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 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 * 33 * @(#) Copyright (c) 1987, 1993, 1994 The Regents of the University of California. All rights reserved. 34 * @(#)ln.c 8.2 (Berkeley) 3/31/94 35 * $FreeBSD: src/bin/ln/ln.c,v 1.15.2.4 2002/07/12 07:34:38 tjr Exp $ 36 * $DragonFly: src/bin/ln/ln.c,v 1.5 2004/11/07 20:54:51 eirikn Exp $ 37 */ 38 39 #include <sys/param.h> 40 #include <sys/stat.h> 41 42 #include <err.h> 43 #include <errno.h> 44 #include <limits.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <unistd.h> 49 50 int fflag; /* Unlink existing files. */ 51 int hflag; /* Check new name for symlink first. */ 52 int iflag; /* Interactive mode. */ 53 int sflag; /* Symbolic, not hard, link. */ 54 int vflag; /* Verbose output. */ 55 /* System link call. */ 56 int (*linkf)(const char *, const char *); 57 char linkch; 58 59 int linkit(const char *, const char *, int); 60 void usage(void); 61 62 int 63 main(int argc, char *argv[]) 64 { 65 struct stat sb; 66 char *p, *sourcedir; 67 int ch, exitval; 68 69 /* 70 * Test for the special case where the utility is called as 71 * "link", for which the functionality provided is greatly 72 * simplified. 73 */ 74 if ((p = strrchr(argv[0], '/')) == NULL) 75 p = argv[0]; 76 else 77 ++p; 78 if (strcmp(p, "link") == 0) { 79 while (getopt(argc, argv, "") != -1) 80 usage(); 81 argc -= optind; 82 argv += optind; 83 if (argc != 2) 84 usage(); 85 linkf = link; 86 exit(linkit(argv[0], argv[1], 0)); 87 } 88 89 while ((ch = getopt(argc, argv, "fhinsv")) != -1) 90 switch (ch) { 91 case 'f': 92 fflag = 1; 93 iflag = 0; 94 break; 95 case 'h': 96 case 'n': 97 hflag = 1; 98 break; 99 case 'i': 100 iflag = 1; 101 fflag = 0; 102 break; 103 case 's': 104 sflag = 1; 105 break; 106 case 'v': 107 vflag = 1; 108 break; 109 case '?': 110 default: 111 usage(); 112 } 113 114 argv += optind; 115 argc -= optind; 116 117 linkf = sflag ? symlink : link; 118 linkch = sflag ? '-' : '='; 119 120 switch(argc) { 121 case 0: 122 usage(); 123 /* NOTREACHED */ 124 case 1: /* ln target */ 125 exit(linkit(argv[0], ".", 1)); 126 case 2: /* ln target source */ 127 exit(linkit(argv[0], argv[1], 0)); 128 default: 129 ; 130 } 131 /* ln target1 target2 directory */ 132 sourcedir = argv[argc - 1]; 133 if (hflag && lstat(sourcedir, &sb) == 0 && S_ISLNK(sb.st_mode)) { 134 /* 135 * We were asked not to follow symlinks, but found one at 136 * the target--simulate "not a directory" error 137 */ 138 errno = ENOTDIR; 139 err(1, "%s", sourcedir); 140 } 141 if (stat(sourcedir, &sb)) 142 err(1, "%s", sourcedir); 143 if (!S_ISDIR(sb.st_mode)) 144 usage(); 145 for (exitval = 0; *argv != sourcedir; ++argv) 146 exitval |= linkit(*argv, sourcedir, 1); 147 exit(exitval); 148 } 149 150 int 151 linkit(const char *target, const char *source, int isdir) 152 { 153 struct stat sb; 154 const char *p; 155 int ch, exists, first; 156 char path[PATH_MAX]; 157 158 if (!sflag) { 159 /* If target doesn't exist, quit now. */ 160 if (stat(target, &sb)) { 161 warn("%s", target); 162 return (1); 163 } 164 /* Only symbolic links to directories. */ 165 if (S_ISDIR(sb.st_mode)) { 166 errno = EISDIR; 167 warn("%s", target); 168 return (1); 169 } 170 } 171 172 /* 173 * If the source is a directory (and not a symlink if hflag), 174 * append the target's name. 175 */ 176 if (isdir || 177 (lstat(source, &sb) == 0 && S_ISDIR(sb.st_mode)) || 178 (!hflag && stat(source, &sb) == 0 && S_ISDIR(sb.st_mode))) { 179 if ((p = strrchr(target, '/')) == NULL) 180 p = target; 181 else 182 ++p; 183 if (snprintf(path, sizeof(path), "%s/%s", source, p) >= 184 (int)sizeof(path)) { 185 errno = ENAMETOOLONG; 186 warn("%s", target); 187 return (1); 188 } 189 source = path; 190 } 191 192 exists = !lstat(source, &sb); 193 /* 194 * If the file exists, then unlink it forcibly if -f was specified 195 * and interactively if -i was specified. 196 */ 197 if (fflag && exists) { 198 if (unlink(source)) { 199 warn("%s", source); 200 return (1); 201 } 202 } else if (iflag && exists) { 203 fflush(stdout); 204 fprintf(stderr, "replace %s? ", source); 205 206 first = ch = getchar(); 207 while(ch != '\n' && ch != EOF) 208 ch = getchar(); 209 if (first != 'y' && first != 'Y') { 210 fprintf(stderr, "not replaced\n"); 211 return (1); 212 } 213 214 if (unlink(source)) { 215 warn("%s", source); 216 return (1); 217 } 218 } 219 220 /* Attempt the link. */ 221 if ((*linkf)(target, source)) { 222 warn("%s", source); 223 return (1); 224 } 225 if (vflag) 226 printf("%s %c> %s\n", source, linkch, target); 227 return (0); 228 } 229 230 void 231 usage(void) 232 { 233 fprintf(stderr, "%s\n%s\n%s\n", 234 "usage: ln [-fhinsv] file1 file2", 235 " ln [-fhinsv] file ... directory", 236 " link file1 file2"); 237 exit(1); 238 } 239