diff --git a/modules/libcom/test/Makefile b/modules/libcom/test/Makefile
index f2e495a90..27577f012 100755
--- a/modules/libcom/test/Makefile
+++ b/modules/libcom/test/Makefile
@@ -241,6 +241,11 @@ TESTS += yajlTest
 endif
 endif
 
+TESTPROD_HOST += iocshTest
+iocshTest_SRCS += iocshTest.cpp
+TESTS += iocshTest
+TESTFILES += $(wildcard ../iocshTest*.cmd)
+
 # The testHarness runs all the test programs in a known working order.
 testHarness_SRCS += epicsRunLibComTests.c
 
@@ -300,3 +305,6 @@ endif
 endif
 
 include $(TOP)/configure/RULES
+
+rtemsTestData.c : $(TESTFILES) $(TOOLS)/epicsMakeMemFs.pl
+	$(PERL) $(TOOLS)/epicsMakeMemFs.pl $@ epicsRtemsFSImage $(TESTFILES)
diff --git a/modules/libcom/test/iocshTest.cpp b/modules/libcom/test/iocshTest.cpp
new file mode 100644
index 000000000..1216ed579
--- /dev/null
+++ b/modules/libcom/test/iocshTest.cpp
@@ -0,0 +1,131 @@
+/*************************************************************************\
+* Copyright (c) 2019 Michael Davidsaver
+* EPICS BASE is distributed subject to a Software License Agreement found
+* in file LICENSE that is included with this distribution.
+\*************************************************************************/
+
+#include <string>
+#include <fstream>
+#include <set>
+
+#include <osiUnistd.h>
+#include <osiFileName.h>
+#include <dbDefs.h>
+#include <iocsh.h>
+#include <libComRegister.h>
+
+#include <epicsUnitTest.h>
+#include <testMain.h>
+
+namespace {
+void findTestData()
+{
+    const char *locations[] = {
+        ".",
+        "..",
+        ".." OSI_PATH_LIST_SEPARATOR "O.Common",
+        "O.Common",
+    };
+
+    for(size_t i=0; i<NELEMENTS(locations); i++) {
+        std::string path(locations[i]);
+        path += OSI_PATH_SEPARATOR "iocshTestSuccess.cmd";
+
+        std::ifstream strm(path.c_str());
+        if(strm.good()) {
+            testDiag("Found test data in %s", locations[i]);
+            if(chdir(locations[i])!=0)
+                testAbort("Unable to cd \"%s\"", locations[i]);
+            return;
+        }
+    }
+
+    testAbort("Failed to find test data");
+}
+
+void testFile(const char *fname, bool expect=true)
+{
+    testDiag("run \"%s\"", fname);
+    int err = iocsh(fname);
+    testOk((err==0) ^ (!expect), "%s \"%s\" -> %d", expect ? "ran" : "expected error from", fname, err);
+}
+
+void testCmd(const char *cmd, bool expect=true)
+{
+    testDiag("eval \"%s\"", cmd);
+    int err = iocshCmd(cmd);
+    testOk((err==0) ^ (!expect), "%s \"%s\" -> %d", expect ? "eval'd" : "expected error from", cmd, err);
+}
+
+std::set<std::string> reached;
+const iocshArg positionArg0 = {"position", iocshArgString};
+const iocshArg * const positionArgs[1] = { &positionArg0 };
+const iocshFuncDef positionFuncDef = {"position",1,positionArgs};
+void positionCallFunc(const iocshArgBuf *args)
+{
+    testDiag("Reaching \"%s\"", args[0].sval);
+    reached.insert(args[0].sval);
+}
+
+void testPosition(const std::string& pos, bool expect=true)
+{
+    testOk((reached.find(pos)!=reached.end()) ^ !expect,
+           "%sreached position %s", expect ? "" : "not ", pos.c_str());
+}
+
+const iocshArg assertArg0 = {"condition", iocshArgInt};
+const iocshArg * const assertArgs[1] = {&assertArg0};
+const iocshFuncDef assertFuncDef = {"assert",1,assertArgs};
+void assertCallFunc(const iocshArgBuf *args)
+{
+    iocshSetError(args[0].ival);
+}
+
+} // namespace
+
+MAIN(iocshTest)
+{
+    testPlan(19);
+    libComRegister();
+    iocshRegister(&positionFuncDef, &positionCallFunc);
+    iocshRegister(&assertFuncDef, &assertCallFunc);
+    findTestData();
+
+    testFile("iocshTestSuccess.cmd");
+    testPosition("success");
+    reached.clear();
+    testPosition("success", false);
+
+    testCmd("<iocshTestSuccess.cmd");
+    testPosition("success");
+    reached.clear();
+
+    testCmd("no_such_command", false);
+    testFile("no_such_file.cmd", false);
+    testCmd("<no_such_file.cmd", false);
+
+    testCmd("assert 0");
+    testCmd("assert 1", false);
+
+    testDiag("Check argument parsing errors");
+
+    // iocshArgDouble
+    testCmd("epicsThreadSleep foo", false);
+    // iocshArgInt
+    testCmd("epicsMutexShowAll foo", false);
+
+    testDiag("successful indirection");
+
+    testFile("iocshTestSuccessIndirect.cmd");
+    testPosition("success");
+    testPosition("after_success");
+    reached.clear();
+
+    testFile("iocshTestBadArgIndirect.cmd", false);
+    testPosition("before_error");
+    testPosition("after_error", false);
+    testPosition("after_error_1", false);
+    reached.clear();
+
+    return testDone();
+}
diff --git a/modules/libcom/test/iocshTestBadArg.cmd b/modules/libcom/test/iocshTestBadArg.cmd
new file mode 100644
index 000000000..30bbf3922
--- /dev/null
+++ b/modules/libcom/test/iocshTestBadArg.cmd
@@ -0,0 +1,4 @@
+on error break
+position before_error
+epicsThreadSleep bad
+position after_error
diff --git a/modules/libcom/test/iocshTestBadArgIndirect.cmd b/modules/libcom/test/iocshTestBadArgIndirect.cmd
new file mode 100644
index 000000000..ec498d2be
--- /dev/null
+++ b/modules/libcom/test/iocshTestBadArgIndirect.cmd
@@ -0,0 +1,3 @@
+on error break
+<iocshTestBadArg.cmd
+position after_error_1
diff --git a/modules/libcom/test/iocshTestSuccess.cmd b/modules/libcom/test/iocshTestSuccess.cmd
new file mode 100644
index 000000000..86c83f795
--- /dev/null
+++ b/modules/libcom/test/iocshTestSuccess.cmd
@@ -0,0 +1,8 @@
+on error break
+help
+echo This works
+pwd
+epicsThreadSleep 0.0
+epicsThreadSleep 0
+epicsThreadSleep
+position success
diff --git a/modules/libcom/test/iocshTestSuccessIndirect.cmd b/modules/libcom/test/iocshTestSuccessIndirect.cmd
new file mode 100644
index 000000000..edca2f146
--- /dev/null
+++ b/modules/libcom/test/iocshTestSuccessIndirect.cmd
@@ -0,0 +1,3 @@
+on error break
+<iocshTestSuccess.cmd
+position after_success
diff --git a/modules/libcom/test/rtemsTestData.c b/modules/libcom/test/rtemsTestData.c
deleted file mode 100644
index 7b68976c5..000000000
--- a/modules/libcom/test/rtemsTestData.c
+++ /dev/null
@@ -1,6 +0,0 @@
-#include "epicsMemFs.h"
-
-/* no local files needed for these tests,
- * so skip local FS setup
- */
-const epicsMemFS *epicsRtemsFSImage = NULL;