$ go doc io.read
func (l *LimitedReader) Read(p []byte) (n int, err error)
func (r *PipeReader) Read(data []byte) (n int, err error)

    Read implements the standard Read interface: it reads data from the pipe,
    blocking until a writer arrives or the write end is closed. If the write end
    is closed with an error, that error is returned as err; otherwise err is
    EOF.
func (s *SectionReader) Read(p []byte) (n int, err error)

$ go doc io.read
func (l *LimitedReader) Read(p []byte) (n int, err error)
func (r *PipeReader) Read(data []byte) (n int, err error)
    Read implements the standard Read interface: it reads data from the pipe,
    blocking until a writer arrives or the write end is closed. If the write end
    is closed with an error, that error is returned as err; otherwise err is
    EOF.

func (s *SectionReader) Read(p []byte) (n int, err error)

$ go doc io
package io // import "io"

Package io provides basic interfaces to I/O primitives. Its primary job is
to wrap existing implementations of such primitives, such as those in
package os, into shared public interfaces that abstract the functionality,
plus some other related primitives.

Because these interfaces and primitives wrap lower-level operations with
various implementations, unless otherwise informed clients should not assume
they are safe for parallel execution.
var EOF = errors.New("EOF")
var ErrClosedPipe = errors.New("io: read/write on closed pipe")
var ErrNoProgress = errors.New("multiple Read calls return no data or error")
...

$ go doc io
package io // import "io"

Package io provides basic interfaces to I/O primitives. Its primary job is
to wrap existing implementations of such primitives, such as those in
package os, into shared public interfaces that abstract the functionality,
plus some other related primitives.

Because these interfaces and primitives wrap lower-level operations with
various implementations, unless otherwise informed clients should not assume
they are safe for parallel execution.

var EOF = errors.New("EOF")
var ErrClosedPipe = errors.New("io: read/write on closed pipe")
var ErrNoProgress = errors.New("multiple Read calls return no data or error")
...