# System-Level I/O
> **Quote**
> I think the major good idea in Unix was its clean and simple interface: open, close, read, and write.
>
> by Ken Thompson
10.1 - 10.5 visit book
10.6 - 10.10 visit here
## test
code directory: `./code`
test way:
- assert means assert function from ``
- output means to watch code output to judge if it works right
|solution|code file|test way|
|:------:|:-------:|:------:|
|10.6|10.6.c|output|
|10.7|10.7.c|output|
|10.8|10.8.c|output|
|10.9|----|----|
|10.10|10.10.c|output|
