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ln.c revision 1.4 
      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 1.4 1993/08/01 18:59:33 mycroft 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 
     53 static int	dirflag,			/* undocumented force flag */
     54 		sflag,				/* symbolic, not hard, link */
     55 		(*linkf)();			/* system link call */
     56 static linkit(), usage();
     57 
     58 main(argc, argv)
     59 	int argc;
     60 	char **argv;
     61 {
     62 	extern int optind;
     63 	struct stat buf;
     64 	int ch, exitval, link(), symlink();
     65 	char *sourcedir;
     66 
     67 	while ((ch = getopt(argc, argv, "Fs")) != EOF)
     68 		switch((char)ch) {
     69 		case 'F':
     70 			dirflag = 1;
     71 			break;
     72 		case 's':
     73 			sflag = 1;
     74 			break;
     75 		case '?':
     76 		default:
     77 			usage();
     78 		}
     79 
     80 	argv += optind;
     81 	argc -= optind;
     82 
     83 	linkf = sflag ? symlink : link;
     84 
     85 	switch(argc) {
     86 	case 0:
     87 		usage();
     88 	case 1:				/* ln target */
     89 		exit(linkit(argv[0], ".", 1));
     90 	case 2:				/* ln target source */
     91 		exit(linkit(argv[0], argv[1], 0));
     92 	default:			/* ln target1 target2 directory */
     93 		sourcedir = argv[argc - 1];
     94 		if (stat(sourcedir, &buf)) {
     95 			(void)fprintf(stderr,
     96 			    "ln: %s: %s\n", sourcedir, strerror(errno));
     97 			exit(1);
     98 		}
     99 		if (!S_ISDIR(buf.st_mode))
    100 			usage();
    101 		for (exitval = 0; *argv != sourcedir; ++argv)
    102 			exitval |= linkit(*argv, sourcedir, 1);
    103 		exit(exitval);
    104 	}
    105 	/* NOTREACHED */
    106 }
    107 
    108 static
    109 linkit(target, source, isdir)
    110 	char *target, *source;
    111 	int isdir;
    112 {
    113 	struct stat buf;
    114 	char path[MAXPATHLEN], *cp;
    115 
    116 	if (!sflag) {
    117 		/* if target doesn't exist, quit now */
    118 		if (stat(target, &buf)) {
    119 			(void)fprintf(stderr,
    120 			    "ln: %s: %s\n", target, strerror(errno));
    121 			return(1);
    122 		}
    123 		/* only symbolic links to directories, unless -F option used */
    124 		if (!dirflag && (buf.st_mode & S_IFMT) == S_IFDIR) {
    125 			(void)printf("ln: %s is a directory.\n", target);
    126 			return(1);
    127 		}
    128 	}
    129 
    130 	/* if the source is a directory, append the target's name */
    131 	if (isdir || !stat(source, &buf) && (buf.st_mode & S_IFMT) == S_IFDIR) {
    132 		if (!(cp = rindex(target, '/')))
    133 			cp = target;
    134 		else
    135 			++cp;
    136 		(void)sprintf(path, "%s/%s", source, cp);
    137 		source = path;
    138 	}
    139 
    140 	if ((*linkf)(target, source)) {
    141 		(void)fprintf(stderr, "ln: %s: %s\n", source, strerror(errno));
    142 		return(1);
    143 	}
    144 	return(0);
    145 }
    146 
    147 static
    148 usage()
    149 {
    150 	(void)fprintf(stderr,
    151 	    "usage:\tln [-s] file1 file2\n\tln [-s] file ... directory\n");
    152 	exit(1);
    153 }
    154