用C语言编写程序，将输入文件的各行逆序显示在标准输出上。如果不指定文件名，则逆序显示标准输入的内容。当使用-c选项时，每一行的字符也逆序输出。

标准输入以CTRL+D表示结束。使用系统调用.-With the C programming language, each line of the input file to standard output in reverse order. If you do not specify a file name, display the standard input in reverse order. When using the-c option, the character of each line is also reverse the output. CTRL+ D standard input to that end. Use of system calls.