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/***
*flength.c - find length of a file
*
* Copyright (c) 1985-1992, 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.
*
*******************************************************************************/
#include <cruntime.h>
#include <stdio.h>
#include <errno.h>
#include <io.h>
#include <internal.h>
#include <os2dll.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 _CALLTYPE1 _filelength (
REG1 int filedes
)
{
long length;
long here;
#ifdef _WIN32_
if ( (unsigned)filedes >= (unsigned)_nhandle ) {
#else
if ( (unsigned)filedes >= (unsigned)_nfile ) {
#endif
errno = EBADF;
_doserrno = 0L; /* not an OS error */
return(-1L);
}
_lock_fh(filedes);
/* 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);
}
_unlock_fh(filedes);
return(length);
}
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