rm: hint to use ./-foo when removing a dash-prefixed file

src/uu/rm/Cargo.toml

@@ -21,7 +21,7 @@ doctest = false
 [dependencies]
 thiserror = { workspace = true }
 clap = { workspace = true }
-uucore = { workspace = true, features = ["fs", "parser"] }
+uucore = { workspace = true, features = ["fs", "parser", "quoting-style"] }
 fluent = { workspace = true }
 indicatif = { workspace = true }
 

src/uu/rm/locales/en-US.ftl

@@ -36,6 +36,8 @@ rm-progress-removing = Removing
 # Error messages
 rm-error-missing-operand = missing operand
   Try '{$util_name} --help' for more information.
+rm-hint-dash-file = Try '{$util_name} ./{$path}' to remove the file {$file}.
+  Try '{$util_name} --help' for more information.
 rm-error-cannot-remove-no-such-file = cannot remove {$file}: No such file or directory
 rm-error-cannot-remove-permission-denied = cannot remove {$file}: Permission denied
 rm-error-cannot-remove-is-directory = cannot remove {$file}: Is a directory

src/uu/rm/locales/fr-FR.ftl

@@ -36,6 +36,8 @@ rm-progress-removing = Suppression
 # Messages d'erreur
 rm-error-missing-operand = opérande manquant
   Essayez '{$util_name} --help' pour plus d'informations.
+rm-hint-dash-file = Essayez '{$util_name} ./{$path}' pour supprimer le fichier {$file}.
+  Essayez '{$util_name} --help' pour plus d'informations.
 rm-error-cannot-remove-no-such-file = impossible de supprimer {$file} : Aucun fichier ou répertoire de ce type
 rm-error-cannot-remove-permission-denied = impossible de supprimer {$file} : Permission refusée
 rm-error-cannot-remove-is-directory = impossible de supprimer {$file} : C'est un répertoire

src/uu/rm/src/rm.rs

@@ -10,7 +10,7 @@ use clap::{Arg, ArgAction, Command, parser::ValueSource};
 use indicatif::{ProgressBar, ProgressStyle};
 use std::ffi::{OsStr, OsString};
 use std::fs::{self, Metadata};
-use std::io::{self, IsTerminal, stdin};
+use std::io::{self, IsTerminal, Write, stdin};
 use std::ops::BitOr;
 #[cfg(unix)]
 use std::os::unix::ffi::OsStrExt;
@@ -22,6 +22,7 @@ use thiserror::Error;
 use uucore::display::Quotable;
 use uucore::error::{FromIo, UError, UResult};
 use uucore::parser::shortcut_value_parser::ShortcutValueParser;
+use uucore::quoting_style::{QuotingStyle, locale_aware_escape_name};
 use uucore::translate;
 use uucore::{format_usage, os_str_as_bytes, prompt_yes, show_error};
 
@@ -203,7 +204,9 @@ static ARG_FILES: &str = "files";
 #[uucore::main]
 pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     let args: Vec<OsString> = args.collect();
-    let matches = uucore::clap_localization::handle_clap_result(uu_app(), args.iter())?;
+    let matches = uu_app()
+        .try_get_matches_from(args.iter())
+        .map_err(|e| handle_parse_error(e, &args))?;
 
     let files: Vec<_> = matches
         .get_many::<OsString>(ARG_FILES)
@@ -293,6 +296,38 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
     Ok(())
 }
 
+/// Turn a clap parsing error into a `UError`, reproducing GNU's hint when an
+/// unknown `-foo` option is actually the name of an existing file: it suggests
+/// `rm ./-foo` so the name is treated as a path. See `tests/rm/dash-hint.sh`.
+fn handle_parse_error(e: clap::Error, args: &[OsString]) -> Box<dyn UError> {
+    let dash_file = args.iter().skip(1).find(|a| {
+        os_str_as_bytes(a).is_ok_and(|b| b.len() >= 2 && b[0] == b'-')
+            && fs::symlink_metadata(a).is_ok()
+    });
+    if let (true, Some(file)) = (e.exit_code() != 0, dash_file) {
+        // The path is shell-escaped (quoted only if needed), the file name is
+        // always quoted, matching GNU's two quoting styles.
+        let path = locale_aware_escape_name(file, QuotingStyle::SHELL_ESCAPE);
+        let quoted = locale_aware_escape_name(file, QuotingStyle::SHELL_ESCAPE_QUOTE);
+        let _ = writeln!(
+            io::stderr(),
+            "{}",
+            translate!(
+                "rm-hint-dash-file",
+                "util_name" => uucore::execution_phrase(),
+                "path" => path.to_string_lossy(),
+                "file" => quoted.to_string_lossy()
+            )
+        );
+        return 1.into();
+    }
+    // Otherwise defer to the standard clap handling (incl. `--help`/`--version`).
+    match uucore::clap_localization::handle_clap_result(uu_app(), args.iter()) {
+        Ok(_) => 1.into(),
+        Err(e) => e,
+    }
+}
+
 pub fn uu_app() -> Command {
     Command::new("rm")
         .version(uucore::crate_version!())

tests/by-util/test_rm.rs

@@ -1581,3 +1581,37 @@ fn test_symlink_to_dot_protection() {
     assert!(at.file_exists("subdir/file"));
     assert!(at.file_exists("topfile"));
 }
+
+#[test]
+fn test_dash_hint() {
+    // `rm -foo` where a file named "-foo" exists: GNU suggests `rm ./-foo`.
+    // The invocation prefix (`{$util_name}`) varies in tests, so only the
+    // stable parts are checked.
+    let ts = TestScenario::new(util_name!());
+    let at = &ts.fixtures;
+
+    at.touch("-foo");
+    ts.ucmd()
+        .arg("-foo")
+        .fails_with_code(1)
+        .stderr_contains("./-foo' to remove the file '-foo'.")
+        .stderr_contains("--help' for more information.");
+    assert!(at.file_exists("-foo"));
+
+    // The suggestion is shell-escaped so it can be copy-pasted. Newlines are
+    // not valid in Windows file names, so only exercise this on Unix.
+    #[cfg(unix)]
+    {
+        at.touch("-foo\nbar");
+        ts.ucmd()
+            .arg("-foo\nbar")
+            .fails_with_code(1)
+            .stderr_contains("./'-foo'$'\\n''bar'' to remove the file '-foo'$'\\n''bar'.");
+    }
+
+    // No matching file exists: the hint must not be shown.
+    ts.ucmd()
+        .arg("-bar")
+        .fails_with_code(1)
+        .stderr_does_not_contain("to remove the file");
+}