1 /* Copyright (C) 2005 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
9 The GNU C Library 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 GNU
12 Lesser General Public License for more details.
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, write to the Free
16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
27 /* Make a link to FROM named TO but relative paths in TO and FROM are
28 interpreted relative to FROMFD and TOFD respectively. */
30 linkat (fromfd
, from
, tofd
, to
)
36 static const char procfd
[] = "/proc/self/fd/%d/%s";
39 if (fromfd
!= AT_FDCWD
&& from
[0] != '/')
41 size_t filelen
= strlen (from
);
42 /* Buffer for the path name we are going to use. It consists of
43 - the string /proc/self/fd/
44 - the file descriptor number
45 - the file name provided.
46 The final NUL is included in the sizeof. A bit of overhead
47 due to the format elements compensates for possible negative
49 size_t buflen
= sizeof (procfd
) + sizeof (int) * 3 + filelen
;
50 buffrom
= alloca (buflen
);
52 __snprintf (buffrom
, buflen
, procfd
, fromfd
, from
);
58 if (tofd
!= AT_FDCWD
&& to
[0] != '/')
60 size_t filelen
= strlen (to
);
61 /* Buffer for the path name we are going to use. It consists of
62 - the string /proc/self/fd/
63 - the file descriptor number
64 - the file name provided.
65 The final NUL is included in the sizeof. A bit of overhead
66 due to the format elements compensates for possible negative
68 size_t buflen
= sizeof (procfd
) + sizeof (int) * 3 + filelen
;
69 bufto
= alloca (buflen
);
71 __snprintf (bufto
, buflen
, procfd
, tofd
, to
);
75 INTERNAL_SYSCALL_DECL (err
);
77 int result
= INTERNAL_SYSCALL (link
, err
, 2, from
, to
);
79 if (__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result
, err
), 0))
81 __atfct_seterrno_2 (INTERNAL_SYSCALL_ERRNO (result
, err
), tofd
, bufto
,