| 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. |
| encoding/json | Package json implements encoding and decoding of JSON as defined in RFC 7159. |
| errors | Package errors implements functions to manipulate errors. |
| flag | Package flag implements command-line flag parsing. |
| fmt | Package fmt implements formatted I/O with functions analogous to C's printf and scanf. |
| go/version | Package version provides operations on [Go versions] in [Go toolchain name syntax]: strings like "go1.20", "go1.21.0", "go1.22rc2", and "go1.23.4-bigcorp". |
| io | Package io provides basic interfaces to I/O primitives. |
| io/fs | Package fs defines basic interfaces to a file system. |
| log | Package log implements a simple logging package. |
| os | Package os provides a platform-independent interface to operating system functionality. |
| os/exec | Package exec runs external commands. |
| path | Package path implements utility routines for manipulating slash-separated paths. |
| 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. |
| regexp | Package regexp implements regular expression search. |
| runtime | Package runtime contains operations that interact with Go's runtime system, such as functions to control goroutines. |
| sort | Package sort provides primitives for sorting slices and user-defined collections. |
| 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. |
| sync | Package sync provides basic synchronization primitives such as mutual exclusion locks. |
| syscall | Package syscall contains an interface to the low-level operating system primitives. |
| time | Package time provides functionality for measuring and displaying time. |
| unicode/utf8 | Package utf8 implements functions and constants to support text encoded in UTF-8. |
| unsafe | Package unsafe contains operations that step around the type safety of Go programs. |