===== bufio package =====

==== What is it? ====
`bufio` implements **buffered I/O** by wrapping an `io.Reader` or `io.Writer` and using an in-memory buffer to make reading/writing more efficient.

==== What is it used for? ====
  * Faster reading/writing for files and network connections.
  * Convenient scanning of lines/tokens (`bufio.Scanner`).
  * Convenient line-based reads (`ReadString`, `ReadBytes`).

==== Common types ====
  * `bufio.Reader`: buffered reader
  * `bufio.Writer`: buffered writer
  * `bufio.Scanner`: token/line scanner

==== Example: buffered reading (lines) ====
<code go>
r := bufio.NewReader(f)
line, err := r.ReadString('\n')
_ = line
_ = err
</code>

==== Example: buffered writing ====
<code go>
w := bufio.NewWriter(f)
_, _ = w.WriteString("hello\n")
_ = w.Flush()
</code>

==== Notes / pitfalls ====
  * Always call `Flush()` on `bufio.Writer` to ensure data is written.
  * `Scanner` has a token size limit by default; for big lines, configure buffer or use `Reader`.

==== Related pages ====
  * [[go:stdlib:io|io package]]
  * [[go:stdlib:os_open|os.Open]]
  * [[go:stdlib:net_dial|net.Dial]]

==== Hard words (English) ====
  * **buffer** /ˈbʌfər/: bộ đệm
  * **wrap** /ræp/: bọc
  * **efficient** /ɪˈfɪʃənt/: hiệu quả
  * **flush** /flʌʃ/: đẩy hết dữ liệu trong buffer ra nơi ghi
  * **token** /ˈtoʊkən/: đơn vị tách (mảnh dữ liệu)