1 /* Reentrant versions of lseek system call. */
2 
3 #include <reent.h>
4 #include <unistd.h>
5 #include <_syslist.h>
6 
7 /* Some targets provides their own versions of this functions.  Those
8    targets should define REENTRANT_SYSCALLS_PROVIDED in TARGET_CFLAGS.  */
9 
10 #ifdef _REENT_ONLY
11 #ifndef REENTRANT_SYSCALLS_PROVIDED
12 #define REENTRANT_SYSCALLS_PROVIDED
13 #endif
14 #endif
15 
16 #ifndef REENTRANT_SYSCALLS_PROVIDED
17 
18 /* We use the errno variable used by the system dependent layer.  */
19 #undef errno
20 extern int errno;
21 
22 /*
23 FUNCTION
24 	<<_lseek_r>>---Reentrant version of lseek
25 
26 INDEX
27 	_lseek_r
28 
29 ANSI_SYNOPSIS
30 	#include <reent.h>
31 	off_t _lseek_r(struct _reent *<[ptr]>,
32 		       int <[fd]>, off_t <[pos]>, int <[whence]>);
33 
34 TRAD_SYNOPSIS
35 	#include <reent.h>
36 	off_t _lseek_r(<[ptr]>, <[fd]>, <[pos]>, <[whence]>)
37 	struct _reent *<[ptr]>;
38 	int <[fd]>;
39 	off_t <[pos]>;
40 	int <[whence]>;
41 
42 DESCRIPTION
43 	This is a reentrant version of <<lseek>>.  It
44 	takes a pointer to the global data block, which holds
45 	<<errno>>.
46 */
47 
48 _off_t
49 _DEFUN (_lseek_r, (ptr, fd, pos, whence),
50      struct _reent *ptr _AND
51      int fd _AND
52      _off_t pos _AND
53      int whence)
54 {
55   _off_t ret;
56 
57   errno = 0;
58   if ((ret = _lseek (fd, pos, whence)) == (_off_t) -1 && errno != 0)
59     ptr->_errno = errno;
60   return ret;
61 }
62 
63 #endif /* ! defined (REENTRANT_SYSCALLS_PROVIDED) */
64