getc-nolock-getwc-nolock.md

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_getc_nolock, _getwc_nolock	Learn more about: _getc_nolock, _getwc_nolock	4/2/2020	_getc_nolock _getwc_nolock _o__getc_nolock _o__getwc_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	getc_nolock _gettc_nolock _getc_nolock getwc_nolock gettc_nolock _getwc_nolock	characters, reading _getc_nolock function _getwc_nolock function getwc_nolock function streams, reading characters from reading characters from streams getc_nolock function gettc_nolock function _gettc_nolock function

_getc_nolock, _getwc_nolock

Reads a character from a stream without locking.

Syntax

int _getc_nolock(
   FILE *stream
);
wint_t _getwc_nolock(
   FILE *stream
);

Parameters

stream
Input stream.

Return value

See getc, getwc.

Remarks

These functions are identical to getc and getwc except that they don't lock the calling thread. 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
_gettc_nolock	getc_nolock	getc_nolock	getwc_nolock

Requirements

Routine	Required header
getc_nolock	<stdio.h>
getwc_nolock	<stdio.h> or <wchar.h>

For more compatibility information, see Compatibility.

Example

// crt_getc_nolock.c
// Use getc to read a line from a file.

#include <stdio.h>

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

    // Read a single line from the file "crt_getc_nolock.txt".
    fopen_s(&fp, "crt_getc_nolock.txt", "r");
    if (!fp)
    {
       printf("Failed to open file crt_getc_nolock.txt.\n");
       exit(1);
    }

    for (i = 0; (i < 80) && ((ch = getc(fp)) != EOF)
                         && (ch != '\n'); i++)
    {
        buffer[i] = (char) ch;
    }

    // Terminate string with a null character
    buffer[i] = '\0';
    printf( "Input was: %s\n", buffer);

    fclose(fp);
}

Input: crt_getc_nolock.txt

Line the first.
Line the second.

Output

Input was: Line the first.

See also

Stream I/O
fgetc, fgetwc
_getch, _getwch
putc, putwc
ungetc, ungetwc