1 | /* Filename lookup using a search path |
2 | Copyright (C) 1995-2022 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 <hurd.h> |
21 | #include <hurd/lookup.h> |
22 | |
23 | /* If FILE_NAME contains a '/', or PATH is NULL, call FUN with FILE_NAME, and |
24 | return the result (if PREFIXED_NAME is non-NULL, setting *PREFIXED_NAME to |
25 | NULL). Otherwise, call FUN repeatedly with FILE_NAME prefixed with each |
26 | successive `:' separated element of PATH, returning whenever FUN returns |
27 | 0 (if PREFIXED_NAME is non-NULL, setting *PREFIXED_NAME to the resulting |
28 | prefixed path). If FUN never returns 0, return the first non-ENOENT |
29 | return value, or ENOENT if there is none. */ |
30 | error_t |
31 | file_name_path_scan (const char *file_name, const char *path, |
32 | error_t (*fun)(const char *name), |
33 | char **prefixed_name) |
34 | { |
35 | if (path == NULL || strchr (s: file_name, c: '/')) |
36 | { |
37 | if (prefixed_name) |
38 | *prefixed_name = 0; |
39 | return (*fun)(file_name); |
40 | } |
41 | else |
42 | { |
43 | error_t real_err = 0; |
44 | size_t file_name_len = strlen (s: file_name); |
45 | |
46 | for (;;) |
47 | { |
48 | error_t err; |
49 | const char *next = strchr (s: path, c: ':') ?: path + strlen (s: path); |
50 | size_t pfx_len = next - path; |
51 | char pfxed_name[pfx_len + 2 + file_name_len + 1]; |
52 | |
53 | if (pfx_len == 0) |
54 | pfxed_name[pfx_len++] = '.'; |
55 | else |
56 | memcpy (dest: pfxed_name, src: path, n: pfx_len); |
57 | if (pfxed_name[pfx_len - 1] != '/') |
58 | pfxed_name[pfx_len++] = '/'; |
59 | memcpy (dest: pfxed_name + pfx_len, src: file_name, n: file_name_len + 1); |
60 | |
61 | err = (*fun)(pfxed_name); |
62 | if (err == 0) |
63 | { |
64 | if (prefixed_name) |
65 | *prefixed_name = __strdup (string: pfxed_name); |
66 | return 0; |
67 | } |
68 | if (!real_err && err != ENOENT) |
69 | real_err = err; |
70 | |
71 | if (*next == '\0') |
72 | return real_err ?: ENOENT; |
73 | else |
74 | path = next + 1; |
75 | } |
76 | } |
77 | } |
78 | |
79 | /* Lookup FILE_NAME and return the node opened with FLAGS & MODE in result |
80 | (see hurd_file_name_lookup for details), but a simple filename (without |
81 | any directory prefixes) will be consecutively prefixed with the pathnames |
82 | in the `:' separated list PATH until one succeeds in a successful lookup. |
83 | If none succeed, then the first error that wasn't ENOENT is returned, or |
84 | ENOENT if no other errors were returned. If PREFIXED_NAME is non-NULL, |
85 | then if RESULT is looked up directly, *PREFIXED_NAME is set to NULL, and |
86 | if it is looked up using a prefix from PATH, *PREFIXED_NAME is set to |
87 | malloced storage containing the prefixed name. */ |
88 | error_t |
89 | __hurd_file_name_path_lookup (error_t (*use_init_port) |
90 | (int which, error_t (*operate) (mach_port_t)), |
91 | file_t (*get_dtable_port) (int fd), |
92 | error_t (*lookup) |
93 | (file_t dir, const char *name, int flags, mode_t mode, |
94 | retry_type *do_retry, string_t retry_name, |
95 | mach_port_t *result), |
96 | const char *file_name, const char *path, |
97 | int flags, mode_t mode, |
98 | file_t *result, char **prefixed_name) |
99 | { |
100 | error_t scan_lookup (const char *name) |
101 | { |
102 | return |
103 | __hurd_file_name_lookup (use_init_port, get_dtable_port, lookup, |
104 | name, flags, mode, result); |
105 | } |
106 | return file_name_path_scan (file_name, path, scan_lookup, prefixed_name); |
107 | } |
108 | strong_alias (__hurd_file_name_path_lookup, hurd_file_name_path_lookup) |
109 | |
110 | file_t |
111 | file_name_path_lookup (const char *file_name, const char *path, |
112 | int flags, mode_t mode, char **prefixed_name) |
113 | { |
114 | error_t err; |
115 | file_t result; |
116 | |
117 | err = __hurd_file_name_path_lookup (&_hurd_ports_use, &__getdport, 0, |
118 | file_name, path, flags, mode, |
119 | &result, prefixed_name); |
120 | |
121 | return err ? (__hurd_fail (err), MACH_PORT_NULL) : result; |
122 | } |
123 | |