stdbuf: move from getopts to clap

tests/by-util/test_stdbuf.rs

@@ -1,13 +1,71 @@
+#[cfg(not(target_os = "windows"))]
 use crate::common::util::*;
 
+#[cfg(not(target_os = "windows"))]
 #[test]
 fn test_stdbuf_unbuffered_stdout() {
-    if cfg!(target_os = "linux") {
-        // This is a basic smoke test
-        new_ucmd!()
-            .args(&["-o0", "head"])
-            .pipe_in("The quick brown fox jumps over the lazy dog.")
-            .run()
-            .stdout_is("The quick brown fox jumps over the lazy dog.");
-    }
+    // This is a basic smoke test
+    new_ucmd!()
+        .args(&["-o0", "head"])
+        .pipe_in("The quick brown fox jumps over the lazy dog.")
+        .run()
+        .stdout_is("The quick brown fox jumps over the lazy dog.");
+}
+
+#[cfg(not(target_os = "windows"))]
+#[test]
+fn test_stdbuf_line_buffered_stdout() {
+    new_ucmd!()
+        .args(&["-oL", "head"])
+        .pipe_in("The quick brown fox jumps over the lazy dog.")
+        .run()
+        .stdout_is("The quick brown fox jumps over the lazy dog.");
+}
+
+#[cfg(not(target_os = "windows"))]
+#[test]
+fn test_stdbuf_no_buffer_option_fails() {
+    new_ucmd!()
+        .args(&["head"])
+        .pipe_in("The quick brown fox jumps over the lazy dog.")
+        .fails()
+        .stderr_is(
+            "error: The following required arguments were not provided:\n    \
+            --error <MODE>\n    \
+            --input <MODE>\n    \
+            --output <MODE>\n\n\
+            USAGE:\n    \
+            stdbuf OPTION... COMMAND\n\n\
+            For more information try --help",
+        );
+}
+
+#[cfg(not(target_os = "windows"))]
+#[test]
+fn test_stdbuf_trailing_var_arg() {
+    new_ucmd!()
+        .args(&["-i", "1024", "tail", "-1"])
+        .pipe_in("The quick brown fox\njumps over the lazy dog.")
+        .run()
+        .stdout_is("jumps over the lazy dog.");
+}
+
+#[cfg(not(target_os = "windows"))]
+#[test]
+fn test_stdbuf_line_buffering_stdin_fails() {
+    new_ucmd!()
+        .args(&["-i", "L", "head"])
+        .pipe_in("The quick brown fox jumps over the lazy dog.")
+        .fails()
+        .stderr_is("stdbuf: error: line buffering stdin is meaningless\nTry 'stdbuf --help' for more information.");
+}
+
+#[cfg(not(target_os = "windows"))]
+#[test]
+fn test_stdbuf_invalid_mode_fails() {
+    new_ucmd!()
+        .args(&["-i", "1024R", "head"])
+        .pipe_in("The quick brown fox jumps over the lazy dog.")
+        .fails()
+        .stderr_is("stdbuf: error: invalid mode 1024R\nTry 'stdbuf --help' for more information.");
 }