| bufio | Package bufio implements buffered I/O. It wraps an io.Reader or io.Writer object, creating another object (Reader or Writer) that also implements the interface but provides buffering and some help for textual I/O. |
| bytes | Package bytes implements functions for the manipulation of byte slices. |
| crypto/rand | Package rand implements a cryptographically secure random number generator. |
| errors | Package errors implements functions to manipulate errors. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| internal/godebug | Package godebug makes the settings in the $GODEBUG environment variable available to other packages. |
| io | Package io provides basic interfaces to I/O primitives. |
| math | Package math provides basic constants and mathematical functions. |
| mime | Package mime implements parts of the MIME spec. |
| mime/quotedprintable | Package quotedprintable implements quoted-printable encoding as specified by RFC 2045. |
| net/textproto | Package textproto implements generic support for text-based request/response protocols in the style of HTTP, NNTP, and SMTP. |
| 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. |
| slices | Package slices defines various functions useful with slices of any type. |
| 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. |
| unsafe | Package unsafe contains operations that step around the type safety of Go programs. |