update packages

[CreaPhase.git] / octave_packages / m / path / pathdef.m

diff --git a/octave_packages/m/path/pathdef.m b/octave_packages/m/path/pathdef.m
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+## Copyright (C) 2005-2012 Bill Denney
+## Copyright (C) 2007-2009 Ben Abbott
+##
+## 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 3 of the License, 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, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{val} =} pathdef ()
+## Return the default path for Octave.
+## The path information is extracted from one of three sources.
+## In order of preference, those are;
+##
+## @enumerate
+## @item @file{~/.octaverc}
+##
+## @item @file{<octave-home>/@dots{}/<version>/m/startup/octaverc}
+##
+## @item Octave's path prior to changes by any octaverc.
+## @end enumerate
+## @seealso{path, addpath, rmpath, genpath, savepath, pathsep}
+## @end deftypefn
+
+function val = pathdef ()
+
+  ## Locate the site octaverc file.
+  pathdir = octave_config_info ("localstartupfiledir");
+  site_octaverc = fullfile (pathdir, "octaverc");
+
+  ## Locate the user ~\.octaverc file.
+  user_octaverc = fullfile ("~", ".octaverc");
+
+  ## Extract the specified paths from the site and user octaverc"s.
+  site_path = __extractpath__ (site_octaverc);
+  if (exist (user_octaverc, "file"))
+    user_path = __extractpath__ (user_octaverc);
+  else
+    user_path = "";
+  endif
+
+  ## A path definition in the user octaverc has precedence over the
+  ## site.
+
+  if (! isempty (user_path))
+    val = user_path;
+  elseif (! isempty (site_path))
+    val = site_path;
+  else
+    val = __pathorig__ ();
+  endif
+
+endfunction
+
+## Extact the path information from the script/function @var{file},
+## created by @file{savepath.m}.  If @var{file} is omitted,
+## @file{~/.octaverc} is used.  If successful, @code{__extractpath__}
+## returns the path specified in @var{file}.
+
+## Author: Ben Abbott <bpabbott@mac.com>
+
+function specifiedpath = __extractpath__ (savefile)
+
+  ## The majority of this code was borrowed from savepath.m.
+  ## FIXME -- is there some way to share the common parts instead of
+  ## duplicating?
+
+  beginstring = "## Begin savepath auto-created section, do not edit";
+  endstring   = "## End savepath auto-created section";
+
+  if (nargin == 0)
+    savefile = tilde_expand ("~/.octaverc");
+  endif
+
+  ## Parse the file if it exists to see if we should replace a section
+  ## or create a section.
+  startline = 0;
+  endline = 0;
+  filelines = {};
+  if (exist (savefile) == 2)
+    ## read in all lines of the file
+    [fid, msg] = fopen (savefile, "rt");
+    if (fid < 0)
+      error ("__extractpath__: could not open savefile, %s: %s", savefile, msg);
+    endif
+    unwind_protect
+      linenum = 0;
+      while (linenum >= 0)
+        result = fgetl (fid);
+        if (isnumeric (result))
+          ## End at the end of file.
+          linenum = -1;
+        else
+          linenum++;
+          filelines{linenum} = result;
+          ## Find the first and last lines if they exist in the file.
+          if (strcmp (result, beginstring))
+            startline = linenum + 1;
+          elseif (strcmp (result, endstring))
+            endline = linenum - 1;
+          endif
+        endif
+      endwhile
+    unwind_protect_cleanup
+      closeread = fclose (fid);
+      if (closeread < 0)
+        error ("__extractpath__: could not close savefile after reading, %s",
+               savefile);
+      endif
+    end_unwind_protect
+  endif
+
+  ## Extract the path specifiation.
+  if (startline > endline || (startline > 0 && endline == 0))
+    error ("__extractpath__: unable to parse file, %s", savefile);
+  elseif (startline > 0)
+    ## Undo doubling of single quote characters performed by savepath.
+    specifiedpath = strrep (regexprep (cstrcat (filelines(startline:endline){:}),
+                                       " *path *\\('(.*)'\\); *", "$1"),
+                            "''", "'");
+  else
+    specifiedpath = "";
+  endif
+
+endfunction