--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,5 +1,22 @@
+Fri Nov 14 01:53:13 1997  John W. Eaton  <jwe@bevo.che.wisc.edu>
+
+	* lex.l (have_continuation, have_ellipsis_continuation): Declare
+	arg as bool, not int.  Change callers.
+
+	* lex.l (Vbackslash_escapes): New static variable.
+	(backslash_escapes): New function.
+	(do_string_escapes): Return immediately if ! Vbackslash_escapes.
+	(eat_whitespace, eat_continuation): Only call have_continuation if
+	Vbackslash_escapes.
+	(handle_string): Backslash is only special if Vbackslash_escapes.
+	(symbols_of_lex): Add DEFVAR for backslash_escapes.
+	* octave.cc (maximum_braindamage): Set backslash_escapes to 0.
+
 Thu Nov 13 16:20:40 1997  John W. Eaton  <jwe@bevo.che.wisc.edu>
 
+	* variables.cc (Fexist): Also return 2 if NAME is a regular file
+	somewhere in the LOADPATH.
+
 	* data.cc (sumsq): Fix doc string.
 
 	* parse.y (Fsource): Call parse_fcn_file, not parse_and_execute.

--- a/src/defun-int.h
+++ b/src/defun-int.h
@@ -100,7 +100,7 @@
       { \
 	check_version (OCTAVE_VERSION, #name); \
 	install_builtin_function (F ## name, #name, doc); \
-	installed = true;
+	installed = true; \
       } \
     return installed; \
   }

--- a/src/lex.l
+++ b/src/lex.l
@@ -159,6 +159,9 @@
 
 static int Vwhitespace_in_literal_matrix;
 
+// Should Octave treat backslashes in strings as escapes that
+// introduce special characters like newline (\n), tab (\t), etc.?
+static bool Vbackslash_escapes;
 
 // Forward declarations for functions defined at the bottom of this
 // file.
@@ -179,8 +182,8 @@
 static int handle_string (char delim, int text_style = 0);
 static int handle_close_brace (int spc_gobbled);
 static int handle_identifier (const string& tok, int spc_gobbled);
-static bool have_continuation (int trailing_comments_ok = 1);
-static bool have_ellipsis_continuation (int trailing_comments_ok = 1);
+static bool have_continuation (bool trailing_comments_ok = true);
+static bool have_ellipsis_continuation (bool trailing_comments_ok = true);
 static yum_yum eat_whitespace (void);
 static yum_yum eat_continuation (void);
 
@@ -721,6 +724,9 @@
 static void
 do_string_escapes (char *s)
 {
+  if (! Vbackslash_escapes)
+    return;
+
   char *p1 = s;
   char *p2 = s;
 
@@ -1367,7 +1373,7 @@
 	    break;
 	  else
 	    {
-	      if (have_continuation ())
+	      if (Vbackslash_escapes && have_continuation ())
 		break;
 	      else
 		goto done;
@@ -1433,7 +1439,7 @@
 // characters, return 0.  Otherwise, return 1.
 
 static bool
-have_continuation (int trailing_comments_ok)
+have_continuation (bool trailing_comments_ok)
 {
   ostrstream buf;
 
@@ -1472,7 +1478,7 @@
   yyunput (c, yytext);
   return false;
 
- cleanup:
+cleanup:
   buf << ends;
   char *s = buf.str ();
   if (s)
@@ -1482,6 +1488,7 @@
 	yyunput (s[len], yytext);
     }
   delete [] s;
+
   return false;
 }
 
@@ -1490,7 +1497,7 @@
 // line character.
 
 static bool
-have_ellipsis_continuation (int trailing_comments_ok)
+have_ellipsis_continuation (bool trailing_comments_ok)
 {
   char c1 = yyinput ();
   if (c1 == '.')
@@ -1521,7 +1528,7 @@
   int retval = ATE_NOTHING;
   int c = yyinput ();
   if ((c == '.' && have_ellipsis_continuation ())
-      || (c == '\\' && have_continuation ()))
+      || (c == '\\' && Vbackslash_escapes && have_continuation ()))
     retval = eat_whitespace ();
   else
     yyunput (c, yytext);
@@ -1541,7 +1548,7 @@
     {
       current_input_column++;
 
-      if (c == '\\')
+      if (c == '\\' && Vbackslash_escapes)
 	{
 	  if (escape_pending)
 	    {
@@ -1550,7 +1557,7 @@
 	    }
 	  else
 	    {
-	      if (have_continuation (0))
+	      if (have_continuation (false))
 		escape_pending = 0;
 	      else
 		{
@@ -1562,7 +1569,7 @@
 	}
       else if (c == '.')
 	{
-	  if (! have_ellipsis_continuation (0))
+	  if (! have_ellipsis_continuation (false))
 	    buf << (char) c;
 	}
       else if (c == '\n')
@@ -1955,6 +1962,14 @@
 }
 
 int
+backslash_escapes (void)
+{
+  Vbackslash_escapes = check_preference ("backslash_escapes");
+
+  return 0;
+}
+
+int
 whitespace_in_literal_matrix (void)
 {
   int pref = 0;
@@ -1977,6 +1992,10 @@
 void
 symbols_of_lex (void)
 {
+  DEFVAR (backslash_escapes, 1.0, 0, backslash_escapes,
+    "if nonzero, Octave recognizes backslashes in strings as escapes that\n\
+introduce special characters like newline (\\n), tab (\\t), etc.");
+
   DEFVAR (whitespace_in_literal_matrix, "", 0, whitespace_in_literal_matrix,
     "control auto-insertion of commas and semicolons in literal matrices");
 }

--- a/src/octave.cc
+++ b/src/octave.cc
@@ -325,6 +325,7 @@
 {
   bind_builtin_variable ("PS1", ">> ");
   bind_builtin_variable ("PS2", "");
+  bind_builtin_variable ("backslash_escapes", 0.0);
   bind_builtin_variable ("beep_on_error", 1.0);
   bind_builtin_variable ("default_eval_print_flag", 0.0);
   bind_builtin_variable ("default_save_format", "mat-binary");

--- a/src/variables.cc
+++ b/src/variables.cc
@@ -398,7 +398,12 @@
    1 : NAME is a variable\n\
    2 : NAME is a function\n\
    3 : NAME is a .oct file in the current LOADPATH\n\
-   5 : NAME is a built-in function")
+   5 : NAME is a built-in function\n\
+\n\
+This function also returns 2 if a regular file called NAME exists in\n\
+Octave's LOADPATH.  If you want information about other types of\n\
+files, you should use some combination of the functions file_in_path\n\
+and stat instead.")
 {
   octave_value_list retval;
 
@@ -466,10 +471,15 @@
 	    }
 	  else
 	    {
-	      file_stat fs (name);
+	      string file_name = file_in_path (name, "");
 
-	      if (fs && fs.is_reg ())
-		retval = 2.0;
+	      if (! file_name.empty ())
+		{
+		  file_stat fs (file_name);
+
+		  if (fs && fs.is_reg ())
+		    retval = 2.0;
+		}
 	    }
 	}
     }