BSD 4_3_Tahoe release

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

/*
* Copyright (c) 1987 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#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        4.11 (Berkeley) 6/18/88";
#endif /* not lint */

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

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

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':
                       fflag = 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)) {
                       perror(sourcedir);
                       exit(1);
               }
               if ((buf.st_mode & S_IFMT) != S_IFDIR)
                       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;
{
       extern int      errno;
       struct stat     buf;
       char    path[MAXPATHLEN],
               *cp, *rindex(), *strcpy();

       if (!sflag) {
               /* if target doesn't exist, quit now */
               if (stat(target, &buf)) {
                       perror(target);
                       return(1);
               }
               /* only symbolic links to directories, unless -f option used */
               if (!fflag && (buf.st_mode & S_IFMT) == S_IFDIR) {
                       printf("%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)) {
               perror(source);
               return(1);
       }
       return(0);
}

static
usage()
{
       fputs("usage:\tln [-s] targetname [sourcename]\n\tln [-s] targetname1 targetname2 [... targetnameN] sourcedirectory\n", stderr);
       exit(1);
}