This patch adds shl_load (old HP-UX) support to bash 4.2 for enabling
loadable builtins.  In order for bash on HP-UX to actually load most of
the builtins, it must be linked with the linker's -E flag as well, so
you'll need to do something like this:

 .../bash-4.2$ patch -p1 < ../bash-4.2-shl.diff
 .../bash-4.2$ autoconf
 .../bash-4.2$ CC=gcc LDFLAGS=-Wl,-E ./configure
 .../bash-4.2$ make

If you're using the native HP-UX compiler, then the options may differ.

diff -ur bash-4.2/builtins/enable.def bash-4.2-shl/builtins/enable.def
--- bash-4.2/builtins/enable.def	Sun Jan  4 14:32:22 2009
+++ bash-4.2-shl/builtins/enable.def	Fri Oct  5 08:13:38 2012
@@ -82,11 +82,11 @@
 #define PFLAG	0x10
 #define SFLAG	0x20
 
-#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+#if (defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)) || (defined (HAVE_SHL_LOAD) && defined (HAVE_SHL_FINDSYM))
 static int dyn_load_builtin __P((WORD_LIST *, int, char *));
 #endif
 
-#if defined (HAVE_DLCLOSE)
+#if defined (HAVE_DLCLOSE) || defined (HAVE_SHL_UNLOAD)
 static int dyn_unload_builtin __P((char *));
 static void delete_builtin __P((struct builtin *));
 static int local_dlclose __P((void *));
@@ -104,7 +104,7 @@
 {
   int result, flags;
   int opt, filter;
-#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+#if (defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)) || (defined (HAVE_SHL_LOAD) && defined (HAVE_SHL_FINDSYM))
   char *filename;
 #endif
 
@@ -129,7 +129,7 @@
 	  flags |= SFLAG;
 	  break;
 	case 'f':
-#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+#if (defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)) || (defined (HAVE_SHL_LOAD) && defined (HAVE_SHL_FINDSYM))
 	  flags |= FFLAG;
 	  filename = list_optarg;
 	  break;
@@ -137,7 +137,7 @@
 	  builtin_error (_("dynamic loading not available"));
 	  return (EX_USAGE);
 #endif
-#if defined (HAVE_DLCLOSE)
+#if defined (HAVE_DLCLOSE) || defined (HAVE_SHL_UNLOAD)
 	case 'd':
 	  flags |= DFLAG;
 	  break;
@@ -172,7 +172,7 @@
 
       list_some_builtins (filter);
     }
-#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+#if (defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)) || (defined (HAVE_SHL_LOAD) && defined (HAVE_SHL_FINDSYM))
   else if (flags & FFLAG)
     {
       filter = (flags & NFLAG) ? DISABLED : ENABLED;
@@ -185,7 +185,7 @@
 #endif
     }
 #endif
-#if defined (HAVE_DLCLOSE)
+#if defined (HAVE_DLCLOSE) || defined (HAVE_SHL_UNLOAD)
   else if (flags & DFLAG)
     {
       while (list)
@@ -275,11 +275,17 @@
   return (EXECUTION_SUCCESS);
 }
 
-#if defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)
+#if (defined (HAVE_DLOPEN) && defined (HAVE_DLSYM)) || (defined (HAVE_SHL_LOAD) && defined (HAVE_SHL_FINDSYM))
 
 #if defined (HAVE_DLFCN_H)
 #  include <dlfcn.h>
 #endif
+#if defined (HAVE_DL_H)
+#  include <dl.h>
+#endif
+#if defined (HAVE_ERRNO_H)
+#  include <errno.h>
+#endif
 
 static int
 dyn_load_builtin (list, flags, filename)
@@ -288,7 +294,11 @@
      char *filename;
 {
   WORD_LIST *l;
+#if defined (HAVE_DLOPEN)
   void *handle;
+#elif defined (HAVE_SHL_LOAD)
+  shl_t handle;
+#endif
   
   int total, size, new, replaced;
   char *struct_name, *name;
@@ -301,15 +311,22 @@
 #define RTLD_LAZY 1
 #endif
 
-#if defined (_AIX)
+#if defined (HAVE_DLOPEN) && defined (_AIX)
   handle = dlopen (filename, RTLD_NOW|RTLD_GLOBAL);
-#else
+#elif defined (HAVE_DLOPEN)
   handle = dlopen (filename, RTLD_LAZY);
+#elif defined (HAVE_SHL_LOAD)
+  handle = shl_load (filename, BIND_IMMEDIATE | BIND_VERBOSE, 0L);
 #endif /* !_AIX */
 
   if (handle == 0)
     {
-      builtin_error (_("cannot open shared object %s: %s"), filename, dlerror ());
+      builtin_error (_("cannot open shared object %s: %s"), filename,
+#if defined (HAVE_DLOPEN)
+        dlerror ());
+#elif defined (HAVE_SHL_LOAD)
+        strerror (errno));
+#endif
       return (EXECUTION_FAILURE);
     }
 
@@ -329,11 +346,20 @@
       strcpy (struct_name, name);
       strcpy (struct_name + size, "_struct");
 
+#if defined (HAVE_DLSYM)
       b = (struct builtin *)dlsym (handle, struct_name);
       if (b == 0)
+#elif defined (HAVE_SHL_FINDSYM)
+      if (0 != shl_findsym (&handle, struct_name, TYPE_UNDEFINED, (void *) &b))
+#endif
 	{
 	  builtin_error (_("cannot find %s in shared object %s: %s"),
-			  struct_name, filename, dlerror ());
+			  struct_name, filename,
+#if defined (HAVE_DLOPEN)
+			  dlerror ());
+#elif defined (HAVE_SHL_LOAD)
+			  strerror (errno));
+#endif
 	  free (struct_name);
 	  continue;
 	}
@@ -357,7 +383,11 @@
   if (replaced == 0 && new == 0)
     {
       free (new_builtins);
+#if defined (HAVE_DLCLOSE)
       dlclose (handle);
+#elif defined (HAVE_SHL_UNLOAD)
+      shl_unload (handle);
+#endif
       return (EXECUTION_FAILURE);
     }
 
@@ -391,7 +421,7 @@
 }
 #endif
 
-#if defined (HAVE_DLCLOSE)
+#if defined (HAVE_DLCLOSE) || defined (HAVE_SHL_UNLOAD)
 static void
 delete_builtin (b)
      struct builtin *b;
@@ -432,12 +462,16 @@
 local_dlclose (handle)
      void *handle;
 {
+#if defined (HAVE_DLCLOSE)
 #if !defined (__MACHTEN__)
   return (dlclose (handle));
 #else /* __MACHTEN__ */
   dlclose (handle);
   return ((dlerror () != NULL) ? -1 : 0);    
 #endif /* __MACHTEN__ */
+#elif defined (HAVE_SHL_UNLOAD)
+  return (shl_unload (handle));
+#endif /* HAVE_DLCLOSE or HAVE_SHL_UNLOAD */
 }
 
 static int
@@ -471,7 +505,12 @@
      using it drops to zero. */
   if (ref == 1 && local_dlclose (handle) != 0)
     {
-      builtin_error (_("%s: cannot delete: %s"), name, dlerror ());
+      builtin_error (_("%s: cannot delete: %s"), name,
+#if defined (HAVE_DLOPEN)
+        dlerror ());
+#elif defined (HAVE_SHL_LOAD)
+        strerror (errno));
+#endif
       return (EXECUTION_FAILURE);
     }
 
diff -ur bash-4.2/config.h.in bash-4.2-shl/config.h.in
--- bash-4.2/config.h.in	Mon Aug  2 20:53:10 2010
+++ bash-4.2-shl/config.h.in	Fri Oct  5 08:13:37 2012
@@ -548,6 +548,15 @@
 /* Define if you have the dlsym function.  */
 #undef HAVE_DLSYM
 
+/* Define if you have the shl_load function. */
+#undef HAVE_SHL_LOAD
+
+/* Define if you have the shl_unload function. */
+#undef HAVE_SHL_UNLOAD
+
+/* Define if you have the shl_findsym function. */
+#undef HAVE_SHL_FINDSYM
+
 /* Define if you don't have vprintf but do have _doprnt.  */
 #undef HAVE_DOPRNT
 
@@ -894,6 +903,9 @@
 
 /* Define if you have the <dirent.h> header file.  */
 #undef HAVE_DIRENT_H
+
+/* Define if you have the <dl.h> header file.  */
+#undef HAVE_DL_H
 
 /* Define if you have the <dlfcn.h> header file.  */
 #undef HAVE_DLFCN_H
diff -ur bash-4.2/configure.in bash-4.2-shl/configure.in
--- bash-4.2/configure.in	Mon Feb  7 17:03:14 2011
+++ bash-4.2-shl/configure.in	Fri Oct  5 08:14:08 2012
@@ -657,7 +657,7 @@
 BASH_HEADER_INTTYPES
 
 AC_CHECK_HEADERS(unistd.h stdlib.h stdarg.h varargs.h limits.h string.h \
-		 memory.h locale.h termcap.h termio.h termios.h dlfcn.h \
+		 memory.h locale.h termcap.h termio.h termios.h dl.h dlfcn.h \
 		 stddef.h stdint.h netdb.h pwd.h grp.h strings.h regex.h \
 		 syslog.h ulimit.h)
 AC_CHECK_HEADERS(sys/pte.h sys/stream.h sys/select.h sys/file.h \
@@ -808,6 +808,8 @@
 if test "$opt_static_link" != yes; then
 AC_CHECK_LIB(dl, dlopen)
 AC_CHECK_FUNCS(dlopen dlclose dlsym)
+AC_CHECK_LIB(dld, shl_load)
+AC_CHECK_FUNCS(shl_load shl_unload shl_findsym)
 fi
 
 dnl this defines HAVE_DECL_SYS_SIGLIST
@@ -1078,7 +1080,8 @@
 # Shared object configuration section.  These values are generated by
 # ${srcdir}/support/shobj-conf
 #
-if test "$ac_cv_func_dlopen" = "yes" && test -f ${srcdir}/support/shobj-conf
+if ( test "$ac_cv_func_dlopen" = "yes" || test "$ac_cv_func_shl_load" = "yes" )\
+  && test -f ${srcdir}/support/shobj-conf
 then
 	AC_MSG_CHECKING(shared object configuration for loadable builtins)
 	eval `${CONFIG_SHELL-/bin/sh} ${srcdir}/support/shobj-conf -C "${CC}" -c "${host_cpu}" -o "${host_os}" -v "${host_vendor}"`