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Diffstat (limited to 'gl/basename.c')
-rw-r--r-- | gl/basename.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/gl/basename.c b/gl/basename.c new file mode 100644 index 0000000..fbe17ff --- /dev/null +++ b/gl/basename.c | |||
@@ -0,0 +1,129 @@ | |||
1 | /* basename.c -- return the last element in a file name | ||
2 | |||
3 | Copyright (C) 1990, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006 Free | ||
4 | Software 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 2, or (at your option) | ||
9 | 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, write to the Free Software Foundation, | ||
18 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | ||
19 | |||
20 | #include <config.h> | ||
21 | |||
22 | #include "dirname.h" | ||
23 | |||
24 | #include <string.h> | ||
25 | #include "xalloc.h" | ||
26 | #include "xstrndup.h" | ||
27 | |||
28 | /* Return the address of the last file name component of NAME. If | ||
29 | NAME has no relative file name components because it is a file | ||
30 | system root, return the empty string. */ | ||
31 | |||
32 | char * | ||
33 | last_component (char const *name) | ||
34 | { | ||
35 | char const *base = name + FILE_SYSTEM_PREFIX_LEN (name); | ||
36 | char const *p; | ||
37 | bool saw_slash = false; | ||
38 | |||
39 | while (ISSLASH (*base)) | ||
40 | base++; | ||
41 | |||
42 | for (p = base; *p; p++) | ||
43 | { | ||
44 | if (ISSLASH (*p)) | ||
45 | saw_slash = true; | ||
46 | else if (saw_slash) | ||
47 | { | ||
48 | base = p; | ||
49 | saw_slash = false; | ||
50 | } | ||
51 | } | ||
52 | |||
53 | return (char *) base; | ||
54 | } | ||
55 | |||
56 | |||
57 | /* In general, we can't use the builtin `basename' function if available, | ||
58 | since it has different meanings in different environments. | ||
59 | In some environments the builtin `basename' modifies its argument. | ||
60 | |||
61 | Return the last file name component of NAME, allocated with | ||
62 | xmalloc. On systems with drive letters, a leading "./" | ||
63 | distinguishes relative names that would otherwise look like a drive | ||
64 | letter. Unlike POSIX basename(), NAME cannot be NULL, | ||
65 | base_name("") returns "", and the first trailing slash is not | ||
66 | stripped. | ||
67 | |||
68 | If lstat (NAME) would succeed, then { chdir (dir_name (NAME)); | ||
69 | lstat (base_name (NAME)); } will access the same file. Likewise, | ||
70 | if the sequence { chdir (dir_name (NAME)); | ||
71 | rename (base_name (NAME), "foo"); } succeeds, you have renamed NAME | ||
72 | to "foo" in the same directory NAME was in. */ | ||
73 | |||
74 | char * | ||
75 | base_name (char const *name) | ||
76 | { | ||
77 | char const *base = last_component (name); | ||
78 | size_t length; | ||
79 | |||
80 | /* If there is no last component, then name is a file system root or the | ||
81 | empty string. */ | ||
82 | if (! *base) | ||
83 | return xstrndup (name, base_len (name)); | ||
84 | |||
85 | /* Collapse a sequence of trailing slashes into one. */ | ||
86 | length = base_len (base); | ||
87 | if (ISSLASH (base[length])) | ||
88 | length++; | ||
89 | |||
90 | /* On systems with drive letters, `a/b:c' must return `./b:c' rather | ||
91 | than `b:c' to avoid confusion with a drive letter. On systems | ||
92 | with pure POSIX semantics, this is not an issue. */ | ||
93 | if (FILE_SYSTEM_PREFIX_LEN (base)) | ||
94 | { | ||
95 | char *p = xmalloc (length + 3); | ||
96 | p[0] = '.'; | ||
97 | p[1] = '/'; | ||
98 | memcpy (p + 2, base, length); | ||
99 | p[length + 2] = '\0'; | ||
100 | return p; | ||
101 | } | ||
102 | |||
103 | /* Finally, copy the basename. */ | ||
104 | return xstrndup (base, length); | ||
105 | } | ||
106 | |||
107 | /* Return the length of the basename NAME. Typically NAME is the | ||
108 | value returned by base_name or last_component. Act like strlen | ||
109 | (NAME), except omit all trailing slashes. */ | ||
110 | |||
111 | size_t | ||
112 | base_len (char const *name) | ||
113 | { | ||
114 | size_t len; | ||
115 | size_t prefix_len = FILE_SYSTEM_PREFIX_LEN (name); | ||
116 | |||
117 | for (len = strlen (name); 1 < len && ISSLASH (name[len - 1]); len--) | ||
118 | continue; | ||
119 | |||
120 | if (DOUBLE_SLASH_IS_DISTINCT_ROOT && len == 1 | ||
121 | && ISSLASH (name[0]) && ISSLASH (name[1]) && ! name[2]) | ||
122 | return 2; | ||
123 | |||
124 | if (FILE_SYSTEM_DRIVE_PREFIX_CAN_BE_RELATIVE && prefix_len | ||
125 | && len == prefix_len && ISSLASH (name[prefix_len])) | ||
126 | return prefix_len + 1; | ||
127 | |||
128 | return len; | ||
129 | } | ||