| 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 |
| 32 | static 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 |
| 38 | static 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 <sys/param.h> |
| 45 | #include <sys/stat.h> |
| 46 | |
| 47 | #include <err.h> |
| 48 | #include <errno.h> |
| 49 | #include <libgen.h> |
| 50 | #include <limits.h> |
| 51 | #include <stdio.h> |
| 52 | #include <stdlib.h> |
| 53 | #include <string.h> |
| 54 | #include <unistd.h> |
| 55 | |
| 56 | int fflag; /* Unlink existing files. */ |
| 57 | int Fflag; /* Remove empty directories also. */ |
| 58 | int hflag; /* Check new name for symlink first. */ |
| 59 | int iflag; /* Interactive mode. */ |
| 60 | int sflag; /* Symbolic, not hard, link. */ |
| 61 | int vflag; /* Verbose output. */ |
| 62 | /* System link call. */ |
| 63 | int (*linkf)(const char *, const char *); |
| 64 | char linkch; |
| 65 | |
| 66 | int linkit(const char *, const char *, int); |
| 67 | void usage(void); |
| 68 | |
| 69 | int |
| 70 | main(int argc, char *argv[]) |
| 71 | { |
| 72 | struct stat sb; |
| 73 | char *p, *sourcedir; |
| 74 | int ch, exitval; |
| 75 | |
| 76 | if (argc < 1) |
| 77 | usage(); |
| 78 | /* |
| 79 | * Test for the special case where the utility is called as |
| 80 | * "link", for which the functionality provided is greatly |
| 81 | * simplified. |
| 82 | */ |
| 83 | if ((p = rindex(argv[0], '/')) == NULL) |
| 84 | p = argv[0]; |
| 85 | else |
| 86 | ++p; |
| 87 | if (strcmp(p, "link") == 0) { |
| 88 | while (getopt(argc, argv, "") != -1) |
| 89 | usage(); |
| 90 | argc -= optind; |
| 91 | argv += optind; |
| 92 | if (argc != 2) |
| 93 | usage(); |
| 94 | linkf = link; |
| 95 | /* UNIX conformance requires that both operands be NOT a dir */ |
| 96 | for (int i = 0; i < 2; i++) { |
| 97 | if (stat(argv[i], &sb) == 0 && S_ISDIR(sb.st_mode)){ |
| 98 | errno = EISDIR; |
| 99 | warn("%s", argv[0]); |
| 100 | return 1; |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | exit(linkit(argv[0], argv[1], 0)); |
| 105 | } |
| 106 | |
| 107 | while ((ch = getopt(argc, argv, "Ffhinsv")) != -1) |
| 108 | switch (ch) { |
| 109 | case 'F': |
| 110 | Fflag = 1; |
| 111 | break; |
| 112 | case 'f': |
| 113 | fflag = 1; |
| 114 | iflag = 0; |
| 115 | break; |
| 116 | case 'h': |
| 117 | case 'n': |
| 118 | hflag = 1; |
| 119 | break; |
| 120 | case 'i': |
| 121 | iflag = 1; |
| 122 | fflag = 0; |
| 123 | break; |
| 124 | case 's': |
| 125 | sflag = 1; |
| 126 | break; |
| 127 | case 'v': |
| 128 | vflag = 1; |
| 129 | break; |
| 130 | case '?': |
| 131 | default: |
| 132 | usage(); |
| 133 | } |
| 134 | |
| 135 | argv += optind; |
| 136 | argc -= optind; |
| 137 | |
| 138 | linkf = sflag ? symlink : link; |
| 139 | linkch = sflag ? '-' : '='; |
| 140 | if (sflag == 0) |
| 141 | Fflag = 0; |
| 142 | if (Fflag == 1 && iflag == 0) |
| 143 | fflag = 1; |
| 144 | |
| 145 | switch(argc) { |
| 146 | case 0: |
| 147 | usage(); |
| 148 | /* NOTREACHED */ |
| 149 | case 1: /* ln target */ |
| 150 | exit(linkit(argv[0], ".", 1)); |
| 151 | case 2: /* ln target source */ |
| 152 | exit(linkit(argv[0], argv[1], 0)); |
| 153 | default: |
| 154 | ; |
| 155 | } |
| 156 | /* ln target1 target2 directory */ |
| 157 | sourcedir = argv[argc - 1]; |
| 158 | if (hflag && lstat(sourcedir, &sb) == 0 && S_ISLNK(sb.st_mode)) { |
| 159 | /* |
| 160 | * We were asked not to follow symlinks, but found one at |
| 161 | * the target--simulate "not a directory" error |
| 162 | */ |
| 163 | errno = ENOTDIR; |
| 164 | err(1, "%s", sourcedir); |
| 165 | } |
| 166 | if (stat(sourcedir, &sb)) |
| 167 | err(1, "%s", sourcedir); |
| 168 | if (!S_ISDIR(sb.st_mode)) |
| 169 | usage(); |
| 170 | for (exitval = 0; *argv != sourcedir; ++argv) |
| 171 | exitval |= linkit(*argv, sourcedir, 1); |
| 172 | exit(exitval); |
| 173 | } |
| 174 | |
| 175 | int |
| 176 | linkit(const char *target, const char *source, int isdir) |
| 177 | { |
| 178 | struct stat sb; |
| 179 | const char *p; |
| 180 | int ch, exists, first; |
| 181 | char path[PATH_MAX]; |
| 182 | char bbuf[PATH_MAX]; |
| 183 | |
| 184 | if (!sflag) { |
| 185 | /* If target doesn't exist, quit now. */ |
| 186 | if (stat(target, &sb)) { |
| 187 | warn("%s", target); |
| 188 | return (1); |
| 189 | } |
| 190 | /* Only symbolic links to directories. */ |
| 191 | if (S_ISDIR(sb.st_mode)) { |
| 192 | errno = EISDIR; |
| 193 | warn("%s", target); |
| 194 | return (1); |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | /* |
| 199 | * If the source is a directory (and not a symlink if hflag), |
| 200 | * append the target's name. |
| 201 | */ |
| 202 | if (isdir || |
| 203 | (lstat(source, &sb) == 0 && S_ISDIR(sb.st_mode)) || |
| 204 | (!hflag && stat(source, &sb) == 0 && S_ISDIR(sb.st_mode))) { |
| 205 | if (strlcpy(bbuf, target, sizeof(bbuf)) >= sizeof(bbuf) || |
| 206 | (p = basename(bbuf)) == NULL || |
| 207 | snprintf(path, sizeof(path), "%s/%s", source, p) >= |
| 208 | (ssize_t)sizeof(path)) { |
| 209 | errno = ENAMETOOLONG; |
| 210 | warn("%s", target); |
| 211 | return (1); |
| 212 | } |
| 213 | source = path; |
| 214 | } |
| 215 | |
| 216 | exists = !lstat(source, &sb); |
| 217 | /* |
| 218 | * If the file exists, then unlink it forcibly if -f was specified |
| 219 | * and interactively if -i was specified. |
| 220 | */ |
| 221 | if (fflag && exists) { |
| 222 | if (Fflag && S_ISDIR(sb.st_mode)) { |
| 223 | if (rmdir(source)) { |
| 224 | warn("%s", source); |
| 225 | return (1); |
| 226 | } |
| 227 | } else if (unlink(source)) { |
| 228 | warn("%s", source); |
| 229 | return (1); |
| 230 | } |
| 231 | } else if (iflag && exists) { |
| 232 | fflush(stdout); |
| 233 | fprintf(stderr, "replace %s? ", source); |
| 234 | |
| 235 | first = ch = getchar(); |
| 236 | while(ch != '\n' && ch != EOF) |
| 237 | ch = getchar(); |
| 238 | if (first != 'y' && first != 'Y') { |
| 239 | fprintf(stderr, "not replaced\n"); |
| 240 | return (1); |
| 241 | } |
| 242 | |
| 243 | if (Fflag && S_ISDIR(sb.st_mode)) { |
| 244 | if (rmdir(source)) { |
| 245 | warn("%s", source); |
| 246 | return (1); |
| 247 | } |
| 248 | } else if (unlink(source)) { |
| 249 | warn("%s", source); |
| 250 | return (1); |
| 251 | } |
| 252 | } |
| 253 | |
| 254 | /* Attempt the link. */ |
| 255 | if ((*linkf)(target, source)) { |
| 256 | warn("%s", source); |
| 257 | return (1); |
| 258 | } |
| 259 | if (vflag) |
| 260 | (void)printf("%s %c> %s\n", source, linkch, target); |
| 261 | return (0); |
| 262 | } |
| 263 | |
| 264 | void |
| 265 | usage(void) |
| 266 | { |
| 267 | (void)fprintf(stderr, "%s\n%s\n%s\n", |
| 268 | "usage: ln [-Ffhinsv] source_file [link_name]", |
| 269 | " ln [-Ffhinsv] source_file ... linkname_dir", |
| 270 | " link source_file link_name"); |
| 271 | exit(1); |
| 272 | } |