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Commit | Line | Data |
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b72432fd JA |
1 | /* ln - make links */ |
2 | ||
3 | /* See Makefile for compilation details. */ | |
4 | ||
3185942a JA |
5 | /* |
6 | Copyright (C) 1999-2009 Free Software Foundation, Inc. | |
7 | ||
8 | This file is part of GNU Bash. | |
9 | Bash is free software: you can redistribute it and/or modify | |
10 | it under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation, either version 3 of the License, or | |
12 | (at your option) any later version. | |
13 | ||
14 | Bash is distributed in the hope that it will be useful, | |
15 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | GNU General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with Bash. If not, see <http://www.gnu.org/licenses/>. | |
21 | */ | |
22 | ||
b72432fd JA |
23 | #include "config.h" |
24 | ||
25 | #include "bashtypes.h" | |
26 | ||
27 | #if defined (HAVE_UNISTD_H) | |
28 | # include <unistd.h> | |
29 | #endif | |
30 | ||
31 | #include "posixstat.h" | |
32 | ||
33 | #include <stdio.h> | |
34 | #include <errno.h> | |
35 | ||
36 | #include "builtins.h" | |
37 | #include "shell.h" | |
38 | #include "bashgetopt.h" | |
3185942a | 39 | #include "common.h" |
b72432fd JA |
40 | |
41 | #if !defined (errno) | |
42 | extern int errno; | |
43 | #endif | |
44 | ||
f73dda09 JA |
45 | typedef int unix_link_syscall_t __P((const char *, const char *)); |
46 | ||
b72432fd JA |
47 | #define LN_SYMLINK 0x01 |
48 | #define LN_UNLINK 0x02 | |
a0c0a00f | 49 | #define LN_NOFOLLOW 0x04 |
b72432fd | 50 | |
f73dda09 | 51 | static unix_link_syscall_t *linkfn; |
b72432fd JA |
52 | static int dolink (); |
53 | ||
a0c0a00f | 54 | int |
b72432fd JA |
55 | ln_builtin (list) |
56 | WORD_LIST *list; | |
57 | { | |
58 | int rval, opt, flags; | |
59 | WORD_LIST *l; | |
60 | char *sdir; | |
61 | struct stat sb; | |
62 | ||
63 | flags = 0; | |
64 | reset_internal_getopt (); | |
65 | while ((opt = internal_getopt (list, "fs")) != -1) | |
66 | { | |
67 | switch (opt) | |
68 | { | |
69 | case 'f': | |
70 | flags |= LN_UNLINK; | |
71 | break; | |
72 | case 's': | |
73 | flags |= LN_SYMLINK; | |
74 | break; | |
a0c0a00f CR |
75 | case 'h': |
76 | case 'n': | |
77 | flags |= LN_NOFOLLOW; | |
78 | break; | |
d233b485 | 79 | CASE_HELPOPT; |
b72432fd JA |
80 | default: |
81 | builtin_usage (); | |
82 | return (EX_USAGE); | |
83 | } | |
84 | } | |
85 | list = loptend; | |
86 | ||
87 | if (list == 0) | |
88 | { | |
89 | builtin_usage (); | |
90 | return (EX_USAGE); | |
91 | } | |
92 | ||
93 | linkfn = (flags & LN_SYMLINK) ? symlink : link; | |
94 | ||
95 | if (list->next == 0) /* ln target, equivalent to ln target . */ | |
96 | return (dolink (list->word->word, ".", flags)); | |
97 | ||
98 | if (list->next->next == 0) /* ln target source */ | |
99 | return (dolink (list->word->word, list->next->word->word, flags)); | |
100 | ||
101 | /* ln target1 target2 ... directory */ | |
102 | ||
103 | /* find last argument: target directory, and make sure it's an existing | |
104 | directory. */ | |
105 | for (l = list; l->next; l = l->next) | |
106 | ; | |
107 | sdir = l->word->word; | |
108 | ||
109 | if (stat(sdir, &sb) < 0) | |
110 | { | |
111 | builtin_error ("%s", sdir); | |
112 | return (EXECUTION_FAILURE); | |
113 | } | |
114 | ||
115 | if (S_ISDIR (sb.st_mode) == 0) | |
116 | { | |
117 | builtin_usage (); | |
118 | return (EX_USAGE); | |
119 | } | |
120 | ||
121 | for (rval = EXECUTION_SUCCESS; list != l; list = list->next) | |
122 | rval += dolink (list->word->word, sdir, flags); | |
123 | ||
124 | return rval; | |
125 | } | |
126 | ||
127 | static char * | |
128 | mkdirpath (dir, file) | |
129 | char *dir, *file; | |
130 | { | |
131 | int dlen, flen; | |
132 | char *ret; | |
133 | ||
134 | dlen = strlen (dir); | |
135 | flen = strlen (file); | |
136 | ||
137 | ret = xmalloc (2 + dlen + flen); | |
138 | ||
139 | strcpy (ret, dir); | |
140 | if (ret[dlen - 1] != '/') | |
141 | ret[dlen++] = '/'; | |
142 | strcpy (ret + dlen, file); | |
143 | return ret; | |
144 | } | |
145 | ||
146 | #if defined (HAVE_LSTAT) | |
147 | # define LSTAT lstat | |
a0c0a00f | 148 | # define LSTAT_OR_STAT_IF(c, f, b) ((c) ? lstat((f), (b)) : stat((f), (b))) |
b72432fd JA |
149 | #else |
150 | # define LSTAT stat | |
a0c0a00f | 151 | # define LSTAT_OR_STAT_IF(c, f, b) (stat((f), (b))) |
b72432fd JA |
152 | #endif |
153 | ||
154 | static int | |
155 | dolink (src, dst, flags) | |
156 | char *src, *dst; | |
157 | int flags; | |
158 | { | |
159 | struct stat ssb, dsb; | |
160 | int exists; | |
161 | char *dst_path, *p; | |
162 | ||
163 | /* If we're not doing symlinks, the source must exist and not be a | |
164 | directory. */ | |
165 | if ((flags & LN_SYMLINK) == 0) | |
166 | { | |
167 | if (stat (src, &ssb) != 0) | |
168 | { | |
169 | builtin_error ("%s: %s", src, strerror (errno)); | |
170 | return (EXECUTION_FAILURE); | |
171 | } | |
172 | if (S_ISDIR (ssb.st_mode)) | |
173 | { | |
174 | errno = EISDIR; | |
175 | builtin_error ("%s: %s", src, strerror (errno)); | |
176 | return (EXECUTION_FAILURE); | |
177 | } | |
178 | } | |
179 | ||
180 | /* If the destination is a directory, create the final filename by appending | |
181 | the basename of the source to the destination. */ | |
182 | dst_path = 0; | |
a0c0a00f | 183 | if ((LSTAT_OR_STAT_IF((flags & LN_NOFOLLOW), dst, &dsb) == 0) && S_ISDIR (dsb.st_mode)) |
b72432fd JA |
184 | { |
185 | if ((p = strrchr (src, '/')) == 0) | |
186 | p = src; | |
187 | else | |
188 | p++; | |
189 | ||
190 | dst_path = mkdirpath (dst, p); | |
191 | dst = dst_path; | |
192 | } | |
193 | ||
194 | exists = LSTAT (dst, &dsb) == 0; | |
195 | ||
196 | /* If -f was specified, and the destination exists, unlink it. */ | |
197 | if ((flags & LN_UNLINK) && exists && unlink (dst) != 0) | |
198 | { | |
199 | builtin_error ("%s: cannot unlink: %s", dst, strerror (errno)); | |
200 | FREE (dst_path); | |
201 | return (EXECUTION_FAILURE); | |
202 | } | |
203 | ||
204 | /* Perform the link. */ | |
205 | if ((*linkfn) (src, dst) != 0) | |
206 | { | |
207 | builtin_error ("cannot link %s to %s: %s", dst, src, strerror (errno)); | |
208 | FREE (dst_path); | |
209 | return (EXECUTION_FAILURE); | |
210 | } | |
211 | ||
212 | FREE (dst_path); | |
213 | return (EXECUTION_SUCCESS); | |
214 | } | |
215 | ||
216 | char *ln_doc[] = { | |
3185942a JA |
217 | "Link files.", |
218 | "", | |
b72432fd JA |
219 | "Create a new directory entry with the same modes as the original", |
220 | "file. The -f option means to unlink any existing file, permitting", | |
221 | "the link to occur. The -s option means to create a symbolic link.", | |
a0c0a00f CR |
222 | "By default, ln makes hard links. Specifying -n or its synonym -h", |
223 | "causes ln to not resolve symlinks in the target file or directory.", | |
b72432fd JA |
224 | (char *)NULL |
225 | }; | |
226 | ||
227 | /* The standard structure describing a builtin command. bash keeps an array | |
228 | of these structures. */ | |
229 | struct builtin ln_struct = { | |
230 | "ln", /* builtin name */ | |
231 | ln_builtin, /* function implementing the builtin */ | |
232 | BUILTIN_ENABLED, /* initial flags for builtin */ | |
233 | ln_doc, /* array of long documentation strings. */ | |
a0c0a00f | 234 | "ln [-fhns] file1 [file2] OR ln [-fhns] file ... directory", /* usage synopsis; becomes short_doc */ |
b72432fd JA |
235 | 0 /* reserved for internal use */ |
236 | }; |