1 /* Basic filename support macros. 2 Copyright (C) 2001-2004, 2007-2020 Free Software Foundation, Inc. 3 4 This program is free software: you can redistribute it and/or modify 5 it under the terms of the GNU General Public License as published by 6 the Free Software Foundation; either version 3 of the License, or 7 (at your option) any later version. 8 9 This program is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 GNU General Public License for more details. 13 14 You should have received a copy of the GNU General Public License 15 along with this program. If not, see <https://www.gnu.org/licenses/>. */ 16 17 /* From Paul Eggert and Jim Meyering. */ 18 19 #ifndef _FILENAME_H 20 #define _FILENAME_H 21 22 #include <string.h> 23 24 #ifdef __cplusplus 25 extern "C" { 26 #endif 27 28 29 /* Filename support. 30 ISSLASH(C) tests whether C is a directory separator 31 character. 32 HAS_DEVICE(Filename) tests whether Filename contains a device 33 specification. 34 FILE_SYSTEM_PREFIX_LEN(Filename) length of the device specification 35 at the beginning of Filename, 36 index of the part consisting of 37 alternating components and slashes. 38 FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 39 1 when a non-empty device specification 40 can be followed by an empty or relative 41 part, 42 0 when a non-empty device specification 43 must be followed by a slash, 44 0 when device specification don't exist. 45 IS_ABSOLUTE_FILE_NAME(Filename) 46 tests whether Filename is independent of 47 any notion of "current directory". 48 IS_RELATIVE_FILE_NAME(Filename) 49 tests whether Filename may be concatenated 50 to a directory filename. 51 Note: On native Windows, OS/2, DOS, "c:" is neither an absolute nor a 52 relative file name! 53 IS_FILE_NAME_WITH_DIR(Filename) tests whether Filename contains a device 54 or directory specification. 55 */ 56 #if defined _WIN32 || defined __CYGWIN__ \ 57 || defined __EMX__ || defined __MSDOS__ || defined __DJGPP__ 58 /* Native Windows, Cygwin, OS/2, DOS */ 59 # define ISSLASH(C) ((C) == '/' || (C) == '\\') 60 /* Internal macro: Tests whether a character is a drive letter. */ 61 # define _IS_DRIVE_LETTER(C) \ 62 (((C) >= 'A' && (C) <= 'Z') || ((C) >= 'a' && (C) <= 'z')) 63 /* Help the compiler optimizing it. This assumes ASCII. */ 64 # undef _IS_DRIVE_LETTER 65 # define _IS_DRIVE_LETTER(C) \ 66 (((unsigned int) (C) | ('a' - 'A')) - 'a' <= 'z' - 'a') 67 # define HAS_DEVICE(Filename) \ 68 (_IS_DRIVE_LETTER ((Filename)[0]) && (Filename)[1] == ':') 69 # define FILE_SYSTEM_PREFIX_LEN(Filename) (HAS_DEVICE (Filename) ? 2 : 0) 70 # ifdef __CYGWIN__ 71 # define FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 0 72 # else 73 /* On native Windows, OS/2, DOS, the system has the notion of a 74 "current directory" on each drive. */ 75 # define FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 1 76 # endif 77 # if FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 78 # define IS_ABSOLUTE_FILE_NAME(Filename) \ 79 ISSLASH ((Filename)[FILE_SYSTEM_PREFIX_LEN (Filename)]) 80 # else 81 # define IS_ABSOLUTE_FILE_NAME(Filename) \ 82 (ISSLASH ((Filename)[0]) || HAS_DEVICE (Filename)) 83 # endif 84 # define IS_RELATIVE_FILE_NAME(Filename) \ 85 (! (ISSLASH ((Filename)[0]) || HAS_DEVICE (Filename))) 86 # define IS_FILE_NAME_WITH_DIR(Filename) \ 87 (strchr ((Filename), '/') != NULL || strchr ((Filename), '\\') != NULL \ 88 || HAS_DEVICE (Filename)) 89 #else 90 /* Unix */ 91 # define ISSLASH(C) ((C) == '/') 92 # define HAS_DEVICE(Filename) ((void) (Filename), 0) 93 # define FILE_SYSTEM_PREFIX_LEN(Filename) ((void) (Filename), 0) 94 # define FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE 0 95 # define IS_ABSOLUTE_FILE_NAME(Filename) ISSLASH ((Filename)[0]) 96 # define IS_RELATIVE_FILE_NAME(Filename) (! ISSLASH ((Filename)[0])) 97 # define IS_FILE_NAME_WITH_DIR(Filename) (strchr ((Filename), '/') != NULL) 98 #endif 99 100 /* Deprecated macros. For backward compatibility with old users of the 101 'filename' module. */ 102 #define IS_ABSOLUTE_PATH IS_ABSOLUTE_FILE_NAME 103 #define IS_PATH_WITH_DIR IS_FILE_NAME_WITH_DIR 104 105 106 #ifdef __cplusplus 107 } 108 #endif 109 110 #endif /* _FILENAME_H */ 111