mirror of https://github.com/tongzx/nt5src
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
110 lines
3.5 KiB
110 lines
3.5 KiB
/***
|
|
*flength.c - find length of a file
|
|
*
|
|
* Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
|
|
*
|
|
*Purpose:
|
|
* defines _filelength() - find the length of a file
|
|
*
|
|
*Revision History:
|
|
* 10-22-84 RN initial version
|
|
* 10-27-87 JCR Multi-thread support; also, cleaned up code to save
|
|
* an lseek() in some cases.
|
|
* 12-11-87 JCR Added "_LOAD_DS" to declaration
|
|
* 05-25-88 PHG Merged DLL and normal versions
|
|
* 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.
|
|
* 07-23-90 SBM Removed #include <assertm.h>
|
|
* 09-28-90 GJF New-style function declarator.
|
|
* 12-04-90 GJF Improved range check of file handle. Also, replaced
|
|
* numeric values with symbolic constants for seek
|
|
* methods.
|
|
* 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 REG1 macro. Also,
|
|
* detab-ed and cleaned up the format a bit.
|
|
* 12-19-97 GJF Exception-safe locking.
|
|
* 05-17-99 PML Remove all Macintosh support.
|
|
*
|
|
*******************************************************************************/
|
|
|
|
#include <cruntime.h>
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
#include <io.h>
|
|
#include <internal.h>
|
|
#include <msdos.h>
|
|
#include <mtdll.h>
|
|
#include <stddef.h>
|
|
#include <stdlib.h>
|
|
|
|
/***
|
|
*long _filelength(filedes) - find length of a file
|
|
*
|
|
*Purpose:
|
|
* Returns the length in bytes of the specified file.
|
|
*
|
|
*Entry:
|
|
* int filedes - handle referring to file to find length of
|
|
*
|
|
*Exit:
|
|
* returns length of file in bytes
|
|
* returns -1L if fails
|
|
*
|
|
*Exceptions:
|
|
*
|
|
*******************************************************************************/
|
|
|
|
long __cdecl _filelength (
|
|
int filedes
|
|
)
|
|
{
|
|
long length;
|
|
long here;
|
|
|
|
if ( ((unsigned)filedes >= (unsigned)_nhandle) ||
|
|
!(_osfile(filedes) & FOPEN) )
|
|
{
|
|
errno = EBADF;
|
|
_doserrno = 0L; /* not an OS error */
|
|
return(-1L);
|
|
}
|
|
|
|
#ifdef _MT
|
|
_lock_fh(filedes);
|
|
__try {
|
|
if ( _osfile(filedes) & FOPEN ) {
|
|
#endif /* _MT */
|
|
|
|
/* Seek to end to get length of file. */
|
|
if ( (here = _lseek_lk(filedes, 0L, SEEK_CUR)) == -1L )
|
|
length = -1L; /* return error */
|
|
else {
|
|
length = _lseek_lk(filedes, 0L, SEEK_END);
|
|
if ( here != length )
|
|
_lseek_lk(filedes, here, SEEK_SET);
|
|
}
|
|
|
|
#ifdef _MT
|
|
}
|
|
else {
|
|
errno = EBADF;
|
|
_doserrno = 0L;
|
|
length = -1L;
|
|
}
|
|
}
|
|
__finally {
|
|
_unlock_fh(filedes);
|
|
}
|
|
#endif /* _MT */
|
|
|
|
return(length);
|
|
}
|