fix(loop): escape argument errors

Cargo.toml

@@ -11,6 +11,8 @@ anyhow = "1.0"
 clap = { version = "4.3", features = ["derive"] }
 colored = "2.0"
 loop_lib = { path = "../loop_lib" }
+# Any 0.x, as for loop_lib
+meta_core = { path = "../meta_core", version = "<1" }
 rayon = "1.7"
 serde_json = "1.0"
 walkdir = "2.3"

src/main.rs

@@ -41,7 +41,7 @@ struct Cli {
 }
 
 fn main() -> Result<()> {
-    let cli = Cli::parse();
+    let cli = parse_cli();
 
     let config_path = cli.config.unwrap_or_else(|| PathBuf::from(".looprc"));
 
@@ -50,13 +50,19 @@ fn main() -> Result<()> {
         std::process::exit(0);
     }
 
-    // Parse the .meta file
+    // Parse the .looprc file
     let absolute_path = std::env::current_dir()?.join(&config_path);
 
     if cli.verbose {
         println!("{}", "Verbose mode enabled".green());
-        println!("\nResolved config file path: {}", absolute_path.display());
-        println!("Executing command: {}", display_command(&cli.command));
+        println!(
+            "\nResolved config file path: {}",
+            meta_core::display::escape_path(&absolute_path)
+        );
+        println!(
+            "Executing command: {}",
+            meta_core::display::escape(&display_command(&cli.command))
+        );
     }
 
     let mut config = if config_path.exists() {
@@ -87,3 +93,30 @@ fn main() -> Result<()> {
 
     Ok(())
 }
+
+/// Parse the command line. Clap quotes rejected values as given, so an error
+/// is shown from the escaped arguments: the same error, with values that
+/// can't move the cursor or forge a line.
+fn parse_cli() -> Cli {
+    use clap::error::ErrorKind;
+    Cli::try_parse().unwrap_or_else(|e| match e.kind() {
+        // clap's invalid UTF-8 error doesn't echo the value
+        ErrorKind::DisplayHelp
+        | ErrorKind::DisplayVersion
+        | ErrorKind::DisplayHelpOnMissingArgumentOrSubcommand
+        | ErrorKind::InvalidUtf8 => e.exit(),
+        _ => {
+            let shown = std::env::args_os()
+                .map(|arg| meta_core::display::escape(&arg.to_string_lossy()).into_owned());
+            match Cli::try_parse_from(shown) {
+                Err(shown) => shown.exit(),
+                Ok(_) => Cli::command()
+                    .error(
+                        ErrorKind::InvalidValue,
+                        "an argument contains a control character",
+                    )
+                    .exit(),
+            }
+        }
+    })
+}