1/* basename.c -- return the last element in a file name
2
3 Copyright (C) 1990, 1998-2001, 2003-2006, 2009-2019 Free Software
4 Foundation, Inc.
5
6 This program is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <https://www.gnu.org/licenses/>. */
18
19#include <config.h>
20
21#include "dirname.h"
22
23#include <string.h>
24
25/* Return the address of the last file name component of NAME. If
26 NAME has no relative file name components because it is a file
27 system root, return the empty string. */
28
29char *
30last_component (char const *name)
31{
32 char const *base = name + FILE_SYSTEM_PREFIX_LEN (name);
33 char const *p;
34 bool saw_slash = false;
35
36 while (ISSLASH (*base))
37 base++;
38
39 for (p = base; *p; p++)
40 {
41 if (ISSLASH (*p))
42 saw_slash = true;
43 else if (saw_slash)
44 {
45 base = p;
46 saw_slash = false;
47 }
48 }
49
50 return (char *) base;
51}
52
53/* Return the length of the basename NAME. Typically NAME is the
54 value returned by base_name or last_component. Act like strlen
55 (NAME), except omit all trailing slashes. */
56
57size_t
58base_len (char const *name)
59{
60 size_t len;
61 size_t prefix_len = FILE_SYSTEM_PREFIX_LEN (name);
62
63 for (len = strlen (name); 1 < len && ISSLASH (name[len - 1]); len--)
64 continue;
65
66 if (DOUBLE_SLASH_IS_DISTINCT_ROOT && len == 1
67 && ISSLASH (name[0]) && ISSLASH (name[1]) && ! name[2])
68 return 2;
69
70 if (FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE && prefix_len
71 && len == prefix_len && ISSLASH (name[prefix_len]))
72 return prefix_len + 1;
73
74 return len;
75}
76