# C 语言标准库函数 strncpy

/*********************************************
 * @brief 复制字符串
 * @param dest 目标地址
 * @param src 源字符串
 * @param count 最多复制的字节数
 * @return 目标地址
 ********************************************/
char* strncpy(char* restrict dest, const char* restrict src, size_t count);

#include <stdio.h>
#include <string.h>

int main(void)
{
    char dest [10];

    strncpy(dest, "hello", 10);     // count 为 10 确保 dest 不会越界
    dest[9] = 0;                    // 确保以 0 结尾
    printf("%s\n", dest);

    strncpy(dest, "Never gonna give you up.", 10);      // count 为 10 确保 dest 不会越界
    dest[9] = 0;                                        // 确保以 0 结尾
    printf("%s\n", dest);

    return 0;
}

hello
Never gon

char array[10] = "abcde";
strcpy(array + 1, array, 3); // 复制

flowchart TD
    subgraph A["开始"]
        a ~~~ b ~~~ c ~~~ d ~~~ e
    end

    subgraph B["array[0] 复制到 array[1]"]
        B1[a] ~~~ B2[a] ~~~ B3[b] ~~~ B4[c] ~~~ B5[d]
        B1 --> B2
    end

    subgraph C["array[1] 复制到 array[2]"]
        C1[a] ~~~ C2[a] ~~~ C3[a] ~~~ C4[c] ~~~ C5[d]
        C2 --> C3
    end

    subgraph D["array[2] 复制到 array[3]"]
        D1[a] ~~~ D2[a] ~~~ D3[a] ~~~ D4[a] ~~~ D5[d]
        D3 --> D4
    end

    A --> B --> C --> D 

    classDef SUB fill:#212121,color:#fefefe,stroke:#e91e63
    class A SUB
    class B SUB
    class C SUB
    class D SUB