text: 
  /*
   * uce-dirent.h - operating system independent dirent implementation
   *
   * Copyright (C) 1998-2002  Toni Ronkko
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files (the
   * ``Software''), to deal in the Software without restriction, including
   * without limitation the rights to use, copy, modify, merge, publish,
   * distribute, sublicense, and/or sell copies of the Software, and to
   * permit persons to whom the Software is furnished to do so, subject to
   * the following conditions:
   *
   * The above copyright notice and this permission notice shall be included
   * in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS
   * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   * IN NO EVENT SHALL TONI RONKKO BE LIABLE FOR ANY CLAIM, DAMAGES OR
   * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
   * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
   * OTHER DEALINGS IN THE SOFTWARE.
   *
   *
   * May 28 1998, Toni Ronkko <tronkko@messi.uku.fi>
   *
   * $Id: uce-dirent.h,v 1.7 2002/05/13 10:48:35 tr Exp $
   *
   * $Log: uce-dirent.h,v $
   * Revision 1.7  2002/05/13 10:48:35  tr
   * embedded some source code directly to the header so that no source
   * modules need to be included in the MS Visual C project using the
   * interface, removed all the dependencies to other headers of the `uce'
   * library so that the header can be made public
   *
   * Revision 1.6  2002/04/12 16:22:04  tr
   * Unified Compiling Environment (UCE) replaced `std' library
   *
   * Revision 1.5  2001/07/20 16:33:40  tr
   * moved to `std' library and re-named defines accordingly
   *
   * Revision 1.4  2001/07/10 16:47:18  tronkko
   * revised comments
   *
   * Revision 1.3  2001/01/11 13:16:43  tr
   * using ``uce-machine.h'' for finding out defines such as `FREEBSD'
   *
   * Revision 1.2  2000/10/08 16:00:41  tr
   * copy of FreeBSD man page
   *
   * Revision 1.1  2000/07/10 05:53:16  tr
   * Initial revision
   *
   * Revision 1.2  1998/07/19 18:29:14  tr
   * Added error reporting capabilities and some asserts.
   *
   * Revision 1.1  1998/07/04 16:27:51  tr
   * Initial revision
   *
   *
   * MSVC 1.0 scans automatic dependencies incorrectly when your project
   * contains this very header.  The problem is that MSVC cannot handle
   * include directives inside #if..#endif block those are never entered.
   * Since this header ought to compile in many different operating systems,
   * there had to be several conditional blocks that are compiled only in
   * operating systems for what they were designed for.  MSVC 1.0 cannot
   * handle inclusion of sys/dir.h in a part that is compiled only in Apollo
   * operating system.  To fix the problem you need to insert DIR.H into
   * SYSINCL.DAT located in MSVC\BIN directory and restart visual C++.
   * Consult manuals for more informaton about the problem.
   *
   * Since many UNIX systems have dirent.h we assume to have one also.
   * However, if your UNIX system does not have dirent.h you can download one
   * for example at: http://ftp.uni-mannheim.de/ftp/GNU/dirent/dirent.tar.gz.
   * You can also see if you have one of dirent.h, direct.h, dir.h, ndir.h,
   * sys/dir.h and sys/ndir.h somewhere.  Try defining HAVE_DIRENT_H,
   * HAVE_DIRECT_H, HAVE_DIR_H, HAVE_NDIR_H, HAVE_SYS_DIR_H and
   * HAVE_SYS_NDIR_H according to the files found.
   */
  #ifndef DIRENT_H
  #define DIRENT_H
  #define DIRENT_H_INCLUDED
  
  /* find out platform */
  #if defined(MSDOS)                             /* MS-DOS */
  #elif defined(__MSDOS__)                       /* Turbo C/Borland */
  # define MSDOS
  #elif defined(__DOS__)                         /* Watcom */
  # define MSDOS
  #endif
  
  #if defined(WIN32)                             /* MS-Windows */
  #elif defined(__NT__)                          /* Watcom */
  # define WIN32
  #elif defined(_WIN32)                          /* Microsoft */
  # define WIN32
  #elif defined(__WIN32__)                       /* Borland */
  # define WIN32
  #endif
  
  /*
   * See what kind of dirent interface we have unless autoconf has already
   * determinated that.
   */
  #if !defined(HAVE_DIRENT_H) && !defined(HAVE_DIRECT_H) && !defined(HAVE_SYS_DIR_H) && !defined(HAVE_NDIR_H) && !defined(HAVE_SYS_NDIR_H) && !defined(HAVE_DIR_H)
  # if defined(_MSC_VER)                         /* Microsoft C/C++ */
  /* no dirent.h */
  # elif defined(__MINGW32__)                    /* MinGW */
  /* no dirent.h */
  # elif defined(__BORLANDC__)                   /* Borland C/C++ */
  #   define HAVE_DIRENT_H
  #   define VOID_CLOSEDIR
  # elif defined(__TURBOC__)                     /* Borland Turbo C */
  /* no dirent.h */
  # elif defined(__WATCOMC__)                    /* Watcom C/C++ */
  #   define HAVE_DIRECT_H
  # elif defined(__apollo)                       /* Apollo */
  #   define HAVE_SYS_DIR_H
  # elif defined(__hpux)                         /* HP-UX */
  #   define HAVE_DIRENT_H
  # elif (defined(__alpha) || defined(__alpha__)) && !defined(__linux__)  /* Alpha OSF1 */
  #   error "not implemented"
  # elif defined(__sgi)                          /* Silicon Graphics */
  #   define HAVE_DIRENT_H
  # elif defined(sun) || defined(__sun)           /* Sun Solaris */
  #   define HAVE_DIRENT_H
  # elif defined(__FreeBSD__)                    /* FreeBSD */
  #   define HAVE_DIRENT_H
  # elif defined(__linux__)                      /* Linux */
  #   define HAVE_DIRENT_H
  # elif defined(__GNUC__)                       /* GNU C/C++ */
  #   define HAVE_DIRENT_H
  # else
  #   error "not implemented"
  # endif
  #endif
  
  /* include proper interface headers */
  #if defined(HAVE_DIRENT_H)
  # include <dirent.h>
  # ifdef FREEBSD
  #   define NAMLEN(dp) ((int)((dp)->d_namlen))
  # else
  #   define NAMLEN(dp) ((int)(strlen((dp)->d_name)))
  # endif
  
  #elif defined(HAVE_NDIR_H)
  # include <ndir.h>
  # define NAMLEN(dp) ((int)((dp)->d_namlen))
  
  #elif defined(HAVE_SYS_NDIR_H)
  # include <sys/ndir.h>
  # define NAMLEN(dp) ((int)((dp)->d_namlen))
  
  #elif defined(HAVE_DIRECT_H)
  # include <direct.h>
  # define NAMLEN(dp) ((int)((dp)->d_namlen))
  
  #elif defined(HAVE_DIR_H)
  # include <dir.h>
  # define NAMLEN(dp) ((int)((dp)->d_namlen))
  
  #elif defined(HAVE_SYS_DIR_H)
  # include <sys/types.h>
  # include <sys/dir.h>
  # ifndef dirent
  #   define dirent direct
  # endif
  # define NAMLEN(dp) ((int)((dp)->d_namlen))
  
  #elif defined(MSDOS) || defined(WIN32)
  
  /* figure out type of underlaying directory interface to be used */
  # if defined(WIN32)
  #   define DIRENT_WIN32_INTERFACE
  # elif defined(MSDOS)
  #   define DIRENT_MSDOS_INTERFACE
  # else
  #   error "missing native dirent interface"
  # endif
  
  /*** WIN32 specifics ***/
  # if defined(DIRENT_WIN32_INTERFACE)
  #   include <windows.h>
  #   if !defined(DIRENT_MAXNAMLEN)
  #     define DIRENT_MAXNAMLEN (MAX_PATH)
  #   endif
  
  
  /*** MS-DOS specifics ***/
  # elif defined(DIRENT_MSDOS_INTERFACE)
  #   include <dos.h>
  
  /* Borland defines file length macros in dir.h */
  #   if defined(__BORLANDC__)
  #     include <dir.h>
  #     if !defined(DIRENT_MAXNAMLEN)
  #       define DIRENT_MAXNAMLEN ((MAXFILE)+(MAXEXT))
  #     endif
  #     if !defined(_find_t)
  #       define _find_t find_t
  #     endif
  
  /* Turbo C defines ffblk structure in dir.h */
  #   elif defined(__TURBOC__)
  #     include <dir.h>
  #     if !defined(DIRENT_MAXNAMLEN)
  #       define DIRENT_MAXNAMLEN ((MAXFILE)+(MAXEXT))
  #     endif
  #     define DIRENT_USE_FFBLK
  
  /* MSVC */
  #   elif defined(_MSC_VER)
  #     if !defined(DIRENT_MAXNAMLEN)
  #       define DIRENT_MAXNAMLEN (12)
  #     endif
  
  /* Watcom */
  #   elif defined(__WATCOMC__)
  #     if !defined(DIRENT_MAXNAMLEN)
  #       if defined(__OS2__) || defined(__NT__)
  #         define DIRENT_MAXNAMLEN (255)
  #       else
  #         define DIRENT_MAXNAMLEN (12)
  #       endif
  #     endif
  
  #   endif
  # endif
  
  /*** generic MS-DOS and MS-Windows stuff ***/
  # if !defined(NAME_MAX) && defined(DIRENT_MAXNAMLEN)
  #   define NAME_MAX DIRENT_MAXNAMLEN
  # endif
  # if NAME_MAX < DIRENT_MAXNAMLEN
  #   error "assertion failed: NAME_MAX >= DIRENT_MAXNAMLEN"
  # endif
  
  
  /*
   * Substitute for real dirent structure.  Note that `d_name' field is a
   * true character array although we have it copied in the implementation
   * dependent data.  We could save some memory if we had declared `d_name'
   * as a pointer referring the name within implementation dependent data.
   * We have not done that since some code may rely on sizeof(d_name) to be
   * something other than four.  Besides, directory entries are typically so
   * small that it takes virtually no time to copy them from place to place.
   */
  typedef struct dirent {
      char d_name[NAME_MAX + 1];
  
      /*** Operating system specific part ***/
  # if defined(DIRENT_WIN32_INTERFACE)       /*WIN32*/
      WIN32_FIND_DATA data;
  # elif defined(DIRENT_MSDOS_INTERFACE)     /*MSDOS*/
  #   if defined(DIRENT_USE_FFBLK)
      struct ffblk data;
  #   else
      struct _find_t data;
  #   endif
  # endif
  } dirent;
  
  /* DIR substitute structure containing directory name.  The name is
   * essential for the operation of ``rewinndir'' function. */
  typedef struct DIR {
      char          *dirname;                    /* directory being scanned */
      dirent        current;                     /* current entry */
      int           dirent_filled;               /* is current un-processed? */
  
      /*** Operating system specific part ***/
  #  if defined(DIRENT_WIN32_INTERFACE)
      HANDLE        search_handle;
  #  elif defined(DIRENT_MSDOS_INTERFACE)
  #  endif
  } DIR;
  
  # ifdef __cplusplus
  extern "C" {
  # endif
  
  /* supply prototypes for dirent functions */
  static DIR *opendir(const char *dirname);
  static struct dirent *readdir(DIR *dirp);
  static int closedir(DIR *dirp);
  static void rewinddir(DIR *dirp);
  
  /*
   * Implement dirent interface as static functions so that the user does not
   * need to change his project in any way to use dirent function.  With this
   * it is sufficient to include this very header from source modules using
   * dirent functions and the functions will be pulled in automatically.
   */
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <assert.h>
  #include <errno.h>
  
  /* use ffblk instead of _find_t if requested */
  #if defined(DIRENT_USE_FFBLK)
  # define _A_ARCH   (FA_ARCH)
  # define _A_HIDDEN (FA_HIDDEN)
  # define _A_NORMAL (0)
  # define _A_RDONLY (FA_RDONLY)
  # define _A_SUBDIR (FA_DIREC)
  # define _A_SYSTEM (FA_SYSTEM)
  # define _A_VOLID  (FA_LABEL)
  # define _dos_findnext(dest) findnext(dest)
  # define _dos_findfirst(name,flags,dest) findfirst(name,dest,flags)
  #endif
  
  static int _initdir(DIR *p);
  static const char *_getdirname(const struct dirent *dp);
  static void _setdirname(struct DIR *dirp);
  
  /*
   * <function name="opendir">
   * <intro>open directory stream for reading
   * <syntax>DIR *opendir (const char *dirname);
   *
   * <desc>Open named directory stream for read and return pointer to the
   * internal working area that is used for retrieving individual directory
   * entries.  The internal working area has no fields of your interest.
   *
   * <ret>Returns a pointer to the internal working area or NULL in case the
   * directory stream could not be opened.  Global `errno' variable will set
   * in case of error as follows:
   *
   * <table>
   * [EACESS  |Permission denied.
   * [EMFILE  |Too many open files used by the process.
   * [ENFILE  |Too many open files in system.
   * [ENOENT  |Directory does not exist.
   * [ENOMEM  |Insufficient memory.
   * [ENOTDIR |dirname does not refer to directory.  This value is not
   *           reliable on MS-DOS and MS-Windows platforms.  Many
   *           implementations return ENOENT even when the name refers to a
   *           file.]
   * </table>
   * </function>
   */
  static DIR *opendir(const char *dirname)
  {
      DIR *dirp;
      assert(dirname != NULL);
  
      dirp = (DIR*)malloc(sizeof(struct DIR));
      if (dirp != NULL) {
          char *p;
  
          /* allocate room for directory name */
          dirp->dirname = (char*) malloc(strlen(dirname) + 1 + strlen("\\*.*"));
          if (dirp->dirname == NULL) {
              /* failed to duplicate directory name.  errno set by malloc() */
              free(dirp);
              return NULL;
          }
          /* Copy directory name while appending directory separator and "*.*".
           * Directory separator is not appended if the name already ends with
           * drive or directory separator.  Directory separator is assumed to be
           * '/' or '\' and drive separator is assumed to be ':'. */
          strcpy(dirp->dirname, dirname);
          p = strchr(dirp->dirname, '\0');
          if (dirp->dirname < p  &&
                  *(p - 1) != '\\'  &&  *(p - 1) != '/'  &&  *(p - 1) != ':') {
              strcpy(p++, "\\");
          }
  # ifdef DIRENT_WIN32_INTERFACE
          strcpy(p, "*");  /*scan files with and without extension in win32*/
  # else
          strcpy(p, "*.*");  /*scan files with and without extension in DOS*/
  # endif
  
          /* open stream */
          if (_initdir(dirp) == 0) {
              /* initialization failed */
              free(dirp->dirname);
              free(dirp);
              return NULL;
          }
      }
      return dirp;
  }
  
  
  /*
   * <function name="readdir">
   * <intro>read a directory entry
   * <syntax>struct dirent *readdir (DIR *dirp);
   *
   * <desc>Read individual directory entry and return pointer to a structure
   * containing the name of the entry.  Individual directory entries returned
   * include normal files, sub-directories, pseudo-directories "." and ".."
   * and also volume labels, hidden files and system files in MS-DOS and
   * MS-Windows.   You might want to use stat(2) function to determinate which
   * one are you dealing with.  Many dirent implementations already contain
   * equivalent information in dirent structure but you cannot depend on
   * this.
   *
   * The dirent structure contains several system dependent fields that
   * generally have no interest to you.  The only interesting one is char
   * d_name[] that is also portable across different systems.  The d_name
   * field contains the name of the directory entry without leading path.
   * While d_name is portable across different systems the actual storage
   * capacity of d_name varies from system to system and there is no portable
   * way to find out it at compile time as different systems define the
   * capacity of d_name with different macros and some systems do not define
   * capacity at all (besides actual declaration of the field). If you really
   * need to find out storage capacity of d_name then you might want to try
   * NAME_MAX macro. The NAME_MAX is defined in POSIX standard although
   * there are many MS-DOS and MS-Windows implementations those do not define
   * it.  There are also systems that declare d_name as "char d_name[1]" and
   * then allocate suitable amount of memory at run-time.  Thanks to Alain
   * Decamps (Alain.Decamps@advalvas.be) for pointing it out to me.
   *
   * This all leads to the fact that it is difficult to allocate space
   * for the directory names when the very same program is being compiled on
   * number of operating systems.  Therefore I suggest that you always
   * allocate space for directory names dynamically.
   *
   * <ret>
   * Returns a pointer to a structure containing name of the directory entry
   * in `d_name' field or NULL if there was an error.  In case of an error the
   * global `errno' variable will set as follows:
   *
   * <table>
   * [EBADF  |dir parameter refers to an invalid directory stream.  This value
   *          is not set reliably on all implementations.]
   * </table>
   * </function>
   */
  static struct dirent *
  readdir(DIR *dirp)
  {
      assert(dirp != NULL);
      if (dirp == NULL) {
          errno = EBADF;
          return NULL;
      }
  
  #if defined(DIRENT_WIN32_INTERFACE)
      if (dirp->search_handle == INVALID_HANDLE_VALUE) {
          /* directory stream was opened/rewound incorrectly or it ended normally */
          errno = EBADF;
          return NULL;
      }
  #endif
  
      if (dirp->dirent_filled != 0) {
          /*
           * Directory entry has already been retrieved and there is no need to
           * retrieve a new one.  Directory entry will be retrieved in advance
           * when the user calls readdir function for the first time.  This is so
           * because real dirent has separate functions for opening and reading
           * the stream whereas Win32 and DOS dirents open the stream
           * automatically when we retrieve the first file.  Therefore, we have to
           * save the first file when opening the stream and later we have to
           * return the saved entry when the user tries to read the first entry.
           */
          dirp->dirent_filled = 0;
      } else {
          /* fill in entry and return that */
  #if defined(DIRENT_WIN32_INTERFACE)
          if (FindNextFile(dirp->search_handle, &dirp->current.data) == FALSE) {
              /* Last file has been processed or an error occurred */
              FindClose(dirp->search_handle);
              dirp->search_handle = INVALID_HANDLE_VALUE;
              errno = ENOENT;
              return NULL;
          }
  
  # elif defined(DIRENT_MSDOS_INTERFACE)
          if (_dos_findnext(&dirp->current.data) != 0) {
              /* _dos_findnext and findnext will set errno to ENOENT when no
               * more entries could be retrieved. */
              return NULL;
          }
  # endif
  
          _setdirname(dirp);
          assert(dirp->dirent_filled == 0);
      }
      return &dirp->current;
  }
  
  
  /*
   * <function name="closedir">
   * <intro>close directory stream.
   * <syntax>int closedir (DIR *dirp);
   *
   * <desc>Close directory stream opened by the `opendir' function.  Close of
   * directory stream invalidates the DIR structure as well as previously read
   * dirent entry.
   *
   * <ret>The function typically returns 0 on success and -1 on failure but
   * the function may be declared to return void on same systems.  At least
   * Borland C/C++ and some UNIX implementations use void as a return type.
   * The dirent wrapper tries to define VOID_CLOSEDIR whenever closedir is
   * known to return nothing.  The very same definition is made by the GNU
   * autoconf if you happen to use it.
   *
   * The global `errno' variable will set to EBADF in case of error.
   * </function>
   */
  static int
  closedir(DIR *dirp)
  {
      int retcode = 0;
  
      /* make sure that dirp points to legal structure */
      assert(dirp != NULL);
      if (dirp == NULL) {
          errno = EBADF;
          return -1;
      }
  
      /* free directory name and search handles */
      if (dirp->dirname != NULL) {
          free(dirp->dirname);
      }
  
  #if defined(DIRENT_WIN32_INTERFACE)
      if (dirp->search_handle != INVALID_HANDLE_VALUE) {
          if (FindClose(dirp->search_handle) == FALSE) {
              /* Unknown error */
              retcode = -1;
              errno = EBADF;
          }
      }
  #endif
  
      /* clear dirp structure to make sure that it cannot be used anymore*/
      memset(dirp, 0, sizeof(*dirp));
  # if defined(DIRENT_WIN32_INTERFACE)
      dirp->search_handle = INVALID_HANDLE_VALUE;
  # endif
  
      free(dirp);
      return retcode;
  }
  
  
  /*
   * <function name="rewinddir">
   * <intro>rewind directory stream to the beginning
   * <syntax>void rewinddir (DIR *dirp);
   *
   * <desc>Rewind directory stream to the beginning so that the next call of
   * readdir() returns the very first directory entry again.  However, note
   * that next call of readdir() may not return the same directory entry as it
   * did in first time.  The directory stream may have been affected by newly
   * created files.
   *
   * Almost every dirent implementation ensure that rewinddir will update
   * the directory stream to reflect any changes made to the directory entries
   * since the previous ``opendir'' or ``rewinddir'' call.  Keep an eye on
   * this if your program depends on the feature.  I know at least one dirent
   * implementation where you are required to close and re-open the stream to
   * see the changes.
   *
   * <ret>Returns nothing.  If something went wrong while rewinding, you will
   * notice it later when you try to retrieve the first directory entry.
   */
  static void
  rewinddir(DIR *dirp)
  {
      /* make sure that dirp is legal */
      assert(dirp != NULL);
      if (dirp == NULL) {
          errno = EBADF;
          return;
      }
      assert(dirp->dirname != NULL);
  
      /* close previous stream */
  #if defined(DIRENT_WIN32_INTERFACE)
      if (dirp->search_handle != INVALID_HANDLE_VALUE) {
          if (FindClose(dirp->search_handle) == FALSE) {
              /* Unknown error */
              errno = EBADF;
          }
      }
  #endif
  
      /* re-open previous stream */
      if (_initdir(dirp) == 0) {
          /* initialization failed but we cannot deal with error.  User will notice
           * error later when she tries to retrieve first directory enty. */
          /*EMPTY*/;
      }
  }
  
  
  /*
   * Open native directory stream object and retrieve first file.
   * Be sure to close previous stream before opening new one.
   */
  static int
  _initdir(DIR *dirp)
  {
      assert(dirp != NULL);
      assert(dirp->dirname != NULL);
      dirp->dirent_filled = 0;
  
  # if defined(DIRENT_WIN32_INTERFACE)
      /* Open stream and retrieve first file */
      dirp->search_handle = FindFirstFile(dirp->dirname, &dirp->current.data);
      if (dirp->search_handle == INVALID_HANDLE_VALUE) {
          /* something went wrong but we don't know what.  GetLastError() could
           * give us more information about the error, but then we should map
           * the error code into errno. */
          errno = ENOENT;
          return 0;
      }
  
  # elif defined(DIRENT_MSDOS_INTERFACE)
      if (_dos_findfirst(dirp->dirname,
                         _A_SUBDIR | _A_RDONLY | _A_ARCH | _A_SYSTEM | _A_HIDDEN,
                         &dirp->current.data) != 0) {
          /* _dos_findfirst and findfirst will set errno to ENOENT when no
           * more entries could be retrieved. */
          return 0;
      }
  # endif
  
      /* initialize DIR and it's first entry */
      _setdirname(dirp);
      dirp->dirent_filled = 1;
      return 1;
  }
  
  
  /*
   * Return implementation dependent name of the current directory entry.
   */
  static const char *
  _getdirname(const struct dirent *dp)
  {
  #if defined(DIRENT_WIN32_INTERFACE)
      return dp->data.cFileName;
  
  #elif defined(DIRENT_USE_FFBLK)
      return dp->data.ff_name;
  
  #else
      return dp->data.name;
  #endif
  }
  
  
  /*
   * Copy name of implementation dependent directory entry to the d_name field.
   */
  static void
  _setdirname(struct DIR *dirp)
  {
      /* make sure that d_name is long enough */
      assert(strlen(_getdirname(&dirp->current)) <= NAME_MAX);
  
      strncpy(dirp->current.d_name,
              _getdirname(&dirp->current),
              NAME_MAX);
      dirp->current.d_name[NAME_MAX] = '\0'; /*char d_name[NAME_MAX+1]*/
  }
  
  # ifdef __cplusplus
  }
  # endif
  # define NAMLEN(dp) ((int)(strlen((dp)->d_name)))
  
  #else
  # error "missing dirent interface"
  #endif
  
  
  #endif /*DIRENT_H*/
  