touch: change message when directory

src/uu/touch/src/touch.rs

@@ -15,6 +15,7 @@ use clap::{crate_version, Arg, ArgAction, ArgGroup, ArgMatches, Command};
 use filetime::{set_file_times, set_symlink_file_times, FileTime};
 use std::ffi::OsString;
 use std::fs::{self, File};
+use std::io::{Error, ErrorKind};
 use std::path::{Path, PathBuf};
 use uucore::display::Quotable;
 use uucore::error::{FromIo, UResult, USimpleError};
@@ -126,7 +127,23 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
             }
 
             if let Err(e) = File::create(path) {
-                show!(e.map_err_context(|| format!("cannot touch {}", path.quote())));
+                // we need to check if the path is the path to a directory (ends with a separator)
+                // we can't use File::create to create a directory
+                // we cannot use path.is_dir() because it calls fs::metadata which we already called
+                // when stable, we can change to use e.kind() == std::io::ErrorKind::IsADirectory
+                let is_directory = if let Some(last_char) = path.to_string_lossy().chars().last() {
+                    last_char == std::path::MAIN_SEPARATOR
+                } else {
+                    false
+                };
+                if is_directory {
+                    let custom_err = Error::new(ErrorKind::Other, "No such file or directory");
+                    return Err(
+                        custom_err.map_err_context(|| format!("cannot touch {}", filename.quote()))
+                    );
+                } else {
+                    show!(e.map_err_context(|| format!("cannot touch {}", path.quote())));
+                }
                 continue;
             };
 

tests/by-util/test_touch.rs

@@ -689,10 +689,23 @@ fn test_touch_system_fails() {
 }
 
 #[test]
+#[cfg(not(target_os = "windows"))]
 fn test_touch_trailing_slash() {
     let (_at, mut ucmd) = at_and_ucmd!();
     let file = "no-file/";
-    ucmd.args(&[file]).fails();
+    ucmd.args(&[file]).fails().stderr_only(format!(
+        "touch: cannot touch '{file}': No such file or directory\n"
+    ));
+}
+
+#[test]
+#[cfg(target_os = "windows")]
+fn test_touch_trailing_slash_windows() {
+    let (_at, mut ucmd) = at_and_ucmd!();
+    let file = "no-file/";
+    ucmd.args(&[file]).fails().stderr_only(format!(
+        "touch: cannot touch '{file}': The filename, directory name, or volume label syntax is incorrect.\n"
+    ));
 }
 
 #[test]