memset

Function Usage

Set data of a specified length in the destination memory to a specified value.

Function Syntax

void *memset(void *destination, int value, size_t size);

Parameters

Parameter	Description	Value Range	Input/Output
destination	Pointer to the destination memory used to store the reset data.	The value cannot be NULL.	Output
value	Target value.	The value is not limited.	Input
size	Number of bytes to be reset.	The value cannot be negative.	Input

Return Value

Success: A pointer to the destination memory is returned.
Failure: A null pointer is returned.

Example

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "kqmalloc.h"

#define KQMALLOC_TEST_LEN 10

void MemsetExample()
{
    int8_t *destination = (int8_t *)malloc(KQMALLOC_TEST_LEN * sizeof(int8_t));
    if (destination == NULL) {
        printf("destination is null\n");
        return;
    } else {
        printf("destination address: %lx\n", destination);
        for (int8_t i = 0; i < KQMALLOC_TEST_LEN; ++i) {
            destination[i] = i;
        }
        printf("destination test data before memcpy:");
        for (int8_t i = 0; i < KQMALLOC_TEST_LEN; ++i) {
            printf(" %d", destination[i]);
        }
        printf("\n");
    }
    int8_t *res = memset(destination , 1, KQMALLOC_TEST_LEN * sizeof(int8_t));
    printf("res address: %lx\n", res);
    if (res != NULL) {
        printf("res test data after memcpy:");
        for (int8_t i = 0; i < KQMALLOC_TEST_LEN; ++i) {
            printf(" %d", res[i]);
        }
        printf("\n");
    }

    free(destination);
}

int main(void) {
    MemsetExample();
    return 0;
}

Output:

destination address: ffff9fe17174
destination test data before memcpy: 0 1 2 3 4 5 6 7 8 9
res address: ffff9fe17174
res test data after memcpy: 1 1 1 1 1 1 1 1 1 1

Parent topic: Function Syntax