BSD 4_3_Net_2 release

[unix-history] / usr / src / bin / ln / ln.c

/*
* Copyright (c) 1987 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
*    must display the following acknowledgement:
*      This product includes software developed by the University of
*      California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1987 Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)ln.c        4.15 (Berkeley) 2/24/91";
#endif /* not lint */

#include <sys/param.h>
#include <sys/stat.h>
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>

static int      dirflag,                        /* undocumented force flag */
               sflag,                          /* symbolic, not hard, link */
               (*linkf)();                     /* system link call */
static linkit(), usage();

main(argc, argv)
       int argc;
       char **argv;
{
       extern int optind;
       struct stat buf;
       int ch, exitval, link(), symlink();
       char *sourcedir;

       while ((ch = getopt(argc, argv, "Fs")) != EOF)
               switch((char)ch) {
               case 'F':
                       dirflag = 1;
                       break;
               case 's':
                       sflag = 1;
                       break;
               case '?':
               default:
                       usage();
               }

       argv += optind;
       argc -= optind;

       linkf = sflag ? symlink : link;

       switch(argc) {
       case 0:
               usage();
       case 1:                         /* ln target */
               exit(linkit(argv[0], ".", 1));
       case 2:                         /* ln target source */
               exit(linkit(argv[0], argv[1], 0));
       default:                        /* ln target1 target2 directory */
               sourcedir = argv[argc - 1];
               if (stat(sourcedir, &buf)) {
                       (void)fprintf(stderr,
                           "ln: %s: %s\n", sourcedir, strerror(errno));
                       exit(1);
               }
               if (!S_ISDIR(buf.st_mode))
                       usage();
               for (exitval = 0; *argv != sourcedir; ++argv)
                       exitval |= linkit(*argv, sourcedir, 1);
               exit(exitval);
       }
       /* NOTREACHED */
}

static
linkit(target, source, isdir)
       char *target, *source;
       int isdir;
{
       struct stat buf;
       char path[MAXPATHLEN], *cp;

       if (!sflag) {
               /* if target doesn't exist, quit now */
               if (stat(target, &buf)) {
                       (void)fprintf(stderr,
                           "ln: %s: %s\n", target, strerror(errno));
                       return(1);
               }
               /* only symbolic links to directories, unless -F option used */
               if (!dirflag && (buf.st_mode & S_IFMT) == S_IFDIR) {
                       (void)printf("ln: %s is a directory.\n", target);
                       return(1);
               }
       }

       /* if the source is a directory, append the target's name */
       if (isdir || !stat(source, &buf) && (buf.st_mode & S_IFMT) == S_IFDIR) {
               if (!(cp = rindex(target, '/')))
                       cp = target;
               else
                       ++cp;
               (void)sprintf(path, "%s/%s", source, cp);
               source = path;
       }

       if ((*linkf)(target, source)) {
               (void)fprintf(stderr, "ln: %s: %s\n", source, strerror(errno));
               return(1);
       }
       return(0);
}

static
usage()
{
       (void)fprintf(stderr,
           "usage:\tln [-s] file1 file2\n\tln [-s] file ... directory\n");
       exit(1);
}