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ln.c revision 1.10 
      1 /*	$NetBSD: ln.c,v 1.10 1995/03/21 09:06:10 cgd 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 #ifndef lint
     37 static char copyright[] =
     38 "@(#) 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 static char rcsid[] = "$NetBSD: ln.c,v 1.10 1995/03/21 09:06:10 cgd 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	dirflag;			/* Undocumented directory flag. */
     61 int	fflag;				/* Unlink existing files. */
     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 
     69 int
     70 main(argc, argv)
     71 	int argc;
     72 	char *argv[];
     73 {
     74 	struct stat sb;
     75 	int ch, exitval;
     76 	char *sourcedir;
     77 
     78 	while ((ch = getopt(argc, argv, "Ffs")) != -1)
     79 		switch (ch) {
     80 		case 'F':
     81 			dirflag = 1;	/* XXX: deliberately undocumented. */
     82 			break;
     83 		case 'f':
     84 			fflag = 1;
     85 			break;
     86 		case 's':
     87 			sflag = 1;
     88 			break;
     89 		case '?':
     90 		default:
     91 			usage();
     92 		}
     93 
     94 	argv += optind;
     95 	argc -= optind;
     96 
     97 	linkf = sflag ? symlink : link;
     98 
     99 	switch(argc) {
    100 	case 0:
    101 		usage();
    102 	case 1:				/* ln target */
    103 		exit(linkit(argv[0], ".", 1));
    104 	case 2:				/* ln target source */
    105 		exit(linkit(argv[0], argv[1], 0));
    106 	}
    107 					/* ln target1 target2 directory */
    108 	sourcedir = argv[argc - 1];
    109 	if (stat(sourcedir, &sb))
    110 		err(1, "%s", sourcedir);
    111 	if (!S_ISDIR(sb.st_mode))
    112 		usage();
    113 	for (exitval = 0; *argv != sourcedir; ++argv)
    114 		exitval |= linkit(*argv, sourcedir, 1);
    115 	exit(exitval);
    116 }
    117 
    118 int
    119 linkit(target, source, isdir)
    120 	char *target, *source;
    121 	int isdir;
    122 {
    123 	struct stat sb;
    124 	char *p, path[MAXPATHLEN];
    125 
    126 	if (!sflag) {
    127 		/* If target doesn't exist, quit now. */
    128 		if (stat(target, &sb)) {
    129 			warn("%s", target);
    130 			return (1);
    131 		}
    132 		/* Only symbolic links to directories, unless -F option used. */
    133 		if (!dirflag && S_ISDIR(sb.st_mode)) {
    134 			warnx("%s: is a directory", target);
    135 			return (1);
    136 		}
    137 	}
    138 
    139 	/* If the source is a directory, append the target's name. */
    140 	if (isdir || !stat(source, &sb) && S_ISDIR(sb.st_mode)) {
    141 		if ((p = strrchr(target, '/')) == NULL)
    142 			p = target;
    143 		else
    144 			++p;
    145 		(void)snprintf(path, sizeof(path), "%s/%s", source, p);
    146 		source = path;
    147 	}
    148 
    149 	/*
    150 	 * If the file exists, and -f was specified, unlink it.
    151 	 * Attempt the link.
    152 	 */
    153 	if (fflag && unlink(source) < 0 && errno != ENOENT ||
    154 	    (*linkf)(target, source)) {
    155 		warn("%s", source);
    156 		return (1);
    157 	}
    158 
    159 	return (0);
    160 }
    161 
    162 void
    163 usage()
    164 {
    165 
    166 	(void)fprintf(stderr,
    167 	    "usage:\tln [-fs] file1 file2\n\tln [-fs] file ... directory\n");
    168 	exit(1);
    169 }
    170