1 /* Return basename of given pathname according to the weird XPG specification.
2 Copyright (C) 1997-2022 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library 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 GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19 #include <string.h>
20 #include <libgen.h>
21
22
23 char *
__xpg_basename(char * filename)24 __xpg_basename (char *filename)
25 {
26 char *p;
27
28 if (filename == NULL || filename[0] == '\0')
29 /* We return a pointer to a static string containing ".". */
30 p = (char *) ".";
31 else
32 {
33 p = strrchr (filename, '/');
34
35 if (p == NULL)
36 /* There is no slash in the filename. Return the whole string. */
37 p = filename;
38 else
39 {
40 if (p[1] == '\0')
41 {
42 /* We must remove trailing '/'. */
43 while (p > filename && p[-1] == '/')
44 --p;
45
46 /* Now we can be in two situations:
47 a) the string only contains '/' characters, so we return
48 '/'
49 b) p points past the last component, but we have to remove
50 the trailing slash. */
51 if (p > filename)
52 {
53 *p-- = '\0';
54 while (p > filename && p[-1] != '/')
55 --p;
56 }
57 else
58 /* The last slash we already found is the right position
59 to return. */
60 while (p[1] != '\0')
61 ++p;
62 }
63 else
64 /* Go to the first character of the name. */
65 ++p;
66 }
67 }
68
69 return p;
70 }
71