diff --git a/libguile/ChangeLog b/libguile/ChangeLog
index 3f71b2649..078f54d1b 100644
--- a/libguile/ChangeLog
+++ b/libguile/ChangeLog
@@ -1,3 +1,18 @@
+Thu Mar 13 21:28:25 1997  Gary Houston  <ghouston@actrix.gen.nz>
+
+	* ioext.c (scm_read_delimited_x): use RO string macros for delims.
+	(scm_freopen): use RO string macros for filename and modes.
+	(scm_duplicate_port, scm_fdopen): use RO string macros for modes.
+
+	* posix.c (scm_getgrgid): simplify conversion of name to C string.
+	(scm_mknod): use RO string macros for path.
+
+	* socket.c (scm_fill_sockaddr, scm_send, scm_sendto):
+	use SCM_ROSTRINGP, SCM_ROCHARS, SCM_ROLENGTH.
+	
+	* net_db.c (scm_gethost, scm_getnet, scm_getproto, scm_getserv):
+	use SCM_ROSTRINGP and SCM_ROCHARS.
+
 Thu Mar 13 18:31:33 1997  Mikael Djurfeldt  <mdj@mdj.nada.kth.se>
 
 	* unif.c (scm_array_set_x): Cast ICHR (obj) to char if storing in
diff --git a/libguile/ioext.c b/libguile/ioext.c
index 694dd5739..7914b4877 100644
--- a/libguile/ioext.c
+++ b/libguile/ioext.c
@@ -79,10 +79,10 @@ scm_read_delimited_x (delims, buf, gobble, port, start, end)
   char *cdelims;
   int num_delims;
 
-  SCM_ASSERT (SCM_NIMP (delims) && SCM_STRINGP (delims),
+  SCM_ASSERT (SCM_NIMP (delims) && SCM_ROSTRINGP (delims),
 	      delims, SCM_ARG1, s_read_delimited_x);
-  cdelims = SCM_CHARS (delims);
-  num_delims = SCM_LENGTH (delims);
+  cdelims = SCM_ROCHARS (delims);
+  num_delims = SCM_ROLENGTH (delims);
   SCM_ASSERT (SCM_NIMP (buf) && SCM_STRINGP (buf),
 	      buf, SCM_ARG2, s_read_delimited_x);
   cbuf = SCM_CHARS (buf);
@@ -203,11 +203,14 @@ scm_freopen (filename, modes, port)
      SCM port;
 {
   FILE *f;
-  SCM_ASSERT (SCM_NIMP (filename) && SCM_STRINGP (filename), filename, SCM_ARG1, s_freopen);
-  SCM_ASSERT (SCM_NIMP (modes) && SCM_STRINGP (modes), modes, SCM_ARG2, s_freopen);
+  SCM_ASSERT (SCM_NIMP (filename) && SCM_ROSTRINGP (filename), filename,
+	      SCM_ARG1, s_freopen);
+  SCM_ASSERT (SCM_NIMP (modes) && SCM_ROSTRINGP (modes), modes, SCM_ARG2,
+	      s_freopen);
   SCM_DEFER_INTS;
   SCM_ASSERT (SCM_NIMP (port) && SCM_FPORTP (port), port, SCM_ARG3, s_freopen);
-  SCM_SYSCALL (f = freopen (SCM_CHARS (filename), SCM_CHARS (modes), (FILE *)SCM_STREAM (port)));
+  SCM_SYSCALL (f = freopen (SCM_ROCHARS (filename), SCM_ROCHARS (modes),
+			    (FILE *)SCM_STREAM (port)));
   if (!f)
     {
       SCM p;
@@ -218,9 +221,9 @@ scm_freopen (filename, modes, port)
     }
   else
     {
-      SCM_SETCAR (port, scm_tc16_fport | scm_mode_bits (SCM_CHARS (modes)));
+      SCM_SETCAR (port, scm_tc16_fport | scm_mode_bits (SCM_ROCHARS (modes)));
       SCM_SETSTREAM (port, (SCM)f);
-      SCM_SETCAR (port, scm_tc16_fport | scm_mode_bits (SCM_CHARS (modes)));
+      SCM_SETCAR (port, scm_tc16_fport | scm_mode_bits (SCM_ROCHARS (modes)));
       if (SCM_BUF0 & SCM_CAR (port))
 	scm_setbuf0 (port);
     }
@@ -241,8 +244,10 @@ scm_duplicate_port (oldpt, modes)
   int newfd;
   FILE *f;
   SCM newpt;
-  SCM_ASSERT (SCM_NIMP (oldpt) && SCM_OPPORTP (oldpt), oldpt, SCM_ARG1, s_duplicate_port);
-  SCM_ASSERT (SCM_NIMP (modes) && SCM_STRINGP (modes), modes, SCM_ARG2, s_duplicate_port);
+  SCM_ASSERT (SCM_NIMP (oldpt) && SCM_OPPORTP (oldpt), oldpt, SCM_ARG1,
+	      s_duplicate_port);
+  SCM_ASSERT (SCM_NIMP (modes) && SCM_ROSTRINGP (modes), modes, SCM_ARG2,
+	      s_duplicate_port);
   SCM_NEWCELL (newpt);
   SCM_DEFER_INTS;
   oldfd = fileno ((FILE *)SCM_STREAM (oldpt));
@@ -251,7 +256,7 @@ scm_duplicate_port (oldpt, modes)
   SCM_SYSCALL (newfd = dup (oldfd));
   if (newfd == -1)
     scm_syserror (s_duplicate_port);
-  f = fdopen (newfd, SCM_CHARS (modes));
+  f = fdopen (newfd, SCM_ROCHARS (modes));
   if (!f)
     {
       SCM_SYSCALL (close (newfd));
@@ -261,7 +266,7 @@ scm_duplicate_port (oldpt, modes)
     struct scm_port_table * pt;
     pt = scm_add_to_port_table (newpt);
     SCM_SETPTAB_ENTRY (newpt, pt);
-    SCM_SETCAR (newpt, scm_tc16_fport | scm_mode_bits (SCM_CHARS (modes)));
+    SCM_SETCAR (newpt, scm_tc16_fport | scm_mode_bits (SCM_ROCHARS (modes)));
     if (SCM_BUF0 & SCM_CAR (newpt))
       scm_setbuf0 (newpt);
     SCM_SETSTREAM (newpt, (SCM)f);
@@ -340,15 +345,16 @@ scm_fdopen (fdes, modes)
   struct scm_port_table * pt;
 
   SCM_ASSERT (SCM_INUMP (fdes), fdes, SCM_ARG1, s_fdopen);
-  SCM_ASSERT (SCM_NIMP (modes) && SCM_STRINGP (modes), modes, SCM_ARG2, s_fdopen);
+  SCM_ASSERT (SCM_NIMP (modes) && SCM_ROSTRINGP (modes), modes, SCM_ARG2,
+	      s_fdopen);
   SCM_NEWCELL (port);
   SCM_DEFER_INTS;
-  f = fdopen (SCM_INUM (fdes), SCM_CHARS (modes));
+  f = fdopen (SCM_INUM (fdes), SCM_ROCHARS (modes));
   if (f == NULL)
     scm_syserror (s_fdopen);
   pt = scm_add_to_port_table (port);
   SCM_SETPTAB_ENTRY (port, pt);
-  SCM_SETCAR (port, scm_tc16_fport | scm_mode_bits (SCM_CHARS (modes)));
+  SCM_SETCAR (port, scm_tc16_fport | scm_mode_bits (SCM_ROCHARS (modes)));
   if (SCM_BUF0 & SCM_CAR (port))
     scm_setbuf0 (port);
   SCM_SETSTREAM (port, (SCM)f);
diff --git a/libguile/net_db.c b/libguile/net_db.c
index 0e21667e9..fccff300b 100644
--- a/libguile/net_db.c
+++ b/libguile/net_db.c
@@ -171,10 +171,10 @@ scm_gethost (name)
     }
   else
 #endif
-  if (SCM_NIMP (name) && SCM_STRINGP (name))
+  if (SCM_NIMP (name) && SCM_ROSTRINGP (name))
     {
       SCM_DEFER_INTS;
-      entry = gethostbyname (SCM_CHARS (name));
+      entry = gethostbyname (SCM_ROCHARS (name));
     }
   else
     {
@@ -222,10 +222,10 @@ scm_getnet (name)
       SCM_DEFER_INTS;
       entry = getnetent ();
     }
-  else if (SCM_NIMP (name) && SCM_STRINGP (name))
+  else if (SCM_NIMP (name) && SCM_ROSTRINGP (name))
     {
       SCM_DEFER_INTS;
-      entry = getnetbyname (SCM_CHARS (name));
+      entry = getnetbyname (SCM_ROCHARS (name));
     }
   else
     {
@@ -261,10 +261,10 @@ scm_getproto (name)
       SCM_DEFER_INTS;
       entry = getprotoent ();
     }
-  else if (SCM_NIMP (name) && SCM_STRINGP (name))
+  else if (SCM_NIMP (name) && SCM_ROSTRINGP (name))
     {
       SCM_DEFER_INTS;
-      entry = getprotobyname (SCM_CHARS (name));
+      entry = getprotobyname (SCM_ROCHARS (name));
     }
   else
     {
@@ -319,17 +319,17 @@ scm_getserv (name, proto)
       SCM_ALLOW_INTS;
       return scm_return_entry (entry);
     }
-  SCM_ASSERT (SCM_NIMP (proto) && SCM_STRINGP (proto), proto, SCM_ARG2, s_getserv);
-  if (SCM_NIMP (name) && SCM_STRINGP (name))
+  SCM_ASSERT (SCM_NIMP (proto) && SCM_ROSTRINGP (proto), proto, SCM_ARG2, s_getserv);
+  if (SCM_NIMP (name) && SCM_ROSTRINGP (name))
     {
       SCM_DEFER_INTS;
-      entry = getservbyname (SCM_CHARS (name), SCM_CHARS (proto));
+      entry = getservbyname (SCM_ROCHARS (name), SCM_ROCHARS (proto));
     }
   else
     {
       SCM_ASSERT (SCM_INUMP (name), name, SCM_ARG1, s_getserv);
       SCM_DEFER_INTS;
-      entry = getservbyport (htons (SCM_INUM (name)), SCM_CHARS (proto));
+      entry = getservbyport (htons (SCM_INUM (name)), SCM_ROCHARS (proto));
     }
   if (!entry)
     scm_syserror (s_getserv);
diff --git a/libguile/posix.c b/libguile/posix.c
index a7a19b742..9016dd2d6 100644
--- a/libguile/posix.c
+++ b/libguile/posix.c
@@ -353,10 +353,9 @@ scm_getgrgid (name)
     SCM_SYSCALL (entry = getgrgid (SCM_INUM (name)));
   else
     {
-      SCM_ASSERT (SCM_NIMP (name) && SCM_STRINGP (name), name, SCM_ARG1, s_getgrgid);
-      if (SCM_SUBSTRP (name))
-	name = scm_makfromstr (SCM_ROCHARS (name), SCM_ROLENGTH (name), 0);
-      SCM_SYSCALL (entry = getgrnam (SCM_CHARS (name)));
+      SCM_ASSERT (SCM_NIMP (name) && SCM_ROSTRINGP (name), name, SCM_ARG1,
+		  s_getgrgid);
+      SCM_SYSCALL (entry = getgrnam (SCM_ROCHARS (name)));
     }
   if (!entry)
     scm_syserror (s_getgrgid);
@@ -698,8 +697,8 @@ scm_convert_exec_args (args)
       scm_sizet len;
       char *dst;
       char *src;
-      SCM_ASSERT (SCM_NIMP (SCM_CAR (args)) && SCM_ROSTRINGP (SCM_CAR (args)), SCM_CAR (args),
-	      "wrong type in SCM_ARG", "exec arg");
+      SCM_ASSERT (SCM_NIMP (SCM_CAR (args)) && SCM_ROSTRINGP (SCM_CAR (args)),
+		  SCM_CAR (args), "wrong type in SCM_ARG", "exec arg");
       len = 1 + SCM_ROLENGTH (SCM_CAR (args));
       dst = (char *) scm_must_malloc ((long) len, s_ttyname);
       src = SCM_ROCHARS (SCM_CAR (args));
@@ -739,9 +738,11 @@ scm_execlp (args)
 {
   char **execargv;
   SCM filename = SCM_CAR (args);
-  SCM_ASSERT (SCM_NIMP (filename) && SCM_ROSTRINGP (filename), filename, SCM_ARG1, s_execlp);
+  SCM_ASSERT (SCM_NIMP (filename) && SCM_ROSTRINGP (filename), filename,
+	      SCM_ARG1, s_execlp);
   if (SCM_SUBSTRP (filename))
-    filename = scm_makfromstr (SCM_ROCHARS (filename), SCM_ROLENGTH (filename), 0);
+    filename = scm_makfromstr (SCM_ROCHARS (filename),
+			       SCM_ROLENGTH (filename), 0);
   args = SCM_CDR (args);
   execargv = scm_convert_exec_args (args);
   execvp (SCM_ROCHARS (filename), execargv);
@@ -814,8 +815,9 @@ scm_environ (env)
 	{
 	  int len;
 	  char *src;
-	  SCM_ASSERT (SCM_NIMP (SCM_CAR (env)) && SCM_ROSTRINGP (SCM_CAR (env)), env, SCM_ARG1,
-		  s_environ);
+	  SCM_ASSERT (SCM_NIMP (SCM_CAR (env))
+		      && SCM_ROSTRINGP (SCM_CAR (env)),
+		      env, SCM_ARG1, s_environ);
 	  len = 1 + SCM_ROLENGTH (SCM_CAR (env));
 	  new_environ[i] = scm_must_malloc ((long) len, s_environ);
 	  src = SCM_ROCHARS (SCM_CAR (env));
@@ -867,10 +869,13 @@ scm_open_pipe (pipestr, modes)
   register SCM z;
   struct scm_port_table * pt;
 
-  SCM_ASSERT (SCM_NIMP (pipestr) && SCM_ROSTRINGP (pipestr), pipestr, SCM_ARG1, s_open_pipe);
+  SCM_ASSERT (SCM_NIMP (pipestr) && SCM_ROSTRINGP (pipestr), pipestr,
+	      SCM_ARG1, s_open_pipe);
   if (SCM_SUBSTRP (pipestr))
-    pipestr = scm_makfromstr (SCM_ROCHARS (pipestr), SCM_ROLENGTH (pipestr), 0);
-  SCM_ASSERT (SCM_NIMP (modes) && SCM_ROSTRINGP (modes), modes, SCM_ARG2, s_open_pipe);
+    pipestr = scm_makfromstr (SCM_ROCHARS (pipestr),
+			      SCM_ROLENGTH (pipestr), 0);
+  SCM_ASSERT (SCM_NIMP (modes) && SCM_ROSTRINGP (modes), modes, SCM_ARG2,
+	      s_open_pipe);
   if (SCM_SUBSTRP (modes))
     modes = scm_makfromstr (SCM_ROCHARS (modes), SCM_ROLENGTH (modes), 0);
   SCM_NEWCELL (z);
@@ -920,7 +925,8 @@ scm_utime (pathname, actime, modtime)
   int rv;
   struct utimbuf utm_tmp;
 
-  SCM_ASSERT (SCM_NIMP (pathname) && SCM_STRINGP (pathname), pathname, SCM_ARG1, s_utime);
+  SCM_ASSERT (SCM_NIMP (pathname) && SCM_STRINGP (pathname), pathname,
+	      SCM_ARG1, s_utime);
 
   if (SCM_UNBNDP (actime))
     SCM_SYSCALL (time (&utm_tmp.actime));
@@ -947,7 +953,8 @@ scm_access (path, how)
 {
   int rv;
 
-  SCM_ASSERT (SCM_NIMP (path) && SCM_ROSTRINGP (path), path, SCM_ARG1, s_access);
+  SCM_ASSERT (SCM_NIMP (path) && SCM_ROSTRINGP (path), path, SCM_ARG1,
+	      s_access);
   if (SCM_SUBSTRP (path))
     path = scm_makfromstr (SCM_ROCHARS (path), SCM_ROLENGTH (path), 0);
   SCM_ASSERT (SCM_INUMP (how), how, SCM_ARG2, s_access);
@@ -1002,7 +1009,8 @@ scm_setlocale (category, locale)
     }
   else
     {
-      SCM_ASSERT (SCM_NIMP (locale) && SCM_STRINGP (locale), locale, SCM_ARG2, s_setlocale);
+      SCM_ASSERT (SCM_NIMP (locale) && SCM_STRINGP (locale), locale,
+		  SCM_ARG2, s_setlocale);
       clocale = SCM_CHARS (locale);
     }
 
@@ -1032,9 +1040,11 @@ scm_strftime (format, stime)
   char *fmt;
   int len;
 
-  SCM_ASSERT (SCM_NIMP (format) && SCM_STRINGP (format), format, SCM_ARG1, s_strftime);
-  SCM_ASSERT (SCM_NIMP (stime) && SCM_VECTORP (stime) && scm_obj_length (stime) == 9,
-	  stime, SCM_ARG2, s_strftime);
+  SCM_ASSERT (SCM_NIMP (format) && SCM_STRINGP (format), format, SCM_ARG1,
+	      s_strftime);
+  SCM_ASSERT (SCM_NIMP (stime) && SCM_VECTORP (stime)
+	      && scm_obj_length (stime) == 9,
+	      stime, SCM_ARG2, s_strftime);
 
   fmt = SCM_ROCHARS (format);
   len = SCM_ROLENGTH (format);
@@ -1080,10 +1090,12 @@ scm_strptime (format, string)
   char *fmt, *str, *rest;
   int n;
 
-  SCM_ASSERT (SCM_NIMP (format) && SCM_ROSTRINGP (format), format, SCM_ARG1, s_strptime);
+  SCM_ASSERT (SCM_NIMP (format) && SCM_ROSTRINGP (format), format, SCM_ARG1,
+	      s_strptime);
   if (SCM_SUBSTRP (format))
     format =  scm_makfromstr (SCM_ROCHARS (format), SCM_ROLENGTH (format), 0);
-  SCM_ASSERT (SCM_NIMP (string) && SCM_ROSTRINGP (string), string, SCM_ARG2, s_strptime);
+  SCM_ASSERT (SCM_NIMP (string) && SCM_ROSTRINGP (string), string, SCM_ARG2,
+	      s_strptime);
   if (SCM_SUBSTRP (string))
     string =  scm_makfromstr (SCM_ROCHARS (string), SCM_ROLENGTH (string), 0);
 
@@ -1143,10 +1155,10 @@ scm_mknod(path, mode, dev)
 {
 #ifdef HAVE_MKNOD
   int val;
-  SCM_ASSERT(SCM_NIMP(path) && SCM_STRINGP(path), path, SCM_ARG1, s_mknod);
+  SCM_ASSERT(SCM_NIMP(path) && SCM_ROSTRINGP(path), path, SCM_ARG1, s_mknod);
   SCM_ASSERT(SCM_INUMP(mode), mode, SCM_ARG2, s_mknod);
   SCM_ASSERT(SCM_INUMP(dev), dev, SCM_ARG3, s_mknod);
-  SCM_SYSCALL(val = mknod(SCM_CHARS(path), SCM_INUM(mode), SCM_INUM(dev)));
+  SCM_SYSCALL(val = mknod(SCM_ROCHARS(path), SCM_INUM(mode), SCM_INUM(dev)));
   if (val != 0)
     scm_syserror (s_mknod);
   return SCM_UNSPECIFIED;
diff --git a/libguile/socket.c b/libguile/socket.c
index e4a817796..1dcccb3d6 100644
--- a/libguile/socket.c
+++ b/libguile/socket.c
@@ -356,9 +356,10 @@ scm_fill_sockaddr (fam, address, args, which_arg, proc, size)
 	soka = (struct sockaddr_un *)
 	  scm_must_malloc (sizeof (struct sockaddr_un), proc);
 	soka->sun_family = AF_UNIX;
-	SCM_ASSERT (SCM_NIMP (address) && SCM_STRINGP (address), address,
-		which_arg, proc);
-	memcpy (soka->sun_path, SCM_CHARS (address), 1 + SCM_LENGTH (address));
+	SCM_ASSERT (SCM_NIMP (address) && SCM_ROSTRINGP (address), address,
+		    which_arg, proc);
+	memcpy (soka->sun_path, SCM_ROCHARS (address),
+		1 + SCM_ROLENGTH (address));
 	*size = sizeof (struct sockaddr_un);
 	return (struct sockaddr *) soka;
       }
@@ -599,7 +600,7 @@ scm_send (sock, message, flags)
   int flg;
 
   SCM_ASSERT (SCM_NIMP (sock) && SCM_FPORTP (sock), sock, SCM_ARG1, s_send);
-  SCM_ASSERT (SCM_NIMP (message) && SCM_STRINGP (message), message, SCM_ARG2, s_send);
+  SCM_ASSERT (SCM_NIMP (message) && SCM_ROSTRINGP (message), message, SCM_ARG2, s_send);
   fd = fileno ((FILE *)SCM_STREAM (sock));
 
   if (SCM_UNBNDP (flags))
@@ -607,7 +608,7 @@ scm_send (sock, message, flags)
   else
     flg = scm_num2ulong (flags, (char *) SCM_ARG3, s_send);
 
-  SCM_SYSCALL (rv = send (fd, SCM_CHARS (message), SCM_LENGTH (message), flg));
+  SCM_SYSCALL (rv = send (fd, SCM_ROCHARS (message), SCM_ROLENGTH (message), flg));
   if (rv == -1)
     scm_syserror (s_send);
   return SCM_MAKINUM (rv);
@@ -697,7 +698,8 @@ scm_sendto (sock, message, fam, address, args_and_flags)
   scm_sizet size;
 
   SCM_ASSERT (SCM_NIMP (sock) && SCM_FPORTP (sock), sock, SCM_ARG1, s_sendto);
-  SCM_ASSERT (SCM_NIMP (message) && SCM_STRINGP (message), message, SCM_ARG2, s_sendto);
+  SCM_ASSERT (SCM_NIMP (message) && SCM_ROSTRINGP (message), message,
+	      SCM_ARG2, s_sendto);
   SCM_ASSERT (SCM_INUMP (fam), fam, SCM_ARG3, s_sendto);
   fd = fileno ((FILE *)SCM_STREAM (sock));
   SCM_DEFER_INTS;
@@ -711,8 +713,8 @@ scm_sendto (sock, message, fam, address, args_and_flags)
 	      args_and_flags, SCM_ARG5, s_sendto);
       flg = scm_num2ulong (SCM_CAR (args_and_flags), (char *) SCM_ARG5, s_sendto);
     }
-  SCM_SYSCALL (rv = sendto (fd, SCM_CHARS (message), SCM_LENGTH (message), flg,
-			soka, size));
+  SCM_SYSCALL (rv = sendto (fd, SCM_ROCHARS (message), SCM_ROLENGTH (message),
+			    flg, soka, size));
   if (rv == -1)
     scm_syserror (s_sendto);
   scm_must_free ((char *) soka);