以下哪些命令能找到文件file1和file2不同之处并显示出来:()A. cmp file1 file2B. diff file1 file2C. more file1 file2

下列程序用于将源文件中的字母进行大小写转换，while的条件是【 】。

include＜iostream. h＞

include＜fstream. h＞

include＜iomanip. h＞

void main( )

}

char ch;

fstream filel, file2

char fn1[10], fn2[10];

cout＜＜"输入源文件名:";

cin＞＞fn1

cout＜＜"输入目标文件名:";

tin＞＞fn2

file1, open(fn1 ,ios: :in);

file2, open(fn2, ios:: out);

while(________)

{

if(ch＞='a'&&ch＜='z')

ch=ch-'a'+'A',

file2, put(ch),

}

file1, close(),

file2, close();

}