kolibrios/programs/develop/libraries/newlib/reent/lseekr.c
Sergey Semyonov (Serge) 0a3f4b2193 Newlib source code
git-svn-id: svn://kolibrios.org@1693 a494cfbc-eb01-0410-851d-a64ba20cac60
2010-11-07 13:42:29 +00:00

160 lines
2.9 KiB
C

/* Reentrant versions of lseek system call. */
#include <reent.h>
#include <unistd.h>
#include <_syslist.h>
#include <errno.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
#pragma pack(push, 1)
typedef struct
{
char sec;
char min;
char hour;
char rsv;
}detime_t;
typedef struct
{
char day;
char month;
short year;
}dedate_t;
typedef struct
{
unsigned attr;
unsigned flags;
union
{
detime_t ctime;
unsigned cr_time;
};
union
{
dedate_t cdate;
unsigned cr_date;
};
union
{
detime_t atime;
unsigned acc_time;
};
union
{
dedate_t adate;
unsigned acc_date;
};
union
{
detime_t mtime;
unsigned mod_time;
};
union
{
dedate_t mdate;
unsigned mod_date;
};
unsigned size;
unsigned size_high;
} FILEINFO;
#pragma pack(pop)
extern unsigned __NFiles;
#define __handle_check( __h, __r ) \
if( (__h) < 0 || (__h) > __NFiles ) { \
ptr->_errno = EBADF ; \
return( __r ); \
}
/*
FUNCTION
<<_lseek_r>>---Reentrant version of lseek
INDEX
_lseek_r
ANSI_SYNOPSIS
#include <reent.h>
off_t _lseek_r(struct _reent *<[ptr]>,
int <[fd]>, off_t <[pos]>, int <[whence]>);
TRAD_SYNOPSIS
#include <reent.h>
off_t _lseek_r(<[ptr]>, <[fd]>, <[pos]>, <[whence]>)
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
_DEFUN (_lseek_r, (ptr, fd, pos, whence),
struct _reent *ptr _AND
int fd _AND
_off_t pos _AND
int whence)
{
_off_t ret;
__file_handle *fh;
__handle_check( fd, -1 );
fh = (__file_handle*) __getOSHandle( fd );
switch(whence)
{
case SEEK_SET:
ret = pos;
break;
case SEEK_CUR:
ret = fh->offset + pos;
break;
case SEEK_END:
{
FILEINFO info;
get_fileinfo(fh->name, &info);
ret = pos + info.size;
break;
}
default:
ptr->_errno = EINVAL;
return -1;
};
fh->offset = ret;
return( ret );
}
_off_t
_DEFUN (lseek, (fd, pos, whence),
int fd _AND
_off_t pos _AND
int whence)
{
return _lseek_r(_REENT, fd, pos, whence);
};
#endif /* ! defined (REENTRANT_SYSCALLS_PROVIDED) */