2020-09-30 17:12:29 +02:00

91 lines
2.1 KiB
C

/***
*eof.c - test a handle for end of file
*
* Copyright (c) 1985-1992, 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.
*
*******************************************************************************/
#include <cruntime.h>
#include <io.h>
#include <errno.h>
#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <internal.h>
#include <os2dll.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 _CALLTYPE1 _eof (
REG1 int filedes
)
{
long here;
long end;
REG2 int retval;
#ifdef _WIN32_
if ( (unsigned)filedes >= (unsigned)_nhandle ) {
#else
if ( (unsigned)filedes >= (unsigned)_nfile ) {
#endif
errno = EBADF;
_doserrno = 0;
return(-1);
}
/* Lock the file */
_lock_fh(filedes);
/* See if the current position equals the end of the file. */
if ( ((here = _lseek_lk(filedes, 0L, SEEK_CUR)) == -1L)
|| ((end = _lseek_lk(filedes, 0L, SEEK_END)) == -1L) )
retval = -1;
else if ( here == end )
retval = 1;
else {
_lseek_lk(filedes, here, SEEK_SET);
retval = 0;
}
/* Unlock the file */
_unlock_fh(filedes);
/* Done */
return(retval);
}