Update for corrected name of standard header file. Should be dlfcn.h, not dllfcn.h. I am surprised no one ever noticed before now.

examples/README.txt

@@ -1596,7 +1596,7 @@ examples/sotest
 
   This example builds a small shared library module test case.  The test
   shared library is built using the relocatable ELF format and installed
-  in a ROMFS file system.  At run time, the shared library is installed and exercised.  Requires CONFIG_LIBC_DLLFCN.  Other configuration options:
+  in a ROMFS file system.  At run time, the shared library is installed and exercised.  Requires CONFIG_LIBC_DLFCN.  Other configuration options:
 
     CONFIG_EXAMPLES_SOTEST_DEVMINOR - The minor device number of the ROMFS block
       driver. For example, the N in /dev/ramN. Used for registering the RAM

examples/sotest/Kconfig

@@ -6,7 +6,7 @@
 config EXAMPLES_SOTEST
 	tristate "Shared Library Example"
 	default n
-	depends on LIBC_DLLFCN
+	depends on LIBC_DLFCN
 	---help---
 		Enable the shared library example
 

examples/sotest/lib/modprint/modprint.c

@@ -41,7 +41,7 @@
 
 #include <sys/types.h>
 #include <stdarg.h>
-#include <dllfcn.h>
+#include <dlfcn.h>
 #include <syslog.h>
 
 #include <nuttx/symtab.h>

examples/sotest/lib/sotest/sotest.c

@@ -41,7 +41,7 @@
 
 #include <sys/types.h>
 #include <stdarg.h>
-#include <dllfcn.h>
+#include <dlfcn.h>
 #include <syslog.h>
 
 #include <nuttx/symtab.h>

examples/sotest/sotest_main.c

@@ -46,7 +46,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <syslog.h>
-#include <dllfcn.h>
+#include <dlfcn.h>
 #include <errno.h>
 #include <debug.h>
 
@@ -65,8 +65,8 @@
  * are required -- only the more obvious.
  */
 
-#ifndef CONFIG_LIBC_DLLFCN
-#  error "You must select CONFIG_LIBC_DLLFCN in your configuration file"
+#ifndef CONFIG_LIBC_DLFCN
+#  error "You must select CONFIG_LIBC_DLFCN in your configuration file"
 #endif
 
 #ifdef CONFIG_EXAMPLES_SOTEST_BUILTINFS