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ln.c revision 1.7 
      1 /*
      2  * Copyright (c) 1987 Regents of the University of California.
      3  * 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 
     34 #ifndef lint
     35 char copyright[] =
     36 "@(#) Copyright (c) 1987 Regents of the University of California.\n\
     37  All rights reserved.\n";
     38 #endif /* not lint */
     39 
     40 #ifndef lint
     41 /*static char sccsid[] = "from: @(#)ln.c	4.15 (Berkeley) 2/24/91";*/
     42 static char rcsid[] = "$Id: ln.c,v 1.7 1994/01/27 02:00:45 jtc Exp $";
     43 #endif /* not lint */
     44 
     45 #include <sys/param.h>
     46 #include <sys/stat.h>
     47 #include <stdio.h>
     48 #include <errno.h>
     49 #include <string.h>
     50 #include <stdlib.h>
     51 #include <unistd.h>
     52 #include <err.h>
     53 
     54 static int	forceflag,		/* force link by removing target */
     55 		dirflag,		/* allow hard links to directories */
     56 		sflag,			/* symbolic, not hard, link */
     57 		(*linkf)();		/* system link call */
     58 static int	linkit();
     59 static void	usage();
     60 
     61 int
     62 main(argc, argv)
     63 	int argc;
     64 	char **argv;
     65 {
     66 	extern int optind;
     67 	struct stat buf;
     68 	int ch, exitval;
     69 	char *sourcedir;
     70 
     71 	while ((ch = getopt(argc, argv, "fFs")) != EOF)
     72 		switch((char)ch) {
     73 		case 'f':
     74 			forceflag = 1;
     75 			break;
     76 		case 'F':
     77 			dirflag = 1;
     78 			break;
     79 		case 's':
     80 			sflag = 1;
     81 			break;
     82 		case '?':
     83 		default:
     84 			usage();
     85 		}
     86 
     87 	argv += optind;
     88 	argc -= optind;
     89 
     90 	linkf = sflag ? symlink : link;
     91 
     92 	switch(argc) {
     93 	case 0:
     94 		usage();
     95 		/* NOTREACHED */
     96 	case 1:				/* ln target */
     97 		exit(linkit(argv[0], ".", 1));
     98 		/* NOTREACHED */
     99 	case 2:				/* ln target source */
    100 		exit(linkit(argv[0], argv[1], 0));
    101 		/* NOTREACHED */
    102 	default:			/* ln target1 target2 directory */
    103 		sourcedir = argv[argc - 1];
    104 		if (stat(sourcedir, &buf)) {
    105 			err(1, "%s", sourcedir);
    106 			/* NOTREACHED */
    107 		}
    108 		if (!S_ISDIR(buf.st_mode))
    109 			usage();
    110 		for (exitval = 0; *argv != sourcedir; ++argv)
    111 			exitval |= linkit(*argv, sourcedir, 1);
    112 		exit(exitval);
    113 	}
    114 	/* NOTREACHED */
    115 }
    116 
    117 static int
    118 linkit(source, target, isdir)
    119 	char *source, *target;
    120 	int isdir;
    121 {
    122 	struct stat buf;
    123 	char path[MAXPATHLEN], *cp;
    124 
    125 	if (!sflag) {
    126 		/* if source doesn't exist, quit now */
    127 		if (stat(source, &buf)) {
    128 			warn("%s", source);
    129 			return(1);
    130 		}
    131 		/* only symbolic links to directories, unless -F option used */
    132 		if (!dirflag && (buf.st_mode & S_IFMT) == S_IFDIR) {
    133 			warnx("%s: %s", source, EISDIR);
    134 			return(1);
    135 		}
    136 	}
    137 
    138 	/* if the target is a directory, append the source's name */
    139 	if (isdir || !stat(target, &buf) && S_ISDIR(buf.st_mode)) {
    140 		if (!(cp = rindex(source, '/')))
    141 			cp = source;
    142 		else
    143 			++cp;
    144 		(void)sprintf(path, "%s/%s", target, cp);
    145 		target = path;
    146 	}
    147 
    148 	/* Remove existing file if -f is was specified */
    149 	if (forceflag && unlink (target) && errno != ENOENT) {
    150 		warn("%s", target);
    151 		return (1);
    152 	}
    153 
    154 	if ((*linkf)(source, target)) {
    155 		warn("%s", target);
    156 		return(1);
    157 	}
    158 
    159 	return(0);
    160 }
    161 
    162 static void
    163 usage()
    164 {
    165 	(void)fprintf(stderr,
    166 	    "usage:\tln [-fs] file1 file2\n\tln [-fs] file ... directory\n");
    167 	exit(1);
    168 }
    169