ln/ln.c

   1 /*      $NetBSD: ln.c,v 1.15 1998/07/28 05:31:25 mycroft 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. All advertising materials mentioning features or use of this software
  16  *    must display the following acknowledgement:
  17  *      This product includes software developed by the University of
  18  *      California, Berkeley and its contributors.
  19  * 4. Neither the name of the University nor the names of its contributors
  20  *    may be used to endorse or promote products derived from this software
  21  *    without specific prior written permission.
  22  *
  23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  33  * SUCH DAMAGE.
  34  */
  35
  36 #include <sys/cdefs.h>
  37 #ifndef lint
  38 __COPYRIGHT("@(#) Copyright (c) 1987, 1993, 1994\n\
  39         The Regents of the University of California.  All rights reserved.\n");
  40 #endif /* not lint */
  41
  42 #ifndef lint
  43 #if 0
  44 static char sccsid[] = "@(#)ln.c        8.2 (Berkeley) 3/31/94";
  45 #else
  46 __RCSID("$NetBSD: ln.c,v 1.15 1998/07/28 05:31:25 mycroft Exp $");
  47 #endif
  48 #endif /* not lint */
  49
  50 #include <sys/param.h>
  51 #include <sys/stat.h>
  52
  53 #include <err.h>
  54 #include <errno.h>
  55 #include <stdio.h>
  56 #include <stdlib.h>
  57 #include <string.h>
  58 #include <unistd.h>
  59
  60 int     fflag;                          /* Unlink existing files. */
  61 int     hflag;                          /* Check new name for symlink first. */
  62 int     sflag;                          /* Symbolic, not hard, link. */
  63                                         /* System link call. */
  64 int (*linkf) __P((const char *, const char *));
  65
  66 int     linkit __P((char *, char *, int));
  67 void    usage __P((void));
  68 int     main __P((int, char *[]));
  69
  70 int
  71 main(argc, argv)
  72         int argc;
  73         char *argv[];
  74 {
  75         struct stat sb;
  76         int ch, exitval;
  77         char *sourcedir;
  78
  79         while ((ch = getopt(argc, argv, "fhns")) != -1)
  80                 switch (ch) {
  81                 case 'f':
  82                         fflag = 1;
  83                         break;
  84                 case 'h':
  85                 case 'n':
  86                         hflag = 1;
  87                         break;
  88                 case 's':
  89                         sflag = 1;
  90                         break;
  91                 case '?':
  92                 default:
  93                         usage();
  94                 }
  95
  96         argv += optind;
  97         argc -= optind;
  98
  99         linkf = sflag ? symlink : link;
 100
 101         switch(argc) {
 102         case 0:
 103                 usage();
 104                 /* NOTREACHED */
 105         case 1:                         /* ln target */
 106                 exit(linkit(argv[0], ".", 1));
 107                 /* NOTREACHED */
 108         case 2:                         /* ln target source */
 109                 exit(linkit(argv[0], argv[1], 0));
 110                 /* NOTREACHED */
 111         }
 112                                         /* ln target1 target2 directory */
 113         sourcedir = argv[argc - 1];
 114         if (hflag && lstat(sourcedir, &sb) == 0 && S_ISLNK(sb.st_mode)) {
 115                 /* we were asked not to follow symlinks, but found one at
 116                    the target--simulate "not a directory" error */
 117                 errno = ENOTDIR;
 118                 err(1, "%s", sourcedir);
 119         }
 120         if (stat(sourcedir, &sb))
 121                 err(1, "%s", sourcedir);
 122         if (!S_ISDIR(sb.st_mode))
 123                 usage();
 124         for (exitval = 0; *argv != sourcedir; ++argv)
 125                 exitval |= linkit(*argv, sourcedir, 1);
 126         exit(exitval);
 127         /* NOTREACHED */
 128 }
 129
 130 int
 131 linkit(target, source, isdir)
 132         char *target, *source;
 133         int isdir;
 134 {
 135         struct stat sb;
 136         char *p, path[MAXPATHLEN];
 137
 138         if (!sflag) {
 139                 /* If target doesn't exist, quit now. */
 140                 if (stat(target, &sb)) {
 141                         warn("%s", target);
 142                         return (1);
 143                 }
 144         }
 145
 146         /* If the source is a directory (and not a symlink if hflag),
 147            append the target's name. */
 148         if (isdir ||
 149             (!lstat(source, &sb) && S_ISDIR(sb.st_mode)) ||
 150             (!hflag && !stat(source, &sb) && S_ISDIR(sb.st_mode))) {
 151                 if ((p = strrchr(target, '/')) == NULL)
 152                         p = target;
 153                 else
 154                         ++p;
 155                 (void)snprintf(path, sizeof(path), "%s/%s", source, p);
 156                 source = path;
 157         }
 158
 159         /*
 160          * If the file exists, and -f was specified, unlink it.
 161          * Attempt the link.
 162          */
 163         if ((fflag && unlink(source) < 0 && errno != ENOENT) ||
 164             (*linkf)(target, source)) {
 165                 warn("%s", source);
 166                 return (1);
 167         }
 168
 169         return (0);
 170 }
 171
 172 void
 173 usage()
 174 {
 175
 176         extern char *__progname;
 177         (void)fprintf(stderr,
 178             "Usage:\t%s [-fhns] file1 file2\n\t%s [-fhns] file ... directory\n",
 179             __progname, __progname);
 180         exit(1);
 181         /* NOTREACHED */
 182 }