fgetc-nolock-fgetwc-nolock.md

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Learn more about: _fgetc_nolock, _fgetwc_nolock	_fgetc_nolock, _fgetwc_nolock	4/2/2020	_fgetc_nolock _fgetwc_nolock _o__fgetc_nolock _o__fgetwc_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	_fgetwc_nolock fgettc_nolock fgetwc_nolock _fgetc_nolock _fgettc_nolock fgetc_nolock	fgetc_nolock function fgetwc_nolock function _fgetwc_nolock function characters, reading _fgetc_nolock function streams, reading characters from fgettc_nolock function reading characters from streams _fgettc_nolock function	fb8e7c5b-4503-493a-879e-6a1db75aa114

_fgetc_nolock, _fgetwc_nolock

Reads a character from a stream without locking the thread.

Syntax

int _fgetc_nolock(
   FILE *stream
);
wint_t _fgetwc_nolock(
   FILE *stream
);

Parameters

stream
Pointer to the FILE structure.

Return value

Seefgetc, fgetwc.

Remarks

_fgetc_nolock and _fgetwc_nolock are identical to fgetc and fgetwc, respectively, except that they aren't protected from interference by other threads. They 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.

Generic-text routine mappings

Tchar.h routine	_UNICODE and _MBCS not defined	_MBCS defined	_UNICODE defined
_fgettc_nolock	_fgetc_nolock	_fgetc_nolock	_fgetwc_nolock

Requirements

Function	Required header
_fgetc_nolock	<stdio.h>
_fgetwc_nolock	<stdio.h> or <wchar.h>

For more compatibility information, see Compatibility.

Example

// crt_fgetc_nolock.c
// This program uses getc to read the first
// 80 input characters (or until the end of input)
// and place them into a string named buffer.

#include <stdio.h>
#include <stdlib.h>

int main( void )
{
   FILE *stream;
   char buffer[81];
   int  i, ch;

   // Open file to read line from:
   if( fopen_s( &stream, "crt_fgetc_nolock.txt", "r" ) != 0 )
      exit( 0 );

   // Read in first 80 characters and place them in "buffer":
   ch = fgetc( stream );
   for( i=0; (i < 80 ) && ( feof( stream ) == 0 ); i++ )
   {
      buffer[i] = (char)ch;
      ch = _fgetc_nolock( stream );
   }

   // Add null to end string
   buffer[i] = '\0';
   printf( "%s\n", buffer );
   fclose( stream );
}

Input: crt_fgetc_nolock.txt

Line one.
Line two.

Output

Line one.
Line two.

See also

Stream I/O
fputc, fputwc
getc, getwc