printenv: Add test for printenv.

Reviewed by:	asomers
Differential Revision: https://reviews.freebsd.org/D41468

etc/mtree/BSD.tests.dist

@@ -1095,6 +1095,8 @@
         ..
         pr
         ..
+        printenv
+        ..
         printf
         ..
         procstat

usr.bin/printenv/Makefile

@@ -1,5 +1,10 @@
 #	@(#)Makefile	8.1 (Berkeley) 6/6/93
 
+.include <src.opts.mk>
+
 PROG=	printenv
 
-.include <bsd.prog.mk>
+HAS_TESTS=
+SUBDIR.${MK_TESTS}+= tests
+
+.include <bsd.prog.mk>

usr.bin/printenv/tests/Makefile

@@ -0,0 +1,6 @@
+PACKAGE=	tests
+
+ATF_TESTS_SH=	printenv_test
+BINDIR=		${TESTSDIR}
+
+.include <bsd.test.mk>

usr.bin/printenv/tests/printenv_test.sh

@@ -0,0 +1,64 @@
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2023 The FreeBSD Foundation
+#
+# This software was developed1 by Yan-Hao Wang <bses30074@gmail.com>
+# under sponsorship from the FreeBSD Foundation.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE
+#
+
+atf_test_case base
+base_head()
+{
+    atf_set "descr" "Check that all reported variables exist with the reported values."
+}
+base_body()
+{
+    printenv | while IFS= read -r env; do
+            env_name=${env%%=*}
+            env_value=${env#*=}
+            expected_value=$(eval echo "\$$env_name")
+            atf_check_equal "${env_value}" "${expected_value}"
+    done
+}
+
+atf_test_case add_delete_env
+add_delete_env_head()
+{
+    atf_set "descr" "New changes to the environment should be reflected in printenv's output"
+}
+add_delete_env_body()
+{
+    env_name=$(date +"%Y%m%d%H%M%S")
+    export "env_${env_name}=value"
+    atf_check -o inline:"value\n" printenv "env_${env_name}"
+    unset "env_${env_name}"
+    atf_check -s exit:1 printenv "env_${env_name}"
+}
+
+atf_init_test_cases()
+{
+    atf_add_test_case base
+    atf_add_test_case add_delete_env
+}