| bytes | Package bytes implements functions for the manipulation of byte slices. |
| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| path/filepath | Package filepath implements utility routines for manipulating filename paths in a way compatible with the target operating system-defined file paths. |
| reflect | Package reflect implements run-time reflection, allowing a program to manipulate objects with arbitrary types. |
| sort | Package sort provides primitives for sorting slices and user-defined collections. |
| syscall | Package syscall contains an interface to the low-level operating system primitives. |
| unsafe | Package unsafe contains operations that step around the type safety of Go programs. |