| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| github.com/chzyer/readline | Readline is a pure go implementation for GNU-Readline kind library. |
| io | Package io provides basic interfaces to I/O primitives. |
| io/ioutil | Package ioutil implements some I/O utility functions. |
| log | Package log implements a simple logging package. |
| strconv | Package strconv implements conversions to and from string representations of basic data types. |
| strings | Package strings implements simple functions to manipulate UTF-8 encoded strings. |
| time | Package time provides functionality for measuring and displaying time. |