pathsearch.h

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/*

Copyright (C) 1996-2015 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 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/>.

*/

#if !defined (octave_pathsearch_h)
#define octave_pathsearch_h 1

#include <string>

#include "str-vec.h"

class
OCTAVE_API
dir_path
{
public:

  dir_path (const std::string& s = std::string (),
            const std::string& d = std::string ())
    : p_orig (s), p_default (d), initialized (false), p (), pv ()
  {
    if (! p_orig.empty ())
      init ();
  }

  dir_path (const dir_path& dp)
    : p_orig (dp.p_orig), p_default (dp.p_default),
      initialized (dp.initialized), p (dp.p), pv (dp.pv)
  { }

  dir_path& operator = (const dir_path& dp)
  {
    p_orig = dp.p_orig;
    p_default = dp.p_default;
    initialized = dp.initialized;
    p = dp.p;
    pv = dp.pv;
    return *this;
  }

  ~dir_path (void) { }

  void set (const std::string& s)
  {
    initialized = false;
    p_orig = s;
    init ();
  }

  string_vector elements (void);
  string_vector all_directories (void);

  std::string find_first (const std::string&);
  std::string find (const std::string& nm) { return find_first (nm); }

  string_vector find_all (const std::string&);

  std::string find_first_of (const string_vector& names);
  string_vector find_all_first_of (const string_vector& names);

  void rehash (void)
  {
    initialized = false;
    init ();
  }

  static char path_sep_char (void)
  {
    return static_members::path_sep_char ();
  }

  static void path_sep_char (char c)
  {
    static_members::path_sep_char (c);
  }

  static std::string path_sep_str (void)
  {
    return static_members::path_sep_str ();
  }

  static bool is_path_sep (char c) { return c == path_sep_char (); }

private:

  // The colon separated list that we were given.
  std::string p_orig;

  // The default path.  If specified, replaces leading, trailing, or
  // doubled colons in p_orig.
  std::string p_default;

  // TRUE means we've unpacked p.
  bool initialized;

  // A version of the colon separate list on which we have performed
  // tilde, variable, and possibly default path expansion.
  std::string p;

  // The elements of the list.
  string_vector pv;

  void init (void);

  // Use a singleton class for these data members instead of just
  // making them static members of the dir_path class so that we can
  // ensure proper initialization.

  class OCTAVE_API static_members
  {
  public:

    static_members (void);

    static char path_sep_char (void)
    {
      return instance_ok () ? instance->xpath_sep_char : 0;
    }

    static void path_sep_char (char c)
    {
      if (instance_ok ())
        {
          instance->xpath_sep_char = c;
          instance->xpath_sep_str = std::string (1, c);
        }
    }

    static std::string path_sep_str (void)
    {
      return instance_ok () ? instance->xpath_sep_str : std::string ();
    }

  private:

    static static_members *instance;

    static void cleanup_instance (void) { delete instance; instance = 0; }

    static bool instance_ok (void);

    // No copying!

    static_members (const static_members&);

    static_members& operator = (const static_members&);

    char xpath_sep_char;

    std::string xpath_sep_str;
  };
};

#endif