ftell-nolock-ftelli64-nolock.md

title	description	ms.date	api_name	api_location	api_type	topic_type	f1_keywords	helpviewer_keywords
_ftell_nolock, _ftelli64_nolock	Learn more about: _ftell_nolock, _ftelli64_nolock	4/2/2020	_ftelli64_nolock _ftell_nolock _o__ftell_nolock _o__ftelli64_nolock	msvcrt.dll msvcr80.dll msvcr90.dll msvcr100.dll msvcr100_clr0400.dll msvcr110.dll msvcr110_clr0400.dll msvcr120.dll msvcr120_clr0400.dll ucrtbase.dll api-ms-win-crt-stdio-l1-1-0.dll	DLLExport	apiref	_ftelli64_nolock ftelli64_nolock ftell_nolock _ftell_nolock	ftelli64_nolock function _ftelli64_nolock function _ftell_nolock function ftell_nolock function file pointers [C++], getting current position

_ftell_nolock, _ftelli64_nolock

Gets the current position of a file pointer without locking.

Syntax

long _ftell_nolock(
   FILE *stream
);
__int64 _ftelli64_nolock(
   FILE *stream
);

Parameters

stream
Target the FILE structure.

Return value

Same as ftell and _ftelli64. For more information, see ftell, _ftelli64.

Remarks

These functions are non-locking versions of ftell and _ftelli64, respectively. They're identical to ftell and _ftelli64 except that they aren't protected from interference by other threads. These functions might be faster because they don't incur the overhead of locking out other threads. Use these functions only in thread-safe contexts such as single-threaded applications or where the calling scope already handles thread isolation.

By default, this function's global state is scoped to the application. To change this behavior, see Global state in the CRT.

Requirements

Function	Required header	Optional header
ftell_nolock	<stdio.h>	<errno.h>
_ftelli64_nolock	<stdio.h>	<errno.h>

For more compatibility information, see Compatibility.

See also

Stream I/O
fgetpos
fseek, _fseeki64
_lseek, _lseeki64
ftell, _ftelli64