find: name the program as invoked in every message

src/find/main.rs

@@ -25,7 +25,8 @@ fn main() {
         Ok(args) => args,
         Err(invalid) => {
             eprintln!(
-                "find: invalid (non-UTF-8) argument: {}",
+                "{}: invalid (non-UTF-8) argument: {}",
+                findutils::find::program_name(),
                 invalid.to_string_lossy()
             );
             std::process::exit(1);

src/find/matchers/printf.rs

@@ -205,7 +205,10 @@ impl FormatStringParser<'_> {
                 '0' => "\0",
                 '\\' => "\\",
                 c => {
-                    eprintln!("find: warning: unrecognized escape '\\{c}'");
+                    eprintln!(
+                        "{}: warning: unrecognized escape '\\{c}'",
+                        crate::find::program_name()
+                    );
                     return Ok(FormatComponent::Literal(format!("\\{c}")));
                 }
             };
@@ -317,7 +320,10 @@ impl FormatStringParser<'_> {
             'Y' => FormatDirective::Type { follow_links: true },
             // TODO: %Z
             _ => {
-                eprintln!("find: warning: unrecognized format directive '%{first}'");
+                eprintln!(
+                    "{}: warning: unrecognized format directive '%{first}'",
+                    crate::find::program_name()
+                );
                 return Ok(FormatComponent::Literal(format!("%{first}")));
             }
         };
@@ -650,9 +656,14 @@ impl Printf {
         }
 
         if let Some((_, path)) = &self.output_file {
-            let _ = writeln!(&mut stderr(), "find: {}: {error}", path.display());
+            let _ = writeln!(
+                &mut stderr(),
+                "{}: {}: {error}",
+                crate::find::program_name(),
+                path.display()
+            );
         } else {
-            let _ = writeln!(&mut stderr(), "find: {error}");
+            let _ = writeln!(&mut stderr(), "{}: {error}", crate::find::program_name());
         }
         matcher_io.set_exit_code(1);
     }

src/find/mod.rs

@@ -194,7 +194,7 @@ impl Iterator for Files0Paths {
             }
             if buffer.is_empty() {
                 // Skip it so as to avoid a file not found error.
-                eprintln!("find: invalid zero-length file name");
+                eprintln!("{}: invalid zero-length file name", program_name());
                 continue;
             }
             return Some(String::from_utf8(buffer).map_err(Into::into));
@@ -492,6 +492,23 @@ fn print_version(deps: &dyn Dependencies) -> Result<(), io::Error> {
     )
 }
 
+/// The name `find` was invoked as, for prefixing its messages: the base name
+/// of argv[0], without the `.exe` that Windows executables carry.
+pub fn program_name() -> &'static str {
+    let name = uucore::util_name();
+    let path = std::path::Path::new(name);
+    if cfg!(windows)
+        && path
+            .extension()
+            .is_some_and(|ext| ext.eq_ignore_ascii_case("exe"))
+    {
+        if let Some(stem) = path.file_stem().and_then(std::ffi::OsStr::to_str) {
+            return stem;
+        }
+    }
+    name
+}
+
 /// Does all the work for find.
 ///
 /// All main has to do is pass in the command-line args and exit the process
@@ -501,7 +518,7 @@ pub fn find_main(args: &[&str], deps: &dyn Dependencies) -> i32 {
     match do_find(&args[1..], deps) {
         Ok(ret) => ret,
         Err(e) => {
-            writeln!(&mut stderr(), "find: {e}").unwrap();
+            writeln!(&mut stderr(), "{}: {e}", program_name()).unwrap();
             1
         }
     }