use wall_clock_timer::WallClockTimer;
 
+use std::io::Read;
 use std::process::{ChildStdout, Command, ExitStatus};
 
 use anyhow::Result;
@@ -65,14 +63,11 @@ fn discard(output: ChildStdout) {
         }
     }
 
-    #[cfg(not(target_os = "linux"))]
-    {
-        let mut output = output;
-        let mut buf = [0; CHUNK_SIZE];
-        while let Ok(bytes) = output.read(&mut buf) {
-            if bytes == 0 {
-                break;
-            }
+    let mut output = output;
+    let mut buf = [0; CHUNK_SIZE];
+    while let Ok(bytes) = output.read(&mut buf) {
+        if bytes == 0 {
+            break;
         }
     }
 }
@@ -81,17 +76,19 @@ fn discard(output: ChildStdout) {
 pub fn execute_and_measure(mut command: Command) -> Result<TimerResult> {
     let wallclock_timer = WallClockTimer::start();
 
-    let mut child = command.spawn()?;
-    let output = child.stdout.take();
-
     #[cfg(not(windows))]
     let cpu_timer = self::unix_timer::CPUTimer::start();
+
+    let mut child = command.spawn()?;
+
     #[cfg(windows)]
     let cpu_timer = self::windows_timer::CPUTimer::start_for_process(&child);
 
-    if let Some(output) = output {
+    if let Some(output) = child.stdout.take() {
+        // Handle CommandOutputPolicy::Pipe
         discard(output);
     }
+
     let status = child.wait()?;
 
     let (time_user, time_system) = cpu_timer.stop();