メモメモ os.Stdout
// os.Stdout implements Writer
w = os.Stdout
fmt.Fprintf(w, "hello, writer\n")
-----------------------------------------------------------------------------
<- http://golang.org/pkg/os/#pkg-variables
Package os
Variables
var ( Stdin = NewFile(uintptr(syscall.Stdin), "/dev/stdin") Stdout = NewFile(uintptr(syscall.Stdout), "/dev/stdout") Stderr = NewFile(uintptr(syscall.Stderr), "/dev/stderr") )
Stdin, Stdout, and Stderr are open Files pointing to the standard input, standard output, and standard error file descriptors.
<- http://golang.org/pkg/os/#NewFile
func NewFile
func NewFile(fd uintptr, name string) *File
NewFile returns a new File with the given file descriptor and name.
type File
type File struct {
// contains filtered or unexported fields
}
File represents an open file descriptor.
func (*File) Write
func (f *File) Write(b []byte) (n int, err error)
Write writes len(b) bytes to the File. It returns the number of bytes written and an error, if any. Write returns a non-nil error when n != len(b).
<- syscall - The Go Programming Language
Package syscall
Overview ▾
Package syscall contains an interface to the low-level operating system primitives. The details vary depending on the underlying system, and by default, godoc will display the syscall documentation for the current system.
<- http://golang.org/pkg/syscall/#pkg-variables
Variables
var ( Stdin = 0 Stdout = 1 Stderr = 2 )
<- https://golang.org/pkg/fmt/#Fprintf
func Fprintf
func Fprintf(w io.Writer, format string, a ...interface{}) (n int, err error)
Fprintf formats according to a format specifier and writes to w. It returns the number of bytes written and any write error encountered.
<- http://golang.org/pkg/io/#Writer
Package io
type Writer
type Writer interface { Write(p []byte) (n int, err error) }
Writer is the interface that wraps the basic Write method.
Write writes len(p) bytes from p to the underlying data stream. It returns the number of bytes written from p (0 <= n <= len(p)) and any error encountered that caused the write to stop early. Write must return a non-nil error if it returns n < len(p). Write must not modify the slice data, even temporarily.
<- http://golang.org/pkg/syscall/#Write
func Write
func Write(fd int, p []byte) (n int, err error)
<- https://golang.org/src/syscall/syscall_unix.go
148 func Write(fd int, p []byte) (n int, err error) {
149 if raceenabled {
150 raceReleaseMerge(unsafe.Pointer(&ioSync))
151 }
152 n, err = write(fd, p)
153 if raceenabled && n > 0 {
154 raceReadRange(unsafe.Pointer(&p[0]), n)
155 }
156 return
157 }