fseek-nolock-fseeki64-nolock.md

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_fseek_nolock, _fseeki64_nolock	Learn more about: _fseek_nolock, _fseeki64_nolock	4/2/2020	_fseek_nolock _fseeki64_nolock _o__fseek_nolock _o__fseeki64_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	_fseek_nolock _fseeki64_nolock fseek_nolock fseeki64_nolock	_fseek_nolock function fseeki64_nolock function file pointers [C++], moving fseek_nolock function _fseeki64_nolock function seek file pointers

_fseek_nolock, _fseeki64_nolock

Moves the file pointer to a specified location without locking.

Syntax

int _fseek_nolock(
   FILE *stream,
   long offset,
   int origin
);
int _fseeki64_nolock(
   FILE *stream,
   __int64 offset,
   int origin
);

Parameters

stream
Pointer to the FILE structure.

offset
Number of bytes from origin.

origin
Initial position.

Return value

Same as fseek and _fseeki64, respectively.

Remarks

These functions are the non-locking versions of fseek and _fseeki64, respectively. These functions are identical to fseek and _fseeki64, 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
_fseek_nolock, _fseeki64_nolock	<stdio.h>

For more compatibility information, see Compatibility.

See also

Stream I/O
ftell, _ftelli64
_lseek, _lseeki64
rewind