Mercurial > hg > octave-nkf

changeset 1728:42b4f904f1af

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[project @ 1996-01-09 11:36:01 by jwe]
author jwe
date Tue, 09 Jan 1996 11:41:43 +0000
parents ba9b08842dbe
children 227706b05144
files liboctave/chMatrix.cc liboctave/chMatrix.h src/balance.cc src/colloc.cc src/dassl.cc src/data.cc src/dirfns.cc src/error.cc src/file-io.cc src/fsolve.cc src/input.cc src/load-save.cc src/lsode.cc src/npsol.cc src/pr-output.cc src/pt-const.cc src/pt-const.h src/pt-plot.cc src/qpsol.cc src/quad.cc src/rand.cc src/schur.cc src/sysdep.cc src/timefns.cc src/toplev.cc src/utils.cc src/variables.cc
diffstat 27 files changed, 224 insertions(+), 86 deletions(-) [+]
line wrap: on
line diff
--- a/liboctave/chMatrix.cc
+++ b/liboctave/chMatrix.cc
@@ -32,6 +32,8 @@
 #include <cstdio>
 #include <cstring>
 
+#include <string>
+
 #include <iostream.h>
 
 // #include <sys/types.h>  // XXX FIXME XXX
@@ -91,7 +93,7 @@
   return *this;
 }
 
-char *
+string
 charMatrix::row_as_string (int r) const
 {
   if (r < 0 || r >= rows ())
@@ -102,9 +104,7 @@
 
   int nc = cols ();
 
-  char *retval = new char [nc + 1];
-
-  retval[nc] = '\0';
+  string retval (nc, '\0');
 
   for (int i = 0; i < nc; i++)
     retval[i] = elem (r, i);
--- a/liboctave/chMatrix.h
+++ b/liboctave/chMatrix.h
@@ -31,11 +31,14 @@
 // For FILE...
 #include <cstdio>
 
+#include <string>
+
 #include "MArray.h"
 
 #include "mx-defs.h"
 
-class charMatrix : public MArray2<char>
+class
+charMatrix : public MArray2<char>
 {
 friend class ComplexMatrix;
 
@@ -62,7 +65,7 @@
   charMatrix& insert (const char *s, int r, int c);
   charMatrix& insert (const charMatrix& a, int r, int c);
 
-  char *row_as_string (int r) const;
+  string row_as_string (int r) const;
 
 #if 0
   Matrix& insert (const RowVector& a, int r, int c);
--- a/src/balance.cc
+++ b/src/balance.cc
@@ -27,6 +27,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include "CMatrix.h"
 #include "CmplxAEPBAL.h"
 #include "CmplxAEPBAL.h"
@@ -73,6 +75,7 @@
     }
 
   const char *bal_job;
+  string tstr;
   int my_nargin;		// # args w/o optional string arg
 
   // Determine if balancing option is listed.  Set my_nargin to the
@@ -80,7 +83,8 @@
 
   if (args(nargin-1).is_string ())
     {
-      bal_job = args(nargin-1).string_value ();
+      tstr = args(nargin-1).string_value ();
+      bal_job = tstr.c_str ();
       my_nargin = nargin-1;
     }
   else
--- a/src/colloc.cc
+++ b/src/colloc.cc
@@ -25,6 +25,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include "CollocWt.h"
 
 #include "defun-dld.h"
@@ -84,7 +86,8 @@
 	      return retval;
 	    }
 
-	  const char *s = args(i).string_value ();
+	  string tstr = args(i).string_value ();
+	  const char *s = tstr.c_str ();
 
 	  if (s && (((*s == 'R' || *s == 'r') && strlen (s) == 1)
 		    || strcmp (s, "right") == 0))
--- a/src/dassl.cc
+++ b/src/dassl.cc
@@ -25,6 +25,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include <strstream.h>
 
 #include "DAE.h"
@@ -333,7 +335,8 @@
     }
   else if (nargin == 1 || nargin == 2)
     {
-      const char *keyword = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *keyword = tstr.c_str ();
 
       if (! error_state)
 	{
--- a/src/data.cc
+++ b/src/data.cc
@@ -33,6 +33,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include "defun.h"
 #include "error.h"
 #include "gripes.h"
@@ -804,7 +806,8 @@
       retval = 0.0;
       if (args(0).is_map () && args(1).is_string ())
 	{
-	  const char *s = args(1).string_value ();
+	  string tstr = args(1).string_value ();
+	  const char *s = tstr.c_str ();
 	  tree_constant tmp = args(0).lookup_map_element (s, 0, 1);
 	  retval = (double) tmp.is_defined ();
 	}
--- a/src/dirfns.cc
+++ b/src/dirfns.cc
@@ -44,6 +44,8 @@
 #include <cstdlib>
 #include <cstring>
 
+#include <string>
+
 #include <strstream.h>
 
 #include "defun.h"
@@ -501,7 +503,8 @@
 
   if (args.length () == 1)
     {
-      const char *dirname = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *dirname = tstr.c_str ();
 
       if (error_state)
 	{
@@ -590,7 +593,8 @@
 
   if (args.length () == 1)
     {
-      const char *dirname = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *dirname = tstr.c_str ();
 
       if (error_state)
 	gripe_wrong_type_arg ("mkdir", args(0));
@@ -630,7 +634,8 @@
 
   if (args.length () == 1)
     {
-      const char *dirname = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *dirname = tstr.c_str ();
 
       if (error_state)
 	gripe_wrong_type_arg ("rmdir", args(0));
@@ -670,12 +675,16 @@
 
   if (args.length () == 2)
     {
-      const char *from = args(0).string_value ();
+      string tstr1 = args(0).string_value ();
+      const char *from = tstr1.c_str ();
+
       if (error_state)
 	gripe_wrong_type_arg ("rename", args(0));
       else
 	{
-	  const char *to = args(1).string_value ();
+	  string tstr2 = args(1).string_value ();
+	  const char *to = tstr2.c_str ();
+
 	  if (error_state)
 	    gripe_wrong_type_arg ("rename", args(1));
 	  else if (rename (from, to) < 0)
--- a/src/error.cc
+++ b/src/error.cc
@@ -28,6 +28,8 @@
 #include <cstdarg>
 #include <cstring>
 
+#include <string>
+
 #include <strstream.h>
 
 #include "defun.h"
@@ -202,6 +204,8 @@
 {
   Octave_object retval;
 
+  string tstr;
+
   int nargin = args.length ();
 
   tree_constant arg = ((nargin > 1) ? Fsprintf (args, 1) : args) (0);
@@ -210,7 +214,8 @@
     {
       if (arg.is_string ())
 	{
-	  msg = arg.string_value ();
+	  tstr = arg.string_value ();
+	  msg = tstr.c_str ();
 
 	  if (! msg)
 	    return retval;
--- a/src/file-io.cc
+++ b/src/file-io.cc
@@ -39,6 +39,8 @@
 #include <cstdlib>
 #include <cctype>
 
+#include <string>
+
 #include <strstream.h>
 
 #ifdef HAVE_UNISTD_H
@@ -115,7 +117,8 @@
       int file_count = file_list.length ();
       for (int i = 0; i < file_count; i++)
 	{
-	  const char *file_name = arg.string_value ();
+	  string tstr = arg.string_value ();
+	  const char *file_name = tstr.c_str ();
 	  file = file_list (p);
 	  if (file.name () == file_name)
 	    return p;
@@ -191,7 +194,8 @@
     {
       if (arg.is_string ())
 	{
-	  const char *name = arg.string_value ();
+	  string tstr = arg.string_value ();
+	  const char *name = tstr.c_str ();
 
 	  struct stat buffer;
 	  int status = stat (name, &buffer);
@@ -481,8 +485,10 @@
       return retval;
     }
 
-  const char *name = args(0).string_value ();
-  const char *mode = args(1).string_value ();
+  string tstr1 = args(0).string_value ();
+  const char *name = tstr1.c_str ();
+  string tstr2 = args(1).string_value ();
+  const char *mode = tstr2.c_str ();
 
   if (! valid_mode (mode))
     {
@@ -935,7 +941,8 @@
 
     case 's':
       {
-	const char *val = args(fmt_arg_count++).string_value ();
+	string tstr = args(fmt_arg_count++).string_value ();
+	const char *val = tstr.c_str ();
 
 	if (error_state)
 	  goto invalid_conversion;
@@ -952,7 +959,8 @@
 
     case 'c':
       {
-	const char *val = args(fmt_arg_count++).string_value ();
+	string tstr = args(fmt_arg_count++).string_value ();
+	const char *val = tstr.c_str ();
 
 	if (error_state || strlen (val) != 1)
 	  goto invalid_conversion;
@@ -988,6 +996,7 @@
   Octave_object retval;
   fmt_arg_count = 0;
   const char *fmt;
+  string fmt_str;
   file_info file;
 
   if (strcmp (type, "fprintf") == 0)
@@ -1005,7 +1014,8 @@
 	  return retval;
 	}
 
-      fmt = args(1).string_value ();
+      fmt_str = args(1).string_value ();
+      fmt = fmt_str.c_str ();
 
       if (error_state)
 	{
@@ -1017,7 +1027,8 @@
     }
   else
     {
-      fmt = args(0).string_value ();
+      fmt_str = args(0).string_value ();
+      fmt = fmt_str.c_str ();
 
       if (error_state)
 	{
@@ -1308,6 +1319,7 @@
 {
   Octave_object retval;
   const char *scanf_fmt = 0;
+  string scanf_fmt_str;
   char *tmp_file = 0;
   int tmp_file_open = 0;
   FILE *fptr = 0;
@@ -1317,7 +1329,8 @@
 
   if (strcmp (type, "scanf") != 0)
     {
-      scanf_fmt = args(1).string_value ();
+      scanf_fmt_str = args(1).string_value (); 
+      scanf_fmt = scanf_fmt_str.c_str ();
 
       if (error_state)
 	{
@@ -1349,10 +1362,14 @@
   if ((! fptr && args(0).is_string ())
       || (doing_fscanf && file.number () == 0))
     {
-      const char *string;
+      string xstring_str;
+      const char *xstring;
 
       if (strcmp (type, "scanf") == 0)
-	scanf_fmt = args(0).string_value ();
+	{
+	  scanf_fmt_str = args(0).string_value ();
+	  scanf_fmt = scanf_fmt_str.c_str ();
+	}
 
       if (strcmp (type, "scanf") == 0
 	  || (doing_fscanf && file.number () == 0))
@@ -1364,13 +1381,16 @@
 
 	  flush_output_to_pager ();
 
-	  string = gnu_readline ("");
-
-	  if (string && *string)
-	    maybe_save_history (string);
+	  xstring = gnu_readline ("");
+
+	  if (xstring && *xstring)
+	    maybe_save_history (xstring);
 	}
       else
-	string = args(0).string_value ();
+	{
+	  xstring_str = args(0).string_value ();
+	  xstring = xstring_str.c_str ();
+	}
 
       tmp_file = octave_tmp_file_name ();
 
@@ -1383,13 +1403,13 @@
       tmp_file_open = 1;
       unlink (tmp_file);
 
-      if (! string)
+      if (! xstring)
 	{
 	  error ("%s: no string to scan", type); 
 	  return retval;
 	}
 
-      int success = fputs (string, fptr);
+      int success = fputs (xstring, fptr);
       fflush (fptr);
       rewind (fptr);
 
@@ -1579,9 +1599,11 @@
   // Get type and number of bytes per element to read.
 
   const char *prec = "uchar";
+  string tstr;
   if (nargin > 2)
     {
-      prec = args(2).string_value ();
+      tstr = args(2).string_value ();
+      prec = tstr.c_str ();
 
       if (error_state)
 	{
@@ -1766,9 +1788,11 @@
   // Get type and number of bytes per element to read.
 
   const char *prec = "uchar";
+  string tstr;
   if (nargin > 2)
     {
-      prec = args(2).string_value ();
+      tstr = args(2).string_value ();
+      prec = tstr.c_str ();
 
       if (error_state)
 	{
@@ -1935,8 +1959,10 @@
       return retval;
     }
 
-  const char *name = args(0).string_value ();
-  const char *mode = args(1).string_value ();
+  string tstr1 = args(0).string_value ();
+  const char *name = tstr1.c_str ();
+  string tstr2 = args(1).string_value ();
+  const char *mode = tstr2.c_str ();
 
   if (mode[1] || (mode[0] != 'w' && mode[0] != 'r'))
     {
@@ -2058,7 +2084,8 @@
       return retval;
     }
 
-  const char *name = args(0).string_value ();
+  string tstr = args(0).string_value ();
+  const char *name = tstr.c_str ();
 
   if (pipe (stdin_pipe) || pipe (stdout_pipe)) 
     {
@@ -2150,7 +2177,8 @@
       return retval;
     }
 
-  const char *name = args(0).string_value ();
+  string tstr = args(0).string_value ();
+  const char *name = tstr.c_str ();
 
   retval (0) = (double) system (name);
   return retval;
@@ -2185,7 +2213,8 @@
       return retval;
     }
 
-  const char *name = args(0).string_value ();
+  string tstr = args(0).string_value ();
+  const char *name = tstr.c_str ();
 
   pid = fork ();
 
@@ -2318,7 +2347,8 @@
       return retval;
     }
 
-  const char *name = args(0).string_value ();
+  string tstr = args(0).string_value ();
+  const char *name = tstr.c_str ();
 
   if (! args(1).is_scalar_type ())
     {
@@ -2367,7 +2397,8 @@
       return retval;
     }
 
-  const char *name = args(0).string_value ();
+  string tstr = args(0).string_value ();
+  const char *name = tstr.c_str ();
 
   retval (0) = (double) unlink (name);
 
@@ -2454,7 +2485,8 @@
 
   if (args.length () == 1)
     {
-      const char *name = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *name = tstr.c_str ();
 
       static char *fname = 0;
 
@@ -2489,7 +2521,8 @@
 
   if (args.length () == 1)
     {
-      const char *name = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *name = tstr.c_str ();
 
       static char *fname = 0;
 
--- a/src/fsolve.cc
+++ b/src/fsolve.cc
@@ -25,6 +25,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include <strstream.h>
 
 #include "NLEqn.h"
@@ -299,7 +301,8 @@
     }
   else if (nargin == 1 || nargin == 2)
     {
-      const char *keyword = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *keyword = tstr.c_str ();
 
       if (! error_state)
 	{
--- a/src/input.cc
+++ b/src/input.cc
@@ -44,6 +44,8 @@
 #include <cassert>
 #include <csignal>
 
+#include <string>
+
 #include <iostream.h>
 #include <strstream.h>
 
@@ -1008,9 +1010,11 @@
     read_as_string++;
 
   const char *prompt = "debug> ";
+  string tstr;
   if (nargin > 0)
    {
-     prompt = args(0).string_value ();
+     tstr = args(0).string_value ();
+     prompt = tstr.c_str ();
 
      if (error_state)
        {
--- a/src/load-save.cc
+++ b/src/load-save.cc
@@ -30,6 +30,8 @@
 #include <cstring>
 #include <cctype>
 
+#include <string>
+
 #include <iostream.h>
 #include <fstream.h>
 #include <strstream.h>
@@ -2512,9 +2514,9 @@
 	{
 	  FOUR_BYTE_INT len = chm.cols ();
 	  os.write (&len, 4);
-	  const char *tmp = chm.row_as_string (i);
+	  string tstr = chm.row_as_string (i);
+	  const char *tmp = tstr.data ();
 	  os.write (tmp, len);
-	  delete [] tmp;
 	}
     }
   else if (tc.is_range ())
@@ -2819,9 +2821,9 @@
 	{
 	  int len = chm.cols ();
 	  os << "# length: " << len << "\n";
-	  char *tmp = chm.row_as_string (i);
+	  string tstr = chm.row_as_string (i);
+	  char *tmp = tstr.data ();
 	  os.write (tmp, len);
-	  delete [] tmp;
 	  os << "\n";
 	}
     }
--- a/src/lsode.cc
+++ b/src/lsode.cc
@@ -25,6 +25,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include <strstream.h>
 
 #include "ODE.h"
@@ -314,7 +316,8 @@
     }
   else if (nargin == 1 || nargin == 2)
     {
-      const char *keyword = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *keyword = tstr.c_str ();
 
       if (! error_state)
 	{
--- a/src/npsol.cc
+++ b/src/npsol.cc
@@ -25,6 +25,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include <strstream.h>
 
 #include "NPSOL.h"
@@ -801,7 +803,8 @@
     }
   else if (nargin == 1 || nargin == 2)
     {
-      const char *keyword = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *keyword = tstr.c_str ();
 
       if (! error_state)
 	{
--- a/src/pr-output.cc
+++ b/src/pr-output.cc
@@ -29,6 +29,8 @@
 #include <cmath>
 #include <cstring>
 
+#include <string>
+
 #include <iostream.h>
 #include <strstream.h>
 
@@ -1515,7 +1517,8 @@
 
       for (int i = 0; i < nstr; i++)
 	{
-	  char *row = chm.row_as_string (i);
+	  string tstr = chm.row_as_string (i);
+	  const char *row = tstr.c_str ();
 
 	  if (pr_as_read_syntax)
 	    {
--- a/src/pt-const.cc
+++ b/src/pt-const.cc
@@ -32,6 +32,8 @@
 #include <cctype>
 #include <cstring>
 
+#include <string>
+
 #include <fstream.h>
 #include <iostream.h>
 #include <strstream.h>
@@ -1448,16 +1450,17 @@
     }
 }
 
-const char *
+string
 TC_REP::string_value (void) const
 {
+  string retval;
+
   if (type_tag == char_matrix_constant_str)
-    return char_matrix->row_as_string (0);  // XXX FIXME??? XXX
+    retval = char_matrix->row_as_string (0);  // XXX FIXME??? XXX
   else
-    {
-      gripe_invalid_conversion (type_as_string (), "string");
-      return 0;
-    }
+    gripe_invalid_conversion (type_as_string (), "string");
+
+  return retval;
 }
 
 Range
--- a/src/pt-const.h
+++ b/src/pt-const.h
@@ -30,6 +30,8 @@
 
 #include <cstdlib>
 
+#include <string>
+
 #include <iostream.h>
 
 #include "Range.h"
@@ -215,7 +217,7 @@
 	ComplexMatrix complex_matrix_value (int frc_str_conv = 0) const;
 	charMatrix char_matrix_value (int frc_str_conv = 0) const;
 	charMatrix all_strings (void) const;
-	const char *string_value (void) const;
+        string string_value (void) const;
 	Range range_value (void) const;
 	Octave_map map_value (void) const;
 
@@ -546,7 +548,7 @@
   charMatrix all_strings (void) const
     { return rep->all_strings (); }
 
-  const char *string_value (void) const
+  string string_value (void) const
     { return rep->string_value (); }
 
   Range range_value (void) const
--- a/src/pt-plot.cc
+++ b/src/pt-plot.cc
@@ -31,6 +31,8 @@
 
 #include <cstring>
 
+#include <string>
+
 #include <fstream.h>
 #include <iostream.h>
 #include <strstream.h>
@@ -731,7 +733,9 @@
 
 	      int n_max = 0;
 
-	      file = tilde_expand (data.string_value ());
+	      string tstr = data.string_value ();
+
+	      file = tilde_expand (tstr.c_str ());
 	      ifstream ftmp (file);
 	      if (ftmp)
 		{
--- a/src/qpsol.cc
+++ b/src/qpsol.cc
@@ -25,6 +25,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include <strstream.h>
 
 #include "QPSOL.h"
@@ -416,7 +418,8 @@
     }
   else if (nargin == 1 || nargin == 2)
     {
-      const char *keyword = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *keyword = tstr.c_str ();
 
       if (! error_state)
 	{
--- a/src/quad.cc
+++ b/src/quad.cc
@@ -25,6 +25,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include <strstream.h>
 
 #include "Quad.h"
@@ -371,7 +373,8 @@
     }
   else if (nargin == 1 || nargin == 2)
     {
-      const char *keyword = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *keyword = tstr.c_str ();
 
       if (! error_state)
 	{
--- a/src/rand.cc
+++ b/src/rand.cc
@@ -27,6 +27,8 @@
 
 #include <ctime>
 
+#include <string>
+
 #include "f77-uscore.h"
 
 #include "defun-dld.h"
@@ -169,7 +171,8 @@
 
       if (tmp.is_string ())
 	{
-	  const char *s_arg = tmp.string_value ();
+	  string tstr = tmp.string_value ();
+	  const char *s_arg = tstr.c_str ();
 
 	  if (strcmp (s_arg, "dist") == 0)
 	    {
@@ -255,13 +258,17 @@
     }
   else if (nargin == 2)
     {
-      if (args(0).is_string ()
-	  && strcmp (args(0).string_value (), "seed") == 0)
+      if (args(0).is_string ())
 	{
-	  double d = args(1).double_value ();
+	  string tstr = args(0).string_value ();
 
-	  if (! error_state)
-	    set_rand_seed (d);
+	  if (strcmp (tstr.c_str (), "seed") == 0)
+	    {
+	      double d = args(1).double_value ();
+
+	      if (! error_state)
+		set_rand_seed (d);
+	    }
 	}
       else
 	{
--- a/src/schur.cc
+++ b/src/schur.cc
@@ -25,6 +25,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include "CmplxSCHUR.h"
 #include "dbleSCHUR.h"
 
@@ -62,9 +64,12 @@
   tree_constant arg = args(0);
 
   const char *ord = "U";
+  string tstr;
+
   if (nargin == 2)
     {
-      ord = args(1).string_value ();
+      tstr = args(1).string_value (); 
+      ord = tstr.c_str ();
 
       if (error_state)
 	{
--- a/src/sysdep.cc
+++ b/src/sysdep.cc
@@ -40,6 +40,8 @@
 #include <cstdlib>
 #include <cstring>
 
+#include <string>
+
 #ifdef HAVE_UNISTD_H
 #include <sys/types.h>
 #include <unistd.h>
@@ -541,7 +543,8 @@
 
   if (nargin == 1)
     {
-      const char *name = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *name = tstr.c_str ();
 
       if (! error_state)
 	{
@@ -567,11 +570,13 @@
 
   if (nargin == 2)
     {
-      const char *var = args(0).string_value (); 
+      string tstr1 = args(0).string_value (); 
+      const char *var = tstr1.c_str ();
 
       if (! error_state)
 	{
-	  const char *val = args(1).string_value (); 
+	  string tstr2 = args(1).string_value (); 
+	  const char *val = tstr2.c_str ();
 
 	  if (! error_state)
 	    oct_putenv (var, val);
--- a/src/timefns.cc
+++ b/src/timefns.cc
@@ -25,6 +25,8 @@
 #include <config.h>
 #endif
 
+#include <string>
+
 #include "defun.h"
 #include "help.h"
 #include "oct-map.h"
@@ -80,7 +82,8 @@
   tm.tm_yday = NINT (m ["yday"] . double_value ());
   tm.tm_isdst = NINT (m ["isdst"] . double_value ());
 #ifdef HAVE_TMZONE
-  tm.tm_zone = (m ["zone"] . string_value ());
+  string tstr = m ["zone"] . string_value ();
+  tm.tm_zone = tstr.c_str ();
 #endif
 
   return &tm;
@@ -272,7 +275,8 @@
 
   if (args.length () == 2 && args(0).is_string () && args(1).is_map ()) 
     {
-      const char *fmt = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *fmt = tstr.c_str ();
       Octave_map map = args(1).map_value ();
 
       double fraction;
--- a/src/toplev.cc
+++ b/src/toplev.cc
@@ -32,6 +32,8 @@
 #include <cstring>
 #include <ctime>
 
+#include <string>
+
 #include <fstream.h>
 #include <iostream.h>
 #include <strstream.h>
@@ -231,7 +233,8 @@
 
   if (nargin == 1)
     {
-      const char *file = args(0).string_value ();
+      string tstr = args(0).string_value ();
+      const char *file = tstr.c_str ();
 
       if (! error_state)
 	{
@@ -491,7 +494,8 @@
 static Octave_object
 eval_string (const tree_constant& arg, int& parse_status, int nargout)
 {
-  const char *string = arg.string_value ();
+  string tstr = arg.string_value ();
+  const char *string = tstr.c_str ();
 
   if (error_state)
     {
@@ -569,7 +573,8 @@
 
   tree_constant tc_command = args(0);
 
-  const char *tmp_str = tc_command.string_value ();
+  string tstr = tc_command.string_value ();
+  const char *tmp_str = tstr.c_str ();
 
   if (error_state)
     {
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -29,6 +29,8 @@
 #include <csetjmp>
 #include <cstring>
 
+#include <string>
+
 #include <fstream.h>
 #include <iostream.h>
 #include <strstream.h>
@@ -522,7 +524,10 @@
       argv = new char * [n + 1];
       argv[0] = strsave (fcn_name);
       for (int i = 0; i < n; i++)
-	argv[i+1] = strsave (args(i).string_value ());
+	{
+	  string tstr = args(i).string_value ();
+	  argv[i+1] = strsave (tstr.c_str ());
+	}
     }
   else
     error ("%s: expecting all arguments to be strings", fcn_name);
@@ -798,7 +803,8 @@
 
   if (nargin == 1 && args(0).is_string ())
     {
-      char *str = undo_string_escapes (args(0).string_value ());
+      string tstr = args(0).string_value ();
+      char *str = undo_string_escapes (tstr.c_str ());
       retval = str;
       delete [] str;
     }
--- a/src/variables.cc
+++ b/src/variables.cc
@@ -29,6 +29,8 @@
 #include <cstdio>
 #include <cstring>
 
+#include <string>
+
 #include <strstream.h>
 
 #ifdef HAVE_UNISTD_H
@@ -129,8 +131,13 @@
 
   const char *fcn_name = 0;
 
+  string tstr;
+
   if (arg.is_string ())
-    fcn_name = arg.string_value ();
+    {
+      tstr = arg.string_value ();
+      fcn_name = tstr.c_str ();
+    }
 
   if (! fcn_name || error_state)
     {
@@ -171,7 +178,8 @@
       return retval;
     }
 
-  const char *name = args(0).string_value ();
+  string tstr = args(0).string_value ();
+  const char *name = tstr.c_str ();
 
   if (error_state)
     {
@@ -207,7 +215,8 @@
       return retval;
     }
 
-  char *name = strsave (args(0).string_value ());
+  string tstr = args(0).string_value ();
+  char *name = strsave (tstr.c_str ());
 
   if (error_state)
     {
@@ -928,7 +937,8 @@
 
       if (! error_state && val.is_string ())
 	{
-	  const char *s = val.string_value ();
+	  string tstr = val.string_value ();
+	  const char *s = tstr.c_str ();
 
 	  if (s)
 	    retval = strsave (s);