Merge pull request #218 from dtolnay/shlex

Improve quoting of printed command

Cargo.lock

@@ -187,6 +187,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "serde",
+ "shlex",
  "syn",
  "syn-select",
  "tempfile",
@@ -708,6 +709,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "24188a676b6ae68c3b2cb3a01be17fbf7240ce009799bb56d5b1409051e78fde"
 
+[[package]]
+name = "shlex"
+version = "1.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0fda2ff0d084019ba4d7c6f371c95d8fd75ce3524c3cb8fb653a3023f6323e64"
+
 [[package]]
 name = "std_prelude"
 version = "0.2.12"

Cargo.toml

@@ -25,6 +25,7 @@ prettyplease = { version = "0.2.17", features = ["verbatim"] }
 proc-macro2 = "1.0.74"
 quote = { version = "1.0.35", default-features = false }
 serde = { version = "1.0.183", features = ["derive"] }
+shlex = "1.3"
 syn = { version = "2.0.46", default-features = false, features = ["clone-impls", "fold", "full", "parsing", "printing", "visit-mut"] }
 syn-select = "0.3"
 tempfile = "3.0"

src/cmd.rs

@@ -1,18 +1,13 @@
 use std::ffi::{OsStr, OsString};
-use std::fmt::{self, Display};
 
 #[derive(Clone)]
-pub struct Line {
-    bin: OsString,
+pub struct CommandArgs {
     args: Vec<OsString>,
 }
 
-impl Line {
-    pub fn new<S: AsRef<OsStr>>(bin: S) -> Self {
-        Line {
-            bin: bin.as_ref().to_owned(),
-            args: Vec::new(),
-        }
+impl CommandArgs {
+    pub fn new() -> Self {
+        CommandArgs { args: Vec::new() }
     }
 
     pub fn arg<S: AsRef<OsStr>>(&mut self, arg: S) {
@@ -33,17 +28,7 @@ impl Line {
     }
 }
 
-impl Display for Line {
-    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        write!(formatter, "{}", self.bin.to_string_lossy())?;
-        for arg in &self.args {
-            write!(formatter, " {}", arg.to_string_lossy())?;
-        }
-        Ok(())
-    }
-}
-
-impl IntoIterator for Line {
+impl IntoIterator for CommandArgs {
     type Item = OsString;
     type IntoIter = <Vec<OsString> as IntoIterator>::IntoIter;
 

src/error.rs

@@ -7,6 +7,7 @@ pub enum Error {
     Io(io::Error),
     TomlSer(toml::ser::Error),
     TomlDe(toml::de::Error),
+    Quote(shlex::QuoteError),
 }
 
 pub type Result<T> = std::result::Result<T, Error>;
@@ -29,12 +30,19 @@ impl From<toml::de::Error> for Error {
     }
 }
 
+impl From<shlex::QuoteError> for Error {
+    fn from(error: shlex::QuoteError) -> Self {
+        Error::Quote(error)
+    }
+}
+
 impl Display for Error {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
         match self {
             Error::Io(e) => e.fmt(formatter),
             Error::TomlSer(e) => e.fmt(formatter),
             Error::TomlDe(e) => e.fmt(formatter),
+            Error::Quote(e) => e.fmt(formatter),
         }
     }
 }
@@ -45,6 +53,7 @@ impl StdError for Error {
             Error::Io(e) => e.source(),
             Error::TomlSer(e) => e.source(),
             Error::TomlDe(e) => e.source(),
+            Error::Quote(e) => e.source(),
         }
     }
 }

src/main.rs

@@ -26,7 +26,7 @@ mod opts;
 mod unparse;
 mod version;
 
-use crate::cmd::Line;
+use crate::cmd::CommandArgs;
 use crate::config::Config;
 use crate::error::Result;
 use crate::opts::{Coloring, Expand, Subcommand};
@@ -35,6 +35,7 @@ use crate::version::Version;
 use bat::{PagingMode, PrettyPrinter};
 use clap::{CommandFactory as _, Parser, ValueEnum};
 use quote::quote;
+use std::borrow::Cow;
 use std::env;
 use std::error::Error as StdError;
 use std::ffi::{OsStr, OsString};
@@ -169,7 +170,7 @@ fn do_cargo_expand() -> Result<i32> {
 
     // Run cargo
     let mut cmd = Command::new(cargo_binary());
-    apply_args(&mut cmd, &args, &color, &outfile_path);
+    apply_args(&mut cmd, &args, &color, &outfile_path)?;
 
     if needs_rustc_bootstrap() {
         if let Ok(current_exe) = env::current_exe() {
@@ -318,9 +319,8 @@ fn which_rustfmt() -> Option<PathBuf> {
     }
 }
 
-fn apply_args(cmd: &mut Command, args: &Expand, color: &Coloring, outfile: &Path) {
-    let mut line = Line::new("cargo");
-
+fn apply_args(cmd: &mut Command, args: &Expand, color: &Coloring, outfile: &Path) -> Result<()> {
+    let mut line = CommandArgs::new();
     line.arg("rustc");
 
     if args.verbose {
@@ -462,10 +462,11 @@ fn apply_args(cmd: &mut Command, args: &Expand, color: &Coloring, outfile: &Path
     if args.verbose {
         let mut display = line.clone();
         display.insert(0, "+nightly");
-        print_command(display, color);
+        print_command(display, color)?;
     }
 
     cmd.args(line);
+    Ok(())
 }
 
 fn needs_rustc_bootstrap() -> bool {
@@ -514,7 +515,21 @@ fn needs_rustc_bootstrap() -> bool {
     !status.success()
 }
 
-fn print_command(line: Line, color: &Coloring) {
+fn print_command(args: CommandArgs, color: &Coloring) -> Result<()> {
+    let cmd: Vec<Cow<OsStr>> = iter::once(Cow::Borrowed(OsStr::new("cargo")))
+        .chain(args.into_iter().map(Cow::Owned))
+        .collect();
+
+    let cmd_lossy: Vec<Cow<str>> = cmd
+        .iter()
+        .map(Cow::as_ref)
+        .map(OsStr::to_string_lossy)
+        .collect();
+
+    let shell_words = shlex::Quoter::new()
+        .allow_nul(true)
+        .join(cmd_lossy.iter().map(Cow::as_ref))?;
+
     let color_choice = match color {
         Coloring::Auto => ColorChoice::Auto,
         Coloring::Always => ColorChoice::Always,
@@ -525,7 +540,8 @@ fn print_command(line: Line, color: &Coloring) {
     let _ = stream.set_color(ColorSpec::new().set_bold(true).set_fg(Some(Green)));
     let _ = write!(stream, "{:>12}", "Running");
     let _ = stream.reset();
-    let _ = writeln!(stream, " `{}`", line);
+    let _ = writeln!(stream, " `{}`", shell_words);
+    Ok(())
 }
 
 fn filter_err(cmd: &mut Command) -> io::Result<i32> {