dir-ops.h

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////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 1996-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// 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
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////
 
#if ! defined (octave_dir_ops_h)
#define octave_dir_ops_h 1
 
#include "octave-config.h"
 
#include <string>
 
#include "str-vec.h"
 
namespace octave
{
  namespace sys
  {
    class
    OCTAVE_API
    dir_entry
    {
 
      // NOTE: This class cannot be used safely cross-platform (Windows) with
      // non-ASCII characters in paths.
      // Consider replacing the implementation using std::filesystem (C++ 17).
      // In the meantime, consider using octave::sys::get_dirlist instead.
 
    public:
 
      dir_entry (const std::string& n = "")
        : name (n), dir (nullptr), fail (false), errmsg ()
      {
        if (! name.empty ())
          open ();
      }
 
      dir_entry (const dir_entry& d)
        : name (d.name), dir (d.dir), fail (d.fail), errmsg (d.errmsg) { }
 
      dir_entry& operator = (const dir_entry& d)
      {
        if (this != &d)
          {
            name = d.name;
            dir = d.dir;
            fail = d.fail;
            errmsg = d.errmsg;
          }
 
        return *this;
      }
 
      ~dir_entry (void) { close (); }
 
      bool open (const std::string& = "");
 
      string_vector read (void);
 
      bool close (void);
 
      bool ok (void) const { return dir && ! fail; }
 
      operator bool () const { return ok (); }
 
      std::string error (void) const { return ok () ? "" : errmsg; }
 
      static unsigned int max_name_length (void);
 
    private:
 
      // Name of the directory.
      std::string name;
 
      // A pointer to the contents of the directory.  We use void here to
      // avoid possible conflicts with the way some systems declare the
      // type DIR.
      void *dir;
 
      // TRUE means the open for this directory failed.
      bool fail;
 
      // If a failure occurs, this contains the system error text.
      std::string errmsg;
    };
  }
}
 
#endif