Musical notation was conceived for the C major scale and each line and space represents a note in this scale.
乐谱为C大音阶而构思，在这个音阶中的每一个线和间都代表一个音符。
《柯林斯英汉双解大词典》
2
The language was added in recent years to draw a clear line. It’s easy for students to point to this notation and say “Hey, Mom, I think you’re supposed to be gone now”.
这些语言可以说是划出一条明确界限，学生可以指着这些文字对家长说：“瞧，妈妈，您该走了吧。”
3
You can use the $ notation for the last line to specify to the end of the file and double greater-than symbols (>>) after the w to indicate that you want to append to rather than overwrite the file.
对于最后一行，可以使用 $ 表示文件的末尾。 可以在 w 后面使用两个大于号（>>）表示希望把内容附加到文件中而不是覆盖文件。