newlib-cygwin/newlib/libc/reent/lseekr.c

55 lines
1.1 KiB
C

/* Reentrant versions of lseek system call. */
#include <reent.h>
#include <unistd.h>
#include <_syslist.h>
/* Some targets provides their own versions of this functions. Those
targets should define REENTRANT_SYSCALLS_PROVIDED in TARGET_CFLAGS. */
#ifdef _REENT_ONLY
#ifndef REENTRANT_SYSCALLS_PROVIDED
#define REENTRANT_SYSCALLS_PROVIDED
#endif
#endif
#ifndef REENTRANT_SYSCALLS_PROVIDED
/* We use the errno variable used by the system dependent layer. */
#undef errno
extern int errno;
/*
FUNCTION
<<_lseek_r>>---Reentrant version of lseek
INDEX
_lseek_r
SYNOPSIS
#include <reent.h>
off_t _lseek_r(struct _reent *<[ptr]>,
int <[fd]>, off_t <[pos]>, int <[whence]>);
DESCRIPTION
This is a reentrant version of <<lseek>>. It
takes a pointer to the global data block, which holds
<<errno>>.
*/
_off_t
_lseek_r (struct _reent *ptr,
int fd,
_off_t pos,
int whence)
{
_off_t ret;
errno = 0;
if ((ret = _lseek (fd, pos, whence)) == (_off_t) -1 && errno != 0)
_REENT_ERRNO(ptr) = errno;
return ret;
}
#endif /* ! defined (REENTRANT_SYSCALLS_PROVIDED) */