lesson3.md

Lesson 3: Command Line Applications

In this lesson, we will implement several common unix commands in Go.

• The commands
  • cat - copy input to standard output | 15 minutes
  • head - ouput the first part of files | 15 minutes
  • tail - ouput the last part of files | 15 minutes
  • tac - copy input to standard output in reverse | 15 minutes

cat - copy input to standard output

• go get lesson3/go-cat-01

• go test lesson3/go-cat-01

• reading from standard input

• reading from a file

• writing to standard output

• io package

  • io.Reader
  • io.Writer

• The os package

  • io.Reader
  • io.Writer

head - ouput the first part of files

tail - ouput the last part of files

tac - copy input to standard output in reverse