hashsum: fix help text to show actual utility name

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

@@ -1,6 +1,9 @@
 hashsum-about = Compute and check message digests.
 hashsum-usage = hashsum --<digest> [OPTIONS]... [FILE]...
 
+# Utility-specific usage template
+hashsum-usage-specific = {$utility_name} [OPTION]... [FILE]...
+
 # Help messages
 hashsum-help-binary-windows = read or check in binary mode (default)
 hashsum-help-binary-other = read in binary mode

src/uu/hashsum/src/hashsum.rs

@@ -498,7 +498,7 @@ pub fn uu_app_custom() -> Command {
 /// hashsum is handled differently in build.rs
 /// therefore, this is different from other utilities.
 fn uu_app(binary_name: &str) -> (Command, bool) {
-    match binary_name {
+    let (mut command, is_hashsum_bin) = match binary_name {
         // These all support the same options.
         "md5sum" | "sha1sum" | "sha224sum" | "sha256sum" | "sha384sum" | "sha512sum" => {
             (uu_app_common(), false)
@@ -516,7 +516,17 @@ fn uu_app(binary_name: &str) -> (Command, bool) {
         "b3sum" => (uu_app_b3sum(), false),
         // We're probably just being called as `hashsum`, so give them everything.
         _ => (uu_app_custom(), true),
+    };
+
+    // If not called as generic hashsum, override the command name and usage
+    if !is_hashsum_bin {
+        let usage = translate!("hashsum-usage-specific", "utility_name" => binary_name);
+        command = command
+            .help_template(uucore::localized_help_template(binary_name))
+            .override_usage(format_usage(&usage));
     }
+
+    (command, is_hashsum_bin)
 }
 
 #[allow(clippy::cognitive_complexity)]

tests/by-util/test_hashsum.rs

@@ -1080,3 +1080,48 @@ fn test_check_sha256_binary() {
         .no_stderr()
         .stdout_is("binary.png: OK\n");
 }
+
+#[test]
+fn test_help_shows_correct_utility_name() {
+    // Test that help output shows the actual utility name instead of "hashsum"
+    let scene = TestScenario::new(util_name!());
+
+    // Test md5sum
+    scene
+        .ccmd("md5sum")
+        .arg("--help")
+        .succeeds()
+        .stdout_contains("Usage: md5sum")
+        .stdout_does_not_contain("Usage: hashsum");
+
+    // Test sha256sum
+    scene
+        .ccmd("sha256sum")
+        .arg("--help")
+        .succeeds()
+        .stdout_contains("Usage: sha256sum")
+        .stdout_does_not_contain("Usage: hashsum");
+
+    // Test b2sum
+    scene
+        .ccmd("b2sum")
+        .arg("--help")
+        .succeeds()
+        .stdout_contains("Usage: b2sum")
+        .stdout_does_not_contain("Usage: hashsum");
+
+    // Test b3sum
+    scene
+        .ccmd("b3sum")
+        .arg("--help")
+        .succeeds()
+        .stdout_contains("Usage: b3sum")
+        .stdout_does_not_contain("Usage: hashsum");
+
+    // Test that generic hashsum still shows the correct usage
+    scene
+        .ccmd("hashsum")
+        .arg("--help")
+        .succeeds()
+        .stdout_contains("Usage: hashsum --<digest>");
+}