Source code of Windows XP (NT5)
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.
 
 
 
 
 
 

65 lines
2.2 KiB

/***
*isatty.c - check if file handle refers to a device
*
* Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* defines _isatty() - check if file handle refers to a device
*
*Revision History:
* 06-08-89 PHG Module created
* 03-12-90 GJF Made calling type _CALLTYPE1, added #include
* <cruntime.h> and fixed the copyright. Also, cleaned
* up the formatting a bit.
* 08-14-90 SBM Compiles cleanly with -W3, minor optimization
* 09-28-90 GJF New-style function declarator.
* 12-04-90 GJF Appended Win32 version onto the source with #ifdef-s.
* It's not worth it to try to merge the versions more
* closely.
* 12-06-90 SRW Changed to use _osfile and _osfhnd instead of _osfinfo
* 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
* 06-06-95 GJF Replaced _osfile[] with _osfile() (macro referencing
* field in ioinfo struct).
* 07-08-96 GJF Replaced defined(_WIN32) with !defined(_MAC). Also,
* detab-ed.
* 05-17-99 PML Remove all Macintosh support.
*
*******************************************************************************/
#include <cruntime.h>
#include <msdos.h>
#include <internal.h>
#include <io.h>
/***
*int _isatty(handle) - check if handle is a device
*
*Purpose:
* Checks if the given handle is associated with a character device
* (terminal, console, printer, serial port)
*
*Entry:
* int handle - handle of file to be tested
*
*Exit:
* returns non-0 if handle refers to character device,
* returns 0 otherwise
*
*Exceptions:
*
*******************************************************************************/
int __cdecl _isatty (
int fh
)
{
/* see if file handle is valid, otherwise return FALSE */
if ( (unsigned)fh >= (unsigned)_nhandle )
return 0;
/* check file handle database to see if device bit set */
return (int)(_osfile(fh) & FDEV);
}