go/doc/progs/file.go
Rob Pike 7839521335 Automated g4 rollback of changelist 35383.
*** Reason for rollback ***

roll back the changes to the tutorial programs (only) since they
break the automated processing used to create the tutorial.

*** Original change description ***

apply gofmt to the LGTM-marked files from 34501
that have not changed since I applied gofmt.

R=rsc
DELTA=139  (0 added, 44 deleted, 95 changed)
OCL=35670
CL=35670
2009-10-13 12:37:04 -07:00

75 lines
1.3 KiB
Go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package file
import (
"os";
"syscall";
)
type File struct {
fd int; // file descriptor number
name string; // file name at Open time
}
func newFile(fd int, name string) *File {
if fd < 0 {
return nil
}
return &File{fd, name}
}
var (
Stdin = newFile(0, "/dev/stdin");
Stdout = newFile(1, "/dev/stdout");
Stderr = newFile(2, "/dev/stderr");
)
func Open(name string, mode int, perm int) (file *File, err os.Error) {
r, e := syscall.Open(name, mode, perm);
if e != 0 {
err = os.Errno(e);
}
return newFile(r, name), err
}
func (file *File) Close() os.Error {
if file == nil {
return os.EINVAL
}
e := syscall.Close(file.fd);
file.fd = -1; // so it can't be closed again
if e != 0 {
return os.Errno(e);
}
return nil
}
func (file *File) Read(b []byte) (ret int, err os.Error) {
if file == nil {
return -1, os.EINVAL
}
r, e := syscall.Read(file.fd, b);
if e != 0 {
err = os.Errno(e);
}
return int(r), err
}
func (file *File) Write(b []byte) (ret int, err os.Error) {
if file == nil {
return -1, os.EINVAL
}
r, e := syscall.Write(file.fd, b);
if e != 0 {
err = os.Errno(e);
}
return int(r), err
}
func (file *File) String() string {
return file.name
}