fread只有.PNG文件的前5个字节

size_t fread(void *ptr, size_t size, size_t count, FILE *stream);

#include <stdio.h>

int main() {
    FILE *file = fopen("file.png", "rb");  // 以二进制模式打开PNG文件
    if (file == NULL) {
        printf("文件打开失败\n");
        return 1;
    }

    unsigned char buffer[5];  // 存储读取的数据
    size_t bytesRead = fread(buffer, sizeof(unsigned char), 5, file);
    if (bytesRead != 5) {
        printf("读取文件失败\n");
        return 1;
    }

    // 打印读取的数据
    for (int i = 0; i < 5; i++) {
        printf("%02X ", buffer[i]);
    }
    printf("\n");

    fclose(file);  // 关闭文件

    return 0;
}