From owner-octave-sources at bevo dot che dot wisc dot edu  Mon Mar 10 18:18:05 1997
Subject: New 'edit' command for Octave
From: Craig Earls <cpearls at ziplink dot net>
To: octave-sources at bevo dot che dot wisc dot edu
Date: Mon, 10 Mar 1997 19:12:56 -0500

This is a multi-part message in MIME format.

--------------3A4E1C4C30F912F07CC70F9E
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Attached are dropin replacements for help.cc and help.h in the octave
src tree. They add a command to invoke your favorite editor on user
compiled functions, syntax:

Octave> edit foo1 foo2 foo3

The editor named in built-in variable EDITOR is called on each function.
If you have XEmacs and gnuserve set up:

Octave> EDITOR="gnuclient -q"
Octave> edit foo1 foo2 ...

will open a new XEmacs frame on each function ready for you to edit. You
do not need to specify a path, Octave will find it for you.

You can only use this by retrieving the Octave 2.0.5 source tree (or a
patched version) and replacing help.cc and help.h with the attached
files (you must rename them to help.cc and help .h)  Help information is
built-in just type 'help edit'.

Comments are always welcome.
-- 
-----------------------------------------------------------------
Craig P Earls				      cpearls at ziplink dot net
LT US Navy, MIT Ocean Engineering	      cpearls at mit dot edu
-----------------------------------------------------------------

--------------3A4E1C4C30F912F07CC70F9E
Content-Type: text/plain; charset=us-ascii; name="help.edit.h"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline; filename="help.edit.h"

/*

Copyright (C) 1996 John W. Eaton

This file is part of Octave.

Octave is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

Octave is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#if !defined (octave_help_h)
#define octave_help_h 1

class ostrstream;

#include <string>

class string_vector;

// XXX FIXME XXX -- should probably use string, not char*.

struct help_list
{
  char *name;
  char *help;
};

extern string_vector names (help_list *l, int& count);
extern help_list *operator_help (void);
extern help_list *keyword_help (void);

extern void print_usage (const string& nm, int just_usage = 0);

extern int help_from_list (ostrstream& output_buf,
			   const help_list *list, const string& nm,
			   int usage);

// Name of the info file specified on command line.
// (--info-file file)
extern string Vinfo_file;

// Name of the info reader we'd like to use.
// (--info-program program)
extern string Vinfo_prog;

// Name of the editor we would like to fire up
extern string Veditor;

extern void symbols_of_help (void);

#endif

/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/

--------------3A4E1C4C30F912F07CC70F9E
Content-Type: text/plain; charset=us-ascii; name="help.edit.cc"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline; filename="help.edit.cc"

/*

Copyright (C) 1996 John W. Eaton

This file is part of Octave.

Octave is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option) any
later version.

Octave is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License
along with Octave; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <csignal>
#include <cstdlib>
#include <cstring>

#include <string>

#include <iostream.h>
#include <fstream.h>
#include <strstream.h>

#ifdef HAVE_UNISTD_H
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <unistd.h>
#endif

#include "str-vec.h"

#include <defaults.h>
#include "defun.h"
#include "dirfns.h"
#include "error.h"
#include "fn-cache.h"
#include "gripes.h"
#include "help.h"
#include "input.h"
#include "oct-obj.h"
#include "pager.h"
#include "pathsearch.h"
#include "pt-const.h"
#include "pt-exp.h"
#include "pt-pr-code.h"
#include "sighandlers.h"
#include "symtab.h"
#include "syswait.h"
#include "toplev.h"
#include "unwind-prot.h"
#include "utils.h"
#include "variables.h"

// Name of the info file specified on command line.
// (--info-file file)
string Vinfo_file;

// Name of the info reader we'd like to use.
// (--info-program program)
string Vinfo_prog;

// If TRUE, don't print additional help message in help and usage
// functions.
static bool Vsuppress_verbose_help_message;

static help_list operators[] =
{
  { "!",
    "Logical not operator.  See also `~'.\n", },

  { "!=",
    "Logical not equals operator.  See also `~' and `<>'.\n", },

  { "\"",
    "String delimiter.\n", },

  { "#",
    "Begin comment character.  See also `%'.", },

  { "%",
    "Begin comment charcter.  See also `#'.", },

  { "&",
    "Logical and operator.  See also `&&'.", },

  { "&&",
    "Logical and operator.  See also `&'.", },

  { "'",
    "Matrix transpose operator.  For complex matrices, computes the\n\
complex conjugate (Hermitian) transpose.  See also `.''\n\
\n\
The single quote character may also be used to delimit strings, but\n\
it is better to use the double quote character, since that is never\n\
ambiguous", },

  { "(",
    "Array index or function argument delimiter.", },

  { ")",
    "Array index or function argument delimiter.", },

  { "*",
    "Multiplication operator.  See also `.*'", },

  { "**",
    "Power operator.  See also `^', `.**', and `.^'", },

  { "+",
    "Addition operator.", },

  { "++",
    "Increment operator.  As in C, may be applied as a prefix or postfix operator.", },

  { ",",
    "Array index, function argument, or command separator.", },

  { "-",
    "Subtraction or unary negation operator.", },

  { "--",
    "Decrement operator.  As in C, may be applied as a prefix or postfix operator.", },

  { ".'",
    "Matrix transpose operator.  For complex matrices, computes the\n\
transpose, *not* the complex conjugate transpose.  See also `''.", },

  { ".*",
    "Element by element multiplication operator.  See also `*'.", },

  { ".**",
    "Element by element power operator.  See also `**', `^', and `.^'.", },

  { "./",
    "Element by element division operator.  See also `/' and `\\'.", },

  { ".^",
    "Element by element power operator.  See also `**', `^', and `.^'.", },

  { "/",
    "Right division.  See also `\\' and `./'.", },

  { ":",
    "Select entire rows or columns of matrices.", },

  { ";",
    "Array row or command separator.  See also `,'.", },

  { "<",
    "Less than operator.", },

  { "<=",
    "Less than or equals operator.", },

  { "<>",
    "Logical not equals operator.  See also `!=' and `~='.", },

  { "=",
    "Assignment operator.", },

  { "==",
    "Equality test operator.", },

  { ">",
    "Greater than operator.", },

  { ">=",
    "Greater than or equals operator.", },

  { "[",
    "Return list delimiter.  See also `]'.", },

  { "\\",
    "Left division operator.  See also `/' and `./'.", },

  { "]",
    "Return list delimiter.  See also `['.", },

  { "^",
    "Power operator.  See also `**', `.^', and `.**.'", },

  { "|",
    "Logical or operator.  See also `||'.", },

  { "||",
    "Logical or operator.  See also `|'.", },

  { "~",
    "Logical not operator.  See also `!' and `~'.", },

  { "~=",
    "Logical not equals operator.  See also `<>' and `!='.", },

  { 0, 0, },
};

static help_list keywords[] =
{
  { "all_va_args",
    "Pass all unnamed arguments to another function call.", },

  { "break",
    "Exit the innermost enclosing while or for loop.", },

  { "catch",
    "begin the cleanup part of a try-catch block", },

  { "continue",
    "Jump to the end of the innermost enclosing while or for loop.", },

  { "else",
    "Alternate action for an if block.", },

  { "elseif",
    "Alternate conditional test for an if block.", },

  { "end",
    "Mark the end of any for, if, while, or function block.", },

  { "end_try_catch",
    "Mark the end of an try-catch block.", }, 

  { "end_unwind_protect",
    "Mark the end of an unwind_protect block.", }, 

  { "endfor",
    "Mark the end of a for loop.", },

  { "endfunction",
    "Mark the end of a function.", },

  { "endif",
    "Mark the end of an if block.", },

  { "endwhile",
    "Mark the end of a while loop.", },

  { "for",
    "Begin a for loop.", },

  { "function",
    "Begin a function body.", },

  { "global",
    "Declare variables to have global scope.", },

  { "gplot",
    "Produce 2-D plots using gnuplot-like command syntax.", },

  { "gsplot",
    "Produce 3-D plots using gnuplot-like command syntax.", },

  { "if",
    "Begin an if block.", },

  { "return",
    "Return from a function.", },

  { "try",
    "Begin a try-catch block.", }, 

  { "unwind_protect",
    "Begin an unwind_protect block.", }, 

  { "unwind_protect_cleanup",
    "Begin the cleanup section of an unwind_protect block.", }, 

  { "while",
    "Begin a while loop.", },

  { 0, 0, },
};

// Return a copy of the operator or keyword names.

string_vector
names (help_list *lst, int& count)
{
  string_vector retval;

  count = 0;
  help_list *ptr = lst;
  while (ptr->name)
    {
      count++;
      ptr++;
    }

  if (count > 0)
    {
      retval.resize (count);

      ptr = lst;
      for (int i = 0; i < count; i++)
	{
	  retval[i] = ptr->name;
	  ptr++;
	}
    }

  return retval;
}

help_list *
operator_help (void)
{
  return operators;
}

help_list *
keyword_help (void)
{
  return keywords;
}

#if defined (USE_GNU_INFO)
static void
additional_help_message (ostream& os)
{
  if (! Vsuppress_verbose_help_message)
    os << "\n\
Additional help for builtin functions, operators, and variables\n\
is available in the on-line version of the manual.\n\
\n\
Use the command `help -i <topic>' to search the manual index.\n";
}
#else
static void
additional_help_message (ostream&)
{
}
#endif

void
print_usage (const string& nm, int just_usage)
{
  symbol_record *sym_rec = global_sym_tab->lookup (nm, 0, 0);
  if (sym_rec)
    {
      string h = sym_rec->help ();

      if (h.length () > 0)
	{
	  octave_stdout << "\n*** " << nm << ":\n\n"
	    << h << "\n";

	  if (! just_usage)
	    additional_help_message (octave_stdout);
	}
    }
  else
    warning ("no usage message found for `%s'", nm.c_str ());
}

static void
display_names_from_help_list (ostream& os, help_list *list,
			      const char *desc)
{
  int count = 0;
  string_vector symbols = names (list, count);
  if (! symbols.empty ())
    {
      os << "\n*** " << desc << ":\n\n";
      symbols.list_in_columns (os);
    }
}

static string
print_symbol_type (ostream& os, symbol_record *sym_rec,
		   const string& name, int print)
{
  string retval;

  if (sym_rec->is_user_function ())
    {
      tree_fvc *defn = sym_rec->def ();

      string fn = defn->fcn_file_name ();

      if (! fn.empty ())
	{
	  string ff = fcn_file_in_path (fn);

	  ff = ff.length () > 0 ? ff : fn;

	  if (print)
	    os << name
	       << " is the function defined from:\n"
	       << ff << "\n";
	  else
	    retval = ff;
	}
      else
	{
	  if (print)
	    os << name << " is a user-defined function\n";
	  else
	    retval = "user-defined function";
	}
    }
  else if (sym_rec->is_text_function ())
    {
      if (print)
	os << name << " is a builtin text-function\n";
      else
	retval = "builtin text-function";
    }
  else if (sym_rec->is_builtin_function ())
    {
      if (print)
	os << name << " is a builtin function\n";
      else
	retval = "builtin function";
    }
  else if (sym_rec->is_user_variable ())
    {
      if (print)
	os << name << " is a user-defined variable\n";
      else
	retval = "user-defined variable";
    }
  else if (sym_rec->is_builtin_variable ())
    {
      if (print)
	os << name << " is a builtin variable\n";
      else
	retval = "builtin variable";
    }
  else
    {
      if (print)
	os << "which: `" << name << "' has unknown type\n";
      else
	retval = "unknown type";
    }

  return retval;
}

static void
display_symtab_names (ostream& os, const string_vector& names,
		      int /* count */, const string& desc)
{
  if (! names.empty ())
    {
      os << "\n*** " << desc << ":\n\n";
      names.list_in_columns (os);
    }
}

static void
simple_help (void)
{
  display_names_from_help_list (octave_stdout, operator_help (),
				"operators");

  display_names_from_help_list (octave_stdout, keyword_help (),
				"reserved words");

#ifdef LIST_SYMBOLS
#undef LIST_SYMBOLS
#endif
#define LIST_SYMBOLS(type, msg) \
  do \
    { \
      int count; \
      string_vector names = global_sym_tab->list (count, 0, 0, 1, type); \
      display_symtab_names (octave_stdout, names, count, msg); \
    } \
  while (0)

  // XXX FIXME XXX -- is this distinction needed?

  LIST_SYMBOLS (symbol_def::TEXT_FUNCTION,
		"text functions (these names are also reserved)");

  LIST_SYMBOLS (symbol_def::MAPPER_FUNCTION, "mapper functions");

  LIST_SYMBOLS (symbol_def::BUILTIN_FUNCTION, "general functions");

  LIST_SYMBOLS (symbol_def::BUILTIN_VARIABLE, "builtin variables");

  // Also need to list variables and currently compiled functions from
  // the symbol table, if there are any.

  // Also need to search octave_path for script files.

  dir_path p (Vload_path);

  string_vector dirs = p.all_directories ();

  int len = dirs.length ();

  for (int i = 0; i < len; i++)
    {
      string_vector names = octave_fcn_file_name_cache::list (dirs[i]);

      if (! names.empty ())
	{
	  octave_stdout << "\n*** function files in "
			<< make_absolute (dirs[i], Vcurrent_directory)
			<< ":\n\n";

	  names.list_in_columns (octave_stdout);
	}
    }

  additional_help_message (octave_stdout);
}

#if defined (USE_GNU_INFO)
static int
try_info (const string& nm)
{
  int status = 0;

  static char *cmd_str = 0;

  delete [] cmd_str;
  cmd_str = 0;

  ostrstream cmd_buf;

  cmd_buf << Vinfo_prog << " --file " << Vinfo_file;

  string directory_name = Vinfo_file;
  size_t pos = directory_name.rfind ('/');

  if (pos != NPOS)
    {
      directory_name.resize (pos + 1);
      cmd_buf << " --directory " << directory_name;
    }

  if (nm.length () > 0)
    cmd_buf << " --index-search " << nm;

  cmd_buf << ends;

  cmd_str = cmd_buf.str ();

  volatile octave_interrupt_handler old_interrupt_handler
    = octave_ignore_interrupts ();

  status = system (cmd_str);

  octave_set_interrupt_handler (old_interrupt_handler);

  if (WIFEXITED (status))
    status = WEXITSTATUS (status);
  else
    status = 127;

  return status;
}

static void
help_from_info (const string_vector& argv, int idx, int argc)
{
  if (idx == argc)
    try_info (string ());
  else
    {
      for (int i = idx; i < argc; i++)
	{
	  int status = try_info (argv[i]);

	  if (status)
	    {
	      if (status < 0)
		{
		  message ("help",
			   "sorry, `%s' is not indexed in the manual",
			   argv[i].c_str ());
		  sleep (2);
		}
	      else
		{
		  error ("help: unable to find info!");
		  break;
		}
	    }
	}
    }
}
#else
static void
help_from_info (const string_vector&, int, int)
{
  message (0, "sorry, help -i is not available in this version of Octave");
}
#endif

int
help_from_list (ostream& os, const help_list *list,
		const string& nm, int usage)
{
  char *name;
  while ((name = list->name) != 0)
    {
      if (strcmp (name, nm.c_str ()) == 0)
	{
	  if (usage)
	    os << "\nusage: ";
	  else
	    {
	      os << "\n*** " << nm << ":\n\n";
	    }

	  os << list->help << "\n";

	  return 1;
	}
      list++;
    }
  return 0;
}

static void
builtin_help (int argc, const string_vector& argv)
{
  help_list *op_help_list = operator_help ();
  help_list *kw_help_list = keyword_help ();

  for (int i = 1; i < argc; i++)
    {
      if (help_from_list (octave_stdout, op_help_list, argv[i], 0))
	continue;

      if (help_from_list (octave_stdout, kw_help_list, argv[i], 0))
	continue;

      symbol_record *sym_rec = lookup_by_name (argv[i], 0);

      if (sym_rec && sym_rec->is_defined ())
	{
	  string h = sym_rec->help ();

	  if (h.length () > 0)
	    {
	      print_symbol_type (octave_stdout, sym_rec, argv[i], 1);
	      octave_stdout << "\n" << h << "\n";
	      continue;
	    }
	}

      string path = fcn_file_in_path (argv[i]);

      string h = get_help_from_file (path);

      if (! h.empty ())
	{
	  octave_stdout << argv[i] << " is the file:\n"
	    << path << "\n\n" << h << "\n";

	  continue;
	}

      octave_stdout << "\nhelp: sorry, `" << argv[i]
		    << "' is not documented\n"; 
    }

  additional_help_message (octave_stdout);
}

#if defined (USE_GNU_INFO)
DEFUN_TEXT (help, args, ,
  "help [-i] [topic ...]\n\
\n\
print cryptic yet witty messages")
#else
DEFUN_TEXT (help, args, ,
  "help [topic ...]\n\
\n\
print cryptic yet witty messages")
#endif
{
  octave_value_list retval;

  int argc = args.length () + 1;

  string_vector argv = args.make_argv ("help");

  if (error_state)
    return retval;

  if (argc == 1)
    {
      simple_help ();
    }
  else
    {
      if (argv[1] == "-i")
	{
	  help_from_info (argv, 2, argc);
	}
      else
	{
	  builtin_help (argc, argv);
	}
    }

  return retval;
}

DEFUN_TEXT (type, args, nargout,
  "type NAME ...]\n\
\n\
display the definition of each NAME that refers to a function")
{
  octave_value_list retval;

  begin_unwind_frame ("Ftype");

  int argc = args.length () + 1;

  string_vector argv = args.make_argv ("type");

  if (error_state)
    return retval;

  if (argc > 1)
    {
      // XXX FIXME XXX -- we should really use getopt ()

      bool quiet = false;
      bool pr_orig_txt = true;

      int idx;

      for (idx = 1; idx < argc; idx++)
	{
	  if (argv[idx] == "-q" || argv[idx] == "-quiet")
	    quiet = true;
	  else if (argv[idx] == "-t" || argv[idx] == "-transformed")
	    pr_orig_txt = false;
	  else
	    break;
	}

      if (idx == argc)
	{
	  print_usage ("type");
	  return retval;
	}

      ostrstream output_buf;

      for (int i = idx; i < argc; i++)
	{
	  string id = argv[i];
	  string elts;

	  if (id[id.length () - 1] != '.')
	    {
	      size_t pos = id.find ('.');

	      if (pos != NPOS)
		{
		  elts = id.substr (pos+1);
		  id = id.substr (0, pos);
		}
	    }

	  symbol_record *sym_rec = lookup_by_name (id, 0);

	  if (sym_rec)
	    {
	      if (sym_rec->is_user_function ())
		{
		  tree_fvc *defn = sym_rec->def ();

		  string fn = defn->fcn_file_name ();
		  string ff = fcn_file_in_path (fn);

		  if (pr_orig_txt && ! ff.empty ())
		    {
		      ifstream fs (ff.c_str (), ios::in);

		      if (fs)
			{
			  if (nargout == 0 && ! quiet)
			    output_buf << argv[i]
				       << " is the function defined from:\n"
				       << ff << "\n\n";

			  char ch;

			  while (fs.get (ch))
			    output_buf << ch;
			}
		      else
			output_buf << "unable to open `" << ff
				   << "' for reading!\n";
		    }
		  else
		    {
		      if (nargout == 0 && ! quiet)
			output_buf << argv[i]
				   << " is a user-defined function:\n\n";

		      tree_print_code tpc (output_buf, "", pr_orig_txt);

		      defn->accept (tpc);
		    }
		}

	      // XXX FIXME XXX -- this code should be shared with
	      // Fwhich.

	      else if (sym_rec->is_text_function ())
		output_buf << argv[i] << " is a builtin text-function\n";
	      else if (sym_rec->is_builtin_function ())
		output_buf << argv[i] << " is a builtin function\n";
	      else if (sym_rec->is_user_variable ()
		       || sym_rec->is_builtin_variable ())
		{
		  tree_fvc *defn = sym_rec->def ();

		  assert (defn && defn->is_constant ());

		  tree_constant *tmp = (tree_constant *) defn;

		  int var_ok = 1;
		  if (tmp && tmp->is_map ())
		    {
		      if (! elts.empty ())
			{
			  octave_value ult =
			    tmp->lookup_map_element (elts, 0, 1);

			  if (! ult.is_defined ())
			    var_ok = 0;			    
			}
		    }

		  if (nargout == 0 && ! quiet)
		    {
		      if (var_ok)
			{
			  output_buf << argv[i];
			  if (sym_rec->is_user_variable ())
			    output_buf << " is a user-defined variable\n";
			  else
			    output_buf << " is a built-in variable\n";
			}
		      else
			{
			  if (! elts.empty ())
			    output_buf << "type: structure `" << id
			      << "' has no member `" << elts << "'\n";
			  else
			    output_buf << "type: `" << id
			      << "' has unknown type!\n";
			}
		    }
		  if (! tmp->is_map ())
		    {
		      tree_print_code tpc (output_buf, "", pr_orig_txt);

		      tmp->accept (tpc);

		      if (nargout == 0)
			output_buf << "\n";
		    }
		}
	      else
		output_buf << "type: `" << argv[i] << "' has unknown type!\n";
	    }
	  else
	    output_buf << "type: `" << argv[i] << "' undefined\n";
	}

      output_buf << ends;

      char *s = output_buf.str ();

      if (nargout == 0)
	octave_stdout << s;
      else
	retval = s;

      delete [] s;
    }
  else
    print_usage ("type");

  return retval;
}

DEFUN_TEXT (which, args, nargout,
  "which NAME ...\n\
\n\
display the type of each NAME.  If NAME is defined from an function\n\
file, print the full name of the file. Text added as a test.")
{
  octave_value_list retval;

  int argc = args.length () + 1;

  string_vector argv = args.make_argv ("which");

  if (error_state)
    return retval;

  if (argc > 1)
    {
      if (nargout > 0)
	retval.resize (argc-1, Matrix ());

      for (int i = 1; i < argc; i++)
	{
	  symbol_record *sym_rec = lookup_by_name (argv[i], 0);

	  if (sym_rec)
	    {
	      int print = (nargout == 0);
	      string tmp = print_symbol_type (octave_stdout, sym_rec,
					      argv[i], print);
	      if (! print)
		retval(i) = tmp;
	    }
	  else
	    {
	      if (nargout == 0)
		octave_stdout << "which: `" << argv[i] << "' is undefined\n";
	      else
		retval(i) = "undefined";
	    }
	}
    }
  else
    print_usage ("which");

  return retval;
}

// Added 10 Mar 1997 by Craig P. Earls

DEFUN_TEXT (edit, args, nargout,
            "edit NAME ...\n\
\n\
Invokes the editor named in builtin variable EDITOR on the listed functions.\n\
\n\
The EDITOR variable should hold the shell command used to start up your\n\
editor, if you want to edit asynchronously the shell command should \n\
reflect that. For example:\n\
\n\
EDITOR=\"gnuclient -q\"\n\
\n\
will open a new emacs frame for each function named. If you drop the -q\n\
they will be edited sequentially and control will be passed back to \n\
Octave when all editing is complete.\n")
{
    octave_value_list retval;

    int argc = args.length () + 1;
        
    string_vector argv = args.make_argv ("edit");
        
    if (error_state)
        return retval;
        
    if (argc > 1)
    {
        for (int i = 1; i < argc; i++)
        {
            symbol_record *sym_rec = lookup_by_name (argv[i], 0);
            
            if (sym_rec->is_user_function())
            {
                tree_fvc *defn = sym_rec->def ();
                string fn = defn->fcn_file_name ();

                if (! fn.empty ())
                {
                    string ff = fcn_file_in_path (fn);
                    ff = ff.length () > 0 ? ff : fn;

                    int status=0;
                    static char *cmd_str = 0;
                    delete [] cmd_str;
                    cmd_str = 0;

                    ostrstream cmd_buf;

                    cmd_buf << Veditor << " " << ff <<ends;
                    cmd_str = cmd_buf.str();

                    volatile octave_interrupt_handler old_interrupt_handler
                        = octave_ignore_interrupts ();

                    status = system (cmd_str);
                    
                    octave_set_interrupt_handler (old_interrupt_handler);

                    if (WIFEXITED (status))
                        status = WEXITSTATUS (status);
                    else
                        status = 127;

                     

                };
            }
            
            else
            {
                if (nargout == 0)
                    octave_stdout << "edit: `" << argv[i] << "' is not a user function\n";
                else
                    retval(i) = "undefined";
            }
        }
    }
    else
        print_usage ("edit");
           
    return retval;
}


static int
suppress_verbose_help_message (void)
{
  Vsuppress_verbose_help_message
    = check_preference ("suppress_verbose_help_message");

  return 0;
}

static int
info_file (void)
{
  int status = 0;

  string s = builtin_string_variable ("INFO_FILE");

  if (s.empty ())
    {
      gripe_invalid_value_specified ("INFO_FILE");
      status = -1;
    }
  else
    Vinfo_file = s;

  return status;
}

static int
info_prog (void)
{
  int status = 0;

  string s = builtin_string_variable ("INFO_PROGRAM");

  if (s.empty ())
    {
      gripe_invalid_value_specified ("INFO_PROGRAM");
      status = -1;
    }
  else
    Vinfo_prog = s;

  return status;
}

void
symbols_of_help (void)
{
  DEFVAR (INFO_FILE, Vinfo_file, 0, info_file,
          "name of the Octave info file");

  DEFVAR (INFO_PROGRAM, Vinfo_prog, 0, info_prog,
          "name of the Octave info reader");

  DEFVAR (suppress_verbose_help_message, 0.0, 0, suppress_verbose_help_message,
          "suppress printing of message pointing to additional help in the\n\
help and usage functions");
}

/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/

--------------3A4E1C4C30F912F07CC70F9E--