2 files changed, 47 insertions, 0 deletions

diff --git a/lib/libutil++/tests/Makefile b/lib/libutil++/tests/Makefile
index 81b7be4f5660..e7720d122f36 100644
--- a/lib/libutil++/tests/Makefile
+++ b/lib/libutil++/tests/Makefile
@@ -1,9 +1,12 @@
 PACKAGE=	tests
 
+ATF_TESTS_CXX+=	pidfile_test
 ATF_TESTS_CXX+=	stringf_test
 ATF_TESTS_CXX+=	up_test
 
 CFLAGS+=	-I${SRCTOP}/lib/libutil++
 LIBADD+=	util++
 
+LIBADD.pidfile_test+= util
+
 .include <bsd.test.mk>
diff --git a/lib/libutil++/tests/pidfile_test.cc b/lib/libutil++/tests/pidfile_test.cc
new file mode 100644
index 000000000000..067f10e8fab8
--- /dev/null
+++ b/lib/libutil++/tests/pidfile_test.cc
@@ -0,0 +1,44 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2025 Chelsio Communications, Inc.
+ * Written by: John Baldwin <jhb@FreeBSD.org>
+ */
+
+#include <atf-c++.hpp>
+#include <sys/stat.h>
+#include <libutil.h>
+
+#include <libutil++.hh>
+
+ATF_TEST_CASE_WITHOUT_HEAD(basic);
+ATF_TEST_CASE_BODY(basic)
+{
+	pid_t other;
+	struct pidfh *pfh = pidfile_open("test_pidfile", 0600, &other);
+	ATF_REQUIRE(pfh != nullptr);
+	ATF_REQUIRE(pidfile_fileno(pfh) >= 0);
+
+	struct stat sb;
+	ATF_REQUIRE(fstat(pidfile_fileno(pfh), &sb) == 0);
+	ATF_REQUIRE_EQ(0, sb.st_size);
+
+	freebsd::pidfile pf(pfh);
+	ATF_REQUIRE_EQ(pidfile_fileno(pfh), pf.fileno());
+
+	ATF_REQUIRE(pf.write() == 0);
+	
+	ATF_REQUIRE(fstat(pf.fileno(), &sb) == 0);
+	ATF_REQUIRE(sb.st_size > 0);
+
+	ATF_REQUIRE(pf.close() == 0);
+	ATF_REQUIRE(pf.fileno() == -1);
+	ATF_REQUIRE_EQ(EDOOFUS, errno);
+
+	ATF_REQUIRE(unlink("test_pidfile") == 0);
+}
+
+ATF_INIT_TEST_CASES(tcs)
+{
+	ATF_ADD_TEST_CASE(tcs, basic);
+}