stosb.md

description	title	ms.date	f1_keywords	helpviewer_keywords	ms.assetid
Learn more about: __stosb	__stosb	09/02/2019	__stosb	rep stosb instruction __stosb intrinsic stosb instruction	634589ed-2da3-439b-a381-a214d89bf10c

__stosb

Microsoft Specific

Generates a store string instruction (rep stosb).

Syntax

void __stosb(
   unsigned char* Destination,
   unsigned char Data,
   size_t Count
);

Parameters

Destination
[out] The destination of the operation.

Data
[in] The data to store.

Count
[in] The length of the block of bytes to write.

Requirements

Intrinsic	Architecture
__stosb	x86, x64

Header file <intrin.h>

Remarks

The result is that the character Data is written into a block of Count bytes in the Destination string.

This routine is only available as an intrinsic.

Example

// stosb.c
// processor: x86, x64
#include <stdio.h>
#include <intrin.h>

#pragma intrinsic(__stosb)

int main()
{
    unsigned char c = 0x40; /* '@' character */
    unsigned char s[] = "*********************************";

    printf_s("%s\n", s);
    __stosb((unsigned char*)s+1, c, 6);
    printf_s("%s\n", s);

}

*********************************
*@@@@@@**************************

END Microsoft Specific

See also

Compiler intrinsics