diff --git a/src/input.h b/src/input.h
index 182c38b89d..a50f769561 100644
--- a/src/input.h
+++ b/src/input.h
@@ -24,6 +24,7 @@ class Input : protected Pointers {
   friend class Info;
   friend class Error;
   friend class Deprecated;
+  friend class SimpleCommandsTest_Echo_Test;
 
  public:
   int narg;                    // # of command args
diff --git a/unittest/CMakeLists.txt b/unittest/CMakeLists.txt
index 99b5463a81..ab8c771dc8 100644
--- a/unittest/CMakeLists.txt
+++ b/unittest/CMakeLists.txt
@@ -1,10 +1,9 @@
 include(GTest)
 
 add_subdirectory(force-styles)
-
 add_subdirectory(utils)
-
 add_subdirectory(formats)
+add_subdirectory(commands)
 
 find_package(ClangFormat 8.0)
 
diff --git a/unittest/commands/CMakeLists.txt b/unittest/commands/CMakeLists.txt
new file mode 100644
index 0000000000..472337f1bc
--- /dev/null
+++ b/unittest/commands/CMakeLists.txt
@@ -0,0 +1,4 @@
+
+add_executable(test_simple_commands test_simple_commands.cpp)
+target_link_libraries(test_simple_commands PRIVATE lammps GTest::GMock GTest::GTest)
+add_test(NAME TestSimpleCommands COMMAND test_simple_commands WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR})
diff --git a/unittest/commands/test_simple_commands.cpp b/unittest/commands/test_simple_commands.cpp
new file mode 100644
index 0000000000..196a4506b1
--- /dev/null
+++ b/unittest/commands/test_simple_commands.cpp
@@ -0,0 +1,132 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+#include "input.h"
+#include "lammps.h"
+#include "utils.h"
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+
+#include <cstdio>
+#include <cstring>
+#include <fstream>
+#include <iostream>
+#include <mpi.h>
+
+// whether to print verbose output (i.e. not capturing LAMMPS screen output).
+bool verbose = false;
+
+namespace LAMMPS_NS {
+using ::testing::Eq;
+
+class SimpleCommandsTest : public ::testing::Test {
+protected:
+    LAMMPS *lmp;
+
+    void SetUp() override
+    {
+        const char *args[] = {"SimpleCommandsTest", "-log", "none", "-echo", "screen", "-nocite"};
+        char **argv        = (char **)args;
+        int argc           = sizeof(args) / sizeof(char *);
+        if (!verbose) ::testing::internal::CaptureStdout();
+        lmp = new LAMMPS(argc, argv, MPI_COMM_WORLD);
+        if (!verbose) ::testing::internal::GetCapturedStdout();
+    }
+
+    void TearDown() override
+    {
+        if (!verbose) ::testing::internal::CaptureStdout();
+        delete lmp;
+        if (!verbose) ::testing::internal::GetCapturedStdout();
+    }
+};
+
+TEST_F(SimpleCommandsTest, Echo)
+{
+    ASSERT_EQ(lmp->input->echo_screen, 1);
+    ASSERT_EQ(lmp->input->echo_log, 0);
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("echo none");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ASSERT_EQ(lmp->input->echo_screen, 0);
+    ASSERT_EQ(lmp->input->echo_log, 0);
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("echo both");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ASSERT_EQ(lmp->input->echo_screen, 1);
+    ASSERT_EQ(lmp->input->echo_log, 1);
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("echo screen");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ASSERT_EQ(lmp->input->echo_screen, 1);
+    ASSERT_EQ(lmp->input->echo_log, 0);
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("echo log");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ASSERT_EQ(lmp->input->echo_screen, 0);
+    ASSERT_EQ(lmp->input->echo_log, 1);
+}
+
+TEST_F(SimpleCommandsTest, Log)
+{
+    ASSERT_EQ(lmp->logfile, nullptr);
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("log simple_command_test.log");
+    lmp->input->one("print 'test1'");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ASSERT_NE(lmp->logfile, nullptr);
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("log none");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ASSERT_EQ(lmp->logfile, nullptr);
+
+    std::string text;
+    std::ifstream in;
+    in.open("simple_command_test.log");
+    in >> text;
+    in.close();
+    ASSERT_THAT(text, Eq("test1"));
+
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("log simple_command_test.log append");
+    lmp->input->one("print 'test2'");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ASSERT_NE(lmp->logfile, nullptr);
+    if (!verbose) ::testing::internal::CaptureStdout();
+    lmp->input->one("log none");
+    if (!verbose) ::testing::internal::GetCapturedStdout();
+    ASSERT_EQ(lmp->logfile, nullptr);
+
+    in.open("simple_command_test.log");
+    in >> text;
+    ASSERT_THAT(text, Eq("test1"));
+    in >> text;
+    ASSERT_THAT(text, Eq("test2"));
+    in.close();
+    remove("simple_command_test.log");
+}
+} // namespace LAMMPS_NS
+
+int main(int argc, char **argv)
+{
+    MPI_Init(&argc, &argv);
+    ::testing::InitGoogleMock(&argc, argv);
+    if ((argc > 1) && (strcmp(argv[1], "-v") == 0)) verbose = true;
+    return RUN_ALL_TESTS();
+}