af_alg: Improve comments.
[gnulib.git] / lib / dosname.h
blobfef3b6daa1ffe446259dcb442c349735dbeaca57
1 /* File names on MS-DOS/Windows systems.
3 Copyright (C) 2000-2001, 2004-2006, 2009-2018 Free Software Foundation, Inc.
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <https://www.gnu.org/licenses/>.
18 From Paul Eggert and Jim Meyering. */
20 #ifndef _DOSNAME_H
21 #define _DOSNAME_H
23 #if (defined _WIN32 || defined __CYGWIN__ \
24 || defined __EMX__ || defined __MSDOS__ || defined __DJGPP__)
25 /* This internal macro assumes ASCII, but all hosts that support drive
26 letters use ASCII. */
27 # define _IS_DRIVE_LETTER(C) (((unsigned int) (C) | ('a' - 'A')) - 'a' \
28 <= 'z' - 'a')
29 # define FILE_SYSTEM_PREFIX_LEN(Filename) \
30 (_IS_DRIVE_LETTER ((Filename)[0]) && (Filename)[1] == ':' ? 2 : 0)
31 # ifndef __CYGWIN__
32 # define FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 1
33 # endif
34 # define ISSLASH(C) ((C) == '/' || (C) == '\\')
35 #else
36 # define FILE_SYSTEM_PREFIX_LEN(Filename) 0
37 # define ISSLASH(C) ((C) == '/')
38 #endif
40 #ifndef FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE
41 # define FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 0
42 #endif
44 #if FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE
45 # define IS_ABSOLUTE_FILE_NAME(F) ISSLASH ((F)[FILE_SYSTEM_PREFIX_LEN (F)])
46 # else
47 # define IS_ABSOLUTE_FILE_NAME(F) \
48 (ISSLASH ((F)[0]) || FILE_SYSTEM_PREFIX_LEN (F) != 0)
49 #endif
50 #define IS_RELATIVE_FILE_NAME(F) (! IS_ABSOLUTE_FILE_NAME (F))
52 #endif /* DOSNAME_H_ */