1 /* $NetBSD: ln.c,v 1.35 2011/08/29 14:38:30 joerg Exp $ */
2
3 /*
4 * Copyright (c) 1987, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1987, 1993, 1994\
35 The Regents of the University of California. All rights reserved.");
36 #endif /* not lint */
37
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)ln.c 8.2 (Berkeley) 3/31/94";
41 #else
42 __RCSID("$NetBSD: ln.c,v 1.35 2011/08/29 14:38:30 joerg Exp $");
43 #endif
44 #endif /* not lint */
45
46 #include <sys/param.h>
47 #include <sys/stat.h>
48
49 #include <err.h>
50 #include <errno.h>
51 #include <locale.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <unistd.h>
56
57 static int fflag; /* Unlink existing files. */
58 static int hflag; /* Check new name for symlink first. */
59 static int iflag; /* Interactive mode. */
60 static int sflag; /* Symbolic, not hard, link. */
61 static int vflag; /* Verbose output */
62
63 /* System link call. */
64 static int (*linkf)(const char *, const char *);
65 static char linkch;
66
67 static int linkit(const char *, const char *, int);
68 __dead static void usage(void);
69
70 int
main(int argc,char * argv[])71 main(int argc, char *argv[])
72 {
73 struct stat sb;
74 int ch, exitval;
75 char *sourcedir;
76
77 setprogname(argv[0]);
78 (void)setlocale(LC_ALL, "");
79
80 while ((ch = getopt(argc, argv, "fhinsv")) != -1)
81 switch (ch) {
82 case 'f':
83 fflag = 1;
84 iflag = 0;
85 break;
86 case 'h':
87 case 'n':
88 hflag = 1;
89 break;
90 case 'i':
91 iflag = 1;
92 fflag = 0;
93 break;
94 case 's':
95 sflag = 1;
96 break;
97 case 'v':
98 vflag = 1;
99 break;
100 case '?':
101 default:
102 usage();
103 /* NOTREACHED */
104 }
105
106 argv += optind;
107 argc -= optind;
108
109 if (sflag) {
110 linkf = symlink;
111 linkch = '-';
112 } else {
113 linkf = link;
114 linkch = '=';
115 }
116
117 switch(argc) {
118 case 0:
119 usage();
120 /* NOTREACHED */
121 case 1: /* ln target */
122 exit(linkit(argv[0], ".", 1));
123 /* NOTREACHED */
124 case 2: /* ln target source */
125 exit(linkit(argv[0], argv[1], 0));
126 /* NOTREACHED */
127 }
128
129 /* ln target1 target2 directory */
130 sourcedir = argv[argc - 1];
131 if (hflag && lstat(sourcedir, &sb) == 0 && S_ISLNK(sb.st_mode)) {
132 /* we were asked not to follow symlinks, but found one at
133 the target--simulate "not a directory" error */
134 errno = ENOTDIR;
135 err(EXIT_FAILURE, "%s", sourcedir);
136 /* NOTREACHED */
137 }
138 if (stat(sourcedir, &sb)) {
139 err(EXIT_FAILURE, "%s", sourcedir);
140 /* NOTREACHED */
141 }
142 if (!S_ISDIR(sb.st_mode)) {
143 usage();
144 /* NOTREACHED */
145 }
146 for (exitval = 0; *argv != sourcedir; ++argv)
147 exitval |= linkit(*argv, sourcedir, 1);
148 exit(exitval);
149 /* NOTREACHED */
150 }
151
152 static int
linkit(const char * target,const char * source,int isdir)153 linkit(const char *target, const char *source, int isdir)
154 {
155 struct stat sb;
156 const char *p;
157 char path[MAXPATHLEN];
158 int ch, exists, first;
159
160 if (!sflag) {
161 /* If target doesn't exist, quit now. */
162 if (stat(target, &sb)) {
163 warn("%s", target);
164 return (1);
165 }
166 }
167
168 /* If the source is a directory (and not a symlink if hflag),
169 append the target's name. */
170 if (isdir ||
171 (!lstat(source, &sb) && S_ISDIR(sb.st_mode)) ||
172 (!hflag && !stat(source, &sb) && S_ISDIR(sb.st_mode))) {
173 if ((p = strrchr(target, '/')) == NULL)
174 p = target;
175 else
176 ++p;
177 (void)snprintf(path, sizeof(path), "%s/%s", source, p);
178 source = path;
179 }
180
181 exists = !lstat(source, &sb);
182
183 /*
184 * If the file exists, then unlink it forcibly if -f was specified
185 * and interactively if -i was specified.
186 */
187 if (fflag && exists) {
188 if (unlink(source)) {
189 warn("%s", source);
190 return (1);
191 }
192 } else if (iflag && exists) {
193 fflush(stdout);
194 (void)fprintf(stderr, "replace %s? ", source);
195
196 first = ch = getchar();
197 while (ch != '\n' && ch != EOF)
198 ch = getchar();
199 if (first != 'y' && first != 'Y') {
200 (void)fprintf(stderr, "not replaced\n");
201 return (1);
202 }
203
204 if (unlink(source)) {
205 warn("%s", source);
206 return (1);
207 }
208 }
209
210 /* Attempt the link. */
211 if ((*linkf)(target, source)) {
212 warn("%s", source);
213 return (1);
214 }
215 if (vflag)
216 (void)printf("%s %c> %s\n", source, linkch, target);
217
218 return (0);
219 }
220
221 static void
usage(void)222 usage(void)
223 {
224
225 (void)fprintf(stderr,
226 "usage:\t%s [-fhinsv] file1 file2\n\t%s [-fhinsv] file ... directory\n",
227 getprogname(), getprogname());
228 exit(1);
229 /* NOTREACHED */
230 }
231