overby.me
this repo has no description
1/*-
2 * Copyright (c) 1987, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 * may be used to endorse or promote products derived from this software
15 * without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#if 0
31#ifndef lint
32static char const copyright[] =
33"@(#) Copyright (c) 1987, 1993, 1994\n\
34 The Regents of the University of California. All rights reserved.\n";
35#endif /* not lint */
36
37#ifndef lint
38static char sccsid[] = "@(#)ln.c 8.2 (Berkeley) 3/31/94";
39#endif /* not lint */
40#endif
41#include <sys/cdefs.h>
42//__FBSDID("$FreeBSD: src/bin/ln/ln.c,v 1.34 2006/02/14 11:08:05 glebius Exp $");
43
44#include <bsd/string.h>
45
46#include <sys/param.h>
47#include <sys/stat.h>
48
49#include <err.h>
50#include <errno.h>
51#include <libgen.h>
52#include <limits.h>
53#include <stdio.h>
54#include <stdlib.h>
55#include <string.h>
56#include <unistd.h>
57
58int fflag; /* Unlink existing files. */
59int Fflag; /* Remove empty directories also. */
60int hflag; /* Check new name for symlink first. */
61int iflag; /* Interactive mode. */
62int sflag; /* Symbolic, not hard, link. */
63int vflag; /* Verbose output. */
64 /* System link call. */
65int (*linkf)(const char *, const char *);
66char linkch;
67
68int linkit(const char *, const char *, int);
69void usage(void);
70
71int
72main(int argc, char *argv[])
73{
74 struct stat sb;
75 char *p, *sourcedir;
76 int ch, exitval;
77
78 if (argc < 1)
79 usage();
80 /*
81 * Test for the special case where the utility is called as
82 * "link", for which the functionality provided is greatly
83 * simplified.
84 */
85 if ((p = rindex(argv[0], '/')) == NULL)
86 p = argv[0];
87 else
88 ++p;
89 if (strcmp(p, "link") == 0) {
90 while (getopt(argc, argv, "") != -1)
91 usage();
92 argc -= optind;
93 argv += optind;
94 if (argc != 2)
95 usage();
96 linkf = link;
97 exit(linkit(argv[0], argv[1], 0));
98 }
99
100 while ((ch = getopt(argc, argv, "Ffhinsv")) != -1)
101 switch (ch) {
102 case 'F':
103 Fflag = 1;
104 break;
105 case 'f':
106 fflag = 1;
107 iflag = 0;
108 break;
109 case 'h':
110 case 'n':
111 hflag = 1;
112 break;
113 case 'i':
114 iflag = 1;
115 fflag = 0;
116 break;
117 case 's':
118 sflag = 1;
119 break;
120 case 'v':
121 vflag = 1;
122 break;
123 case '?':
124 default:
125 usage();
126 }
127
128 argv += optind;
129 argc -= optind;
130
131 linkf = sflag ? symlink : link;
132 linkch = sflag ? '-' : '=';
133 if (sflag == 0)
134 Fflag = 0;
135 if (Fflag == 1 && iflag == 0)
136 fflag = 1;
137
138 switch(argc) {
139 case 0:
140 usage();
141 /* NOTREACHED */
142 case 1: /* ln target */
143 exit(linkit(argv[0], ".", 1));
144 case 2: /* ln target source */
145 exit(linkit(argv[0], argv[1], 0));
146 default:
147 ;
148 }
149 /* ln target1 target2 directory */
150 sourcedir = argv[argc - 1];
151 if (hflag && lstat(sourcedir, &sb) == 0 && S_ISLNK(sb.st_mode)) {
152 /*
153 * We were asked not to follow symlinks, but found one at
154 * the target--simulate "not a directory" error
155 */
156 errno = ENOTDIR;
157 err(1, "%s", sourcedir);
158 }
159 if (stat(sourcedir, &sb))
160 err(1, "%s", sourcedir);
161 if (!S_ISDIR(sb.st_mode))
162 usage();
163 for (exitval = 0; *argv != sourcedir; ++argv)
164 exitval |= linkit(*argv, sourcedir, 1);
165 exit(exitval);
166}
167
168int
169linkit(const char *target, const char *source, int isdir)
170{
171 struct stat sb;
172 const char *p;
173 int ch, exists, first;
174 char path[PATH_MAX];
175 char bbuf[PATH_MAX];
176
177 if (!sflag) {
178 /* If target doesn't exist, quit now. */
179 if (stat(target, &sb)) {
180 warn("%s", target);
181 return (1);
182 }
183 /* Only symbolic links to directories. */
184 if (S_ISDIR(sb.st_mode)) {
185 errno = EISDIR;
186 warn("%s", target);
187 return (1);
188 }
189 }
190
191 /*
192 * If the source is a directory (and not a symlink if hflag),
193 * append the target's name.
194 */
195 if (isdir ||
196 (lstat(source, &sb) == 0 && S_ISDIR(sb.st_mode)) ||
197 (!hflag && stat(source, &sb) == 0 && S_ISDIR(sb.st_mode))) {
198 if (strlcpy(bbuf, target, sizeof(bbuf)) >= sizeof(bbuf) ||
199 (p = basename(bbuf)) == NULL ||
200 snprintf(path, sizeof(path), "%s/%s", source, p) >=
201 (ssize_t)sizeof(path)) {
202 errno = ENAMETOOLONG;
203 warn("%s", target);
204 return (1);
205 }
206 source = path;
207 }
208
209 exists = !lstat(source, &sb);
210 /*
211 * If the file exists, then unlink it forcibly if -f was specified
212 * and interactively if -i was specified.
213 */
214 if (fflag && exists) {
215 if (Fflag && S_ISDIR(sb.st_mode)) {
216 if (rmdir(source)) {
217 warn("%s", source);
218 return (1);
219 }
220 } else if (unlink(source)) {
221 warn("%s", source);
222 return (1);
223 }
224 } else if (iflag && exists) {
225 fflush(stdout);
226 fprintf(stderr, "replace %s? ", source);
227
228 first = ch = getchar();
229 while(ch != '\n' && ch != EOF)
230 ch = getchar();
231 if (first != 'y' && first != 'Y') {
232 fprintf(stderr, "not replaced\n");
233 return (1);
234 }
235
236 if (Fflag && S_ISDIR(sb.st_mode)) {
237 if (rmdir(source)) {
238 warn("%s", source);
239 return (1);
240 }
241 } else if (unlink(source)) {
242 warn("%s", source);
243 return (1);
244 }
245 }
246
247 /* Attempt the link. */
248 if ((*linkf)(target, source)) {
249 warn("%s", source);
250 return (1);
251 }
252 if (vflag)
253 (void)printf("%s %c> %s\n", source, linkch, target);
254 return (0);
255}
256
257void
258usage(void)
259{
260 (void)fprintf(stderr, "%s\n%s\n%s\n",
261 "usage: ln [-Ffhinsv] source_file [target_file]",
262 " ln [-Ffhinsv] source_file ... target_dir",
263 " link source_file target_file");
264 exit(1);
265}