4.4BSD snapshot (revision 8.1); add 1993 to copyright

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

/*
* Copyright (c) 1987 Regents of the University of California.
* All rights reserved.
*
* %sccs.include.redist.c%
*/

#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        5.1 (Berkeley) %G%";
#endif /* not lint */

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

#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int     dirflag,                        /* Undocumented force flag. */
       sflag,                          /* Symbolic, not hard, link. */
                                       /* System link call. */
       (*linkf) __P((const char *, const char *));

static int      linkit __P((char *, char *, int));
static void     usage __P((void));

int
main(argc, argv)
       int argc;
       char *argv[];
{
       extern int optind;
       struct stat sb;
       int ch, exitval;
       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));
       }
                                       /* ln target1 target2 directory */
       sourcedir = argv[argc - 1];
       if (stat(sourcedir, &sb))
               err(1, "%s", sourcedir);
       if (!S_ISDIR(sb.st_mode))
               usage();
       for (exitval = 0; *argv != sourcedir; ++argv)
               exitval |= linkit(*argv, sourcedir, 1);
       exit(exitval);
}

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

       if (!sflag) {
               /* if target doesn't exist, quit now */
               if (stat(target, &sb)) {
                       warn("%s", target);
                       return (1);
               }
               /* only symbolic links to directories, unless -F option used */
               if (!dirflag && (sb.st_mode & S_IFMT) == S_IFDIR) {
                       warnx("%s: is a directory", target);
                       return (1);
               }
       }

       /* if the source is a directory, append the target's name */
       if (isdir || !stat(source, &sb) && (sb.st_mode & S_IFMT) == S_IFDIR) {
               if (!(p = strrchr(target, '/')))
                       p = target;
               else
                       ++p;
               (void)snprintf(path, sizeof(path), "%s/%s", source, p);
               source = path;
       }

       if ((*linkf)(target, source)) {
               warn("%s", source);
               return (1);
       }
       return (0);
}

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