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ln.c revision 1.1 
      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[] = "@(#)ln.c	4.15 (Berkeley) 2/24/91";
     42 #endif /* not lint */
     43 
     44 #include <sys/param.h>
     45 #include <sys/stat.h>
     46 #include <stdio.h>
     47 #include <errno.h>
     48 #include <string.h>
     49 #include <stdlib.h>
     50 #include <unistd.h>
     51 
     52 static int	dirflag,			/* undocumented force flag */
     53 		sflag,				/* symbolic, not hard, link */
     54 		(*linkf)();			/* system link call */
     55 static linkit(), usage();
     56 
     57 main(argc, argv)
     58 	int argc;
     59 	char **argv;
     60 {
     61 	extern int optind;
     62 	struct stat buf;
     63 	int ch, exitval, link(), symlink();
     64 	char *sourcedir;
     65 
     66 	while ((ch = getopt(argc, argv, "Fs")) != EOF)
     67 		switch((char)ch) {
     68 		case 'F':
     69 			dirflag = 1;
     70 			break;
     71 		case 's':
     72 			sflag = 1;
     73 			break;
     74 		case '?':
     75 		default:
     76 			usage();
     77 		}
     78 
     79 	argv += optind;
     80 	argc -= optind;
     81 
     82 	linkf = sflag ? symlink : link;
     83 
     84 	switch(argc) {
     85 	case 0:
     86 		usage();
     87 	case 1:				/* ln target */
     88 		exit(linkit(argv[0], ".", 1));
     89 	case 2:				/* ln target source */
     90 		exit(linkit(argv[0], argv[1], 0));
     91 	default:			/* ln target1 target2 directory */
     92 		sourcedir = argv[argc - 1];
     93 		if (stat(sourcedir, &buf)) {
     94 			(void)fprintf(stderr,
     95 			    "ln: %s: %s\n", sourcedir, strerror(errno));
     96 			exit(1);
     97 		}
     98 		if (!S_ISDIR(buf.st_mode))
     99 			usage();
    100 		for (exitval = 0; *argv != sourcedir; ++argv)
    101 			exitval |= linkit(*argv, sourcedir, 1);
    102 		exit(exitval);
    103 	}
    104 	/* NOTREACHED */
    105 }
    106 
    107 static
    108 linkit(target, source, isdir)
    109 	char *target, *source;
    110 	int isdir;
    111 {
    112 	struct stat buf;
    113 	char path[MAXPATHLEN], *cp;
    114 
    115 	if (!sflag) {
    116 		/* if target doesn't exist, quit now */
    117 		if (stat(target, &buf)) {
    118 			(void)fprintf(stderr,
    119 			    "ln: %s: %s\n", target, strerror(errno));
    120 			return(1);
    121 		}
    122 		/* only symbolic links to directories, unless -F option used */
    123 		if (!dirflag && (buf.st_mode & S_IFMT) == S_IFDIR) {
    124 			(void)printf("ln: %s is a directory.\n", target);
    125 			return(1);
    126 		}
    127 	}
    128 
    129 	/* if the source is a directory, append the target's name */
    130 	if (isdir || !stat(source, &buf) && (buf.st_mode & S_IFMT) == S_IFDIR) {
    131 		if (!(cp = rindex(target, '/')))
    132 			cp = target;
    133 		else
    134 			++cp;
    135 		(void)sprintf(path, "%s/%s", source, cp);
    136 		source = path;
    137 	}
    138 
    139 	if ((*linkf)(target, source)) {
    140 		(void)fprintf(stderr, "ln: %s: %s\n", source, strerror(errno));
    141 		return(1);
    142 	}
    143 	return(0);
    144 }
    145 
    146 static
    147 usage()
    148 {
    149 	(void)fprintf(stderr,
    150 	    "usage:\tln [-s] file1 file2\n\tln [-s] file ... directory\n");
    151 	exit(1);
    152 }
    153