Source code of Windows XP (NT5)
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/***
*eof.c - test a handle for end of file
*
* Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* defines _eof() - determine if a file is at eof
*
*Revision History:
* 09-07-83 RN initial version
* 10-28-87 JCR Multi-thread support
* 12-11-87 JCR Added "_LOAD_DS" to declaration
* 05-25-88 PHG DLL replaces normal version
* 07-11-88 JCR Added REG allocation to declarations
* 03-12-90 GJF Replaced _LOAD_DS with _CALLTYPE1, added #include
* <cruntime.h>, removed #include <register.h> and fixed
* the copyright. Also, cleaned up the formatting a bit.
* 09-28-90 GJF New-style function declarator.
* 12-04-90 GJF Improved range check of file handle.
* 01-16-91 GJF ANSI naming.
* 02-13-92 GJF Replaced _nfile by _nhandle for Win32.
* 04-06-93 SKS Replace _CRTAPI* with __cdecl
* 01-04-95 GJF _WIN32_ -> _WIN32
* 02-15-95 GJF Appended Mac version of source file (somewhat cleaned
* up), with appropriate #ifdef-s.
* 06-27-95 GJF Added check that the file handle is open.
* 07-08-96 GJF Replaced defined(_WIN32) with !defined(_MAC), and
* defined(_M_M68K) || defined(_M_MPPC) with
* defined(_MAC). Removed obsolete REG* macros. Also,
* detab-ed and cleaned up the format a bit.
* 12-17-97 GJF Exception-safe locking.
* 09-23-98 GJF Use _lseeki64_lk so _eof works on BIG files
* 05-17-99 PML Remove all Macintosh support.
*
*******************************************************************************/
#include <cruntime.h>
#include <io.h>
#include <errno.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <internal.h>
#include <msdos.h>
#include <mtdll.h>
/***
*int _eof(filedes) - test a file for eof
*
*Purpose:
* see if the file length is the same as the present position. if so, return
* 1. if not, return 0. if an error occurs, return -1
*
*Entry:
* int filedes - handle of file to test
*
*Exit:
* returns 1 if at eof
* returns 0 if not at eof
* returns -1 and sets errno if fails
*
*Exceptions:
*
*******************************************************************************/
int __cdecl _eof (
int filedes
)
{
__int64 here;
__int64 end;
int retval;
if ( ((unsigned)filedes >= (unsigned)_nhandle) ||
!(_osfile(filedes) & FOPEN) )
{
errno = EBADF;
_doserrno = 0;
return(-1);
}
#ifdef _MT
/* Lock the file */
_lock_fh(filedes);
__try {
if ( _osfile(filedes) & FOPEN ) {
#endif /* _MT */
/* See if the current position equals the end of the file. */
if ( ((here = _lseeki64_lk(filedes, 0i64, SEEK_CUR)) == -1i64) ||
((end = _lseeki64_lk(filedes, 0i64, SEEK_END)) == -1i64) )
retval = -1;
else if ( here == end )
retval = 1;
else {
_lseeki64_lk(filedes, here, SEEK_SET);
retval = 0;
}
#ifdef _MT
}
else {
errno = EBADF;
_doserrno = 0;
retval = -1;
}
}
__finally {
/* Unlock the file */
_unlock_fh(filedes);
}
#endif /* _MT */
/* Done */
return(retval);
}