mirror of
https://github.com/golang/go
synced 2024-11-12 00:30:22 -07:00
a0bcaf4c00
echo back context of call in error if likely to be useful.
For example, if os.Open("/etc/passwd", os.O_RDONLY)
fails with syscall.EPERM, it returns as the os.Error
&PathError{
Op: "open",
Path: "/etc/passwd"
Error: os.EPERM
}
which formats as
open /etc/passwd: permission denied
Not converted:
datafmt
go/...
google/...
regexp
tabwriter
template
R=r
DELTA=1153 (561 added, 156 deleted, 436 changed)
OCL=30738
CL=30781
75 lines
1.3 KiB
Go
75 lines
1.3 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package file
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import (
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"os";
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"syscall";
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)
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type File struct {
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fd int; // file descriptor number
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name string; // file name at Open time
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}
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func newFile(fd int, name string) *File {
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if fd < 0 {
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return nil
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}
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return &File{fd, name}
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}
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var (
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Stdin = newFile(0, "/dev/stdin");
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Stdout = newFile(1, "/dev/stdout");
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Stderr = newFile(2, "/dev/stderr");
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)
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func Open(name string, mode int, perm int) (file *File, err os.Error) {
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r, e := syscall.Open(name, mode, perm);
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if e != 0 {
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err = os.Errno(e);
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}
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return newFile(r, name), err
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}
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func (file *File) Close() os.Error {
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if file == nil {
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return os.EINVAL
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}
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e := syscall.Close(file.fd);
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file.fd = -1; // so it can't be closed again
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if e != 0 {
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return os.Errno(e);
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}
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return nil
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}
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func (file *File) Read(b []byte) (ret int, err os.Error) {
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if file == nil {
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return -1, os.EINVAL
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}
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r, e := syscall.Read(file.fd, b);
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if e != 0 {
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err = os.Errno(e);
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}
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return int(r), err
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}
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func (file *File) Write(b []byte) (ret int, err os.Error) {
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if file == nil {
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return -1, os.EINVAL
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}
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r, e := syscall.Write(file.fd, b);
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if e != 0 {
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err = os.Errno(e);
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}
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return int(r), err
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}
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func (file *File) String() string {
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return file.name
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}
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