我正在尝试用c编写一个程序来写出一些字符串、单词、字符等......该程序的要点是允许写入所有内容，但是程序的前两个字节不能包含字符“ MZ”。我是 c 和指针的新手，这是我尝试过的：
方法1：这给了我编译错误....
else if (offset == 0L){ │ write_file_at(f, "MZ", 2, BEGINNING_OF_FILE, 0L);
│ fs_print_error();
if(!strncmp(((char*)data)[0], "M", 1)){ │ printf("\n\n");
if(offset == 1L && !strncmp(((char*)data), "Z", 1)){ │
fserror = ILLEGAL_MZ; │// Printf("Test case 3, write Z first\n");
} │// write_file_at(f, "Z", 1, BEGINNING_OF_FILE+1, 0L);
} │// fs_print_error();
} │// write_file_at(f, "M", 1, BEGINNING_OF_FILE, 0L);
│// fs_print_error();
else if (offset == 1L){ │
│
if(!strncmp(((char*)data), "Z", 1)){ │
if(offset == 0L && !strncmp(((char*)data), "M", 1)){ │ printf("Closing file...\n");
fserror = ILLEGAL_MZ; │ close_file(f);
} │ fs_print_error();
} │ return 0;
}
这是我没有运气尝试过的另一件事（至少它遵守了哈哈哈）：
char *ptr = NULL; │ char *buffer = (char*) data;
read_file_from(file, ptr, 2, BEGINNING_OF_FILE, 0L); │ printf("Test case: mz is lower cased\n");
char *buffer2 = (char*) ptr;//data already written in file │ write_file_at(f, "mz", 2, BEGINNING_OF_FILE, 0L);
│ fs_print_error();
│ printf("\n\n");
if(buffer2[0] == 'M'){ │
if(buffer[1] == 'Z'){ │
fserror = ILLEGAL_MZ; │ Test Case
} │ printf("Test case: write Z in the second byte first, then write M in the first byte\n");
} │ write_file_at(f, "Z", 1, BEGINNING_OF_FILE, 1L);
if(buffer2[0] == 'M'){ │ fs_print_error();
if(buffer[1] == 'Z'){ │ write_file_at(f, "MZ", 2, BEGINNING_OF_FILE, 0L);
fserror = ILLEGAL_MZ; │ fs_print_error();
} │ printf("\n\n");
}
*这里还要注意read_file_from是我教授给的方法，这里是参数：
unsigned long read_file_from(File file, void *data, unsigned long num_bytes, SeekAnchor start, long offset)
任何帮助将不胜感激，谢谢！
顺便说一句，Linux 用户不应该喝酒和 root！