当所有数据全部写入之后，就需要设置eof(文件结束参数)。

When all the data have been written, set the eof (end-of-file) argument.

youdao

ignoree of：忽略文件结束字符，并且不退出shell。

Ignoreeof: ignore end-of-file characters, and do not exit the shell.

youdao

可是，也有一些忧虑是出自一些使用数字9999标记文件结束的数字系统。

But there were also worries because some data systems used the digits 9999 to mark the end of a file.

youdao