newlib/libc/reent/lseek64r.c

   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 __LARGE64_FILES
  11
  12 #ifdef _REENT_ONLY
  13 #ifndef REENTRANT_SYSCALLS_PROVIDED
  14 #define REENTRANT_SYSCALLS_PROVIDED
  15 #endif
  16 #endif
  17
  18 #ifndef REENTRANT_SYSCALLS_PROVIDED
  19
  20 /* We use the errno variable used by the system dependent layer.  */
  21 #undef errno
  22 extern int errno;
  23
  24 /*
  25 FUNCTION
  26         <<_lseek64_r>>---Reentrant version of lseek
  27
  28 INDEX
  29         _lseek64_r
  30
  31 SYNOPSIS
  32         #include <reent.h>
  33         off64_t _lseek64_r(struct _reent *<[ptr]>,
  34                            int <[fd]>, off64_t <[pos]>, int <[whence]>);
  35
  36 DESCRIPTION
  37         This is a reentrant version of <<lseek64>>.  It
  38         takes a pointer to the global data block, which holds
  39         <<errno>>.  This function only exists on a system
  40         with large file support.
  41 */
  42
  43 _off64_t
  44 _lseek64_r (struct _reent *ptr,
  45      int fd,
  46      _off64_t pos,
  47      int whence)
  48 {
  49   _off64_t ret;
  50
  51   errno = 0;
  52   if ((ret = _lseek64 (fd, pos, whence)) == (_off64_t) -1 && errno != 0)
  53     _REENT_ERRNO(ptr) = errno;
  54   return ret;
  55 }
  56
  57 #endif /* ! defined (REENTRANT_SYSCALLS_PROVIDED) */
  58
  59 #endif /* __LARGE64_FILES */