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C stdio fwrite() 函数

❮ C stdio 库


示例

将内容写入文件

FILE *fptr;
fptr = fopen("filename.txt", "a");

char content = "Hello World!";
fwrite(content, 1, 12, fptr);
printf("%d", position);

fclose(fptr);

定义和用法

The fwrite() 函数将数据从内存块写入文件。

The fwrite() 函数在 <stdio.h> 头文件中定义。


语法

fwrite(const void * source, size_t size, size_t amount, FILE * fptr);

The size_t 数据类型是一个非负整数。

参数值

参数 描述
source 必填。指向要从中复制数据的内存块的指针。
size 必填。内存块中元素的大小。
amount 必填。要从内存块读取并写入文件的元素数量。
fptr 必填。文件指针,通常由 fopen() 函数创建。

技术细节

返回值 一个 size_t 值,表示写入文件的元素数量。

❮ C stdio 库

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