xref: /openbsd-src/gnu/usr.bin/cvs/lib/rename.c (revision 1e72d8d26fae84dfb4bcd4cecabd10b989ec3f29)
1 /* rename.c -- BSD compatible directory function for System V
2    Copyright (C) 1988, 1990 Free Software Foundation, Inc.
3 
4    This program is free software; you can redistribute it and/or modify
5    it under the terms of the GNU General Public License as published by
6    the Free Software Foundation; either version 2, or (at your option)
7    any later version.
8 
9    This program is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12    GNU General Public License for more details.
13 
14    You should have received a copy of the GNU General Public License
15    along with this program; if not, write to the Free Software
16    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
17 
18 #ifdef HAVE_CONFIG_H
19 #include "config.h"
20 #endif
21 
22 #include <sys/types.h>
23 #include <sys/stat.h>
24 #include <errno.h>
25 #ifndef STDC_HEADERS
26 extern int errno;
27 #endif
28 
29 /* Rename file FROM to file TO.
30    Return 0 if successful, -1 if not. */
31 
32 int
33 rename (from, to)
34      char *from;
35      char *to;
36 {
37   struct stat from_stats;
38   int pid, status;
39 
40   if (stat (from, &from_stats) == 0)
41     {
42       if (unlink (to) && errno != ENOENT)
43 	return -1;
44       if ((from_stats.st_mode & S_IFMT) == S_IFDIR)
45 	{
46 #ifdef MVDIR
47 	  /* I don't think MVDIR ever gets defined, but I don't think
48 	     it matters, because I don't think CVS ever calls rename()
49 	     on directories.  */
50 
51 	  /* Need a setuid root process to link and unlink directories. */
52 	  pid = fork ();
53 	  switch (pid)
54 	    {
55 	    case -1:		/* Error. */
56 	      error (1, errno, "cannot fork");
57 
58 	    case 0:		/* Child. */
59 	      execl (MVDIR, "mvdir", from, to, (char *) 0);
60 	      error (255, errno, "cannot run `%s'", MVDIR);
61 
62 	    default:		/* Parent. */
63 	      while (wait (&status) != pid)
64 		/* Do nothing. */ ;
65 
66 	      errno = 0;	/* mvdir printed the system error message. */
67 	      return status != 0 ? -1 : 0;
68 	    }
69 #else /* no MVDIR */
70 	  error (1, 0, "internal error: cannot move directories");
71 #endif /* no MVDIR */
72 	}
73       else
74 	{
75 	  if (link (from, to) == 0 && (unlink (from) == 0 || errno == ENOENT))
76 	    return 0;
77 	}
78     }
79   return -1;
80 }
81