/* Basic filename support macros.

   Copyright (C) 2001-2004, 2007-2020 Free Software Foundation, Inc.

   This program 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.

   This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* From Paul Eggert and Jim Meyering.  */

#ifndef _FILENAME_H

#define _FILENAME_H

#include <string.h>

#ifdef __cplusplus

extern "C" {

#endif

/* Filename support.

   ISSLASH(C)                  tests whether C is a directory separator

                               character.

   HAS_DEVICE(Filename)        tests whether Filename contains a device

                               specification.

   FILE_SYSTEM_PREFIX_LEN(Filename)  length of the device specification

                                     at the beginning of Filename,

                                     index of the part consisting of

                                     alternating components and slashes.

   FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE

                               1 when a non-empty device specification

                               can be followed by an empty or relative

                               part,

                               0 when a non-empty device specification

                               must be followed by a slash,

                               0 when device specification don't exist.

   IS_ABSOLUTE_FILE_NAME(Filename)

                               tests whether Filename is independent of

                               any notion of "current directory".

   IS_RELATIVE_FILE_NAME(Filename)

                               tests whether Filename may be concatenated

                               to a directory filename.

   Note: On native Windows, OS/2, DOS, "c:" is neither an absolute nor a

   relative file name!

   IS_FILE_NAME_WITH_DIR(Filename)  tests whether Filename contains a device

                                    or directory specification.

 */

#if defined _WIN32 || defined __CYGWIN__ \

    || defined __EMX__ || defined __MSDOS__ || defined __DJGPP__

  /* Native Windows, Cygwin, OS/2, DOS */

# define ISSLASH(C) ((C) == '/' || (C) == '\\')

  /* Internal macro: Tests whether a character is a drive letter.  */

# define _IS_DRIVE_LETTER(C) \

    (((C) >= 'A' && (C) <= 'Z') || ((C) >= 'a' && (C) <= 'z'))

  /* Help the compiler optimizing it.  This assumes ASCII.  */

# undef _IS_DRIVE_LETTER

# define _IS_DRIVE_LETTER(C) \

    (((unsigned int) (C) | ('a' - 'A')) - 'a' <= 'z' - 'a')

# define HAS_DEVICE(Filename) \

    (_IS_DRIVE_LETTER ((Filename)[0]) && (Filename)[1] == ':')

# define FILE_SYSTEM_PREFIX_LEN(Filename) (HAS_DEVICE (Filename) ? 2 : 0)

# ifdef __CYGWIN__

#  define FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 0

# else

   /* On native Windows, OS/2, DOS, the system has the notion of a

      "current directory" on each drive.  */

#  define FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 1

# endif

# if FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE

#  define IS_ABSOLUTE_FILE_NAME(Filename) \

     ISSLASH ((Filename)[FILE_SYSTEM_PREFIX_LEN (Filename)])

# else

#  define IS_ABSOLUTE_FILE_NAME(Filename) \

     (ISSLASH ((Filename)[0]) || HAS_DEVICE (Filename))

# endif

# define IS_RELATIVE_FILE_NAME(Filename) \

    (! (ISSLASH ((Filename)[0]) || HAS_DEVICE (Filename)))

# define IS_FILE_NAME_WITH_DIR(Filename) \

    (strchr ((Filename), '/') != NULL || strchr ((Filename), '\\') != NULL \

     || HAS_DEVICE (Filename))

#else

  /* Unix */

# define ISSLASH(C) ((C) == '/')

# define HAS_DEVICE(Filename) ((void) (Filename), 0)

# define FILE_SYSTEM_PREFIX_LEN(Filename) ((void) (Filename), 0)

# define FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 0

# define IS_ABSOLUTE_FILE_NAME(Filename) ISSLASH ((Filename)[0])

# define IS_RELATIVE_FILE_NAME(Filename) (! ISSLASH ((Filename)[0]))

# define IS_FILE_NAME_WITH_DIR(Filename) (strchr ((Filename), '/') != NULL)

#endif

/* Deprecated macros.  For backward compatibility with old users of the

   'filename' module.  */

#define IS_ABSOLUTE_PATH IS_ABSOLUTE_FILE_NAME

#define IS_PATH_WITH_DIR IS_FILE_NAME_WITH_DIR

#ifdef __cplusplus

}

#endif

#endif /* _FILENAME_H */