blob: 6cf26614066ed6bc225bcb9099cf44d71b36c0d8 [file] [log] [blame]
// 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.
// The os package provides a platform-independent interface to operating
// system functionality. The design is Unix-like.
package os
import (
"runtime"
"syscall"
)
// Auxiliary information if the File describes a directory
type dirInfo struct {
buf []byte // buffer for directory I/O
nbuf int // length of buf; return value from Getdirentries
bufp int // location of next record in buf.
}
// Open opens the named file with specified flag (O_RDONLY etc.) and perm, (0666 etc.)
// if applicable. If successful, methods on the returned File can be used for I/O.
// It returns the File and an Error, if any.
func Open(name string, flag int, perm int) (file *File, err Error) {
r, e := syscall.Open(name, flag|syscall.O_CLOEXEC, perm)
if e != 0 {
return nil, &PathError{"open", name, Errno(e)}
}
// There's a race here with fork/exec, which we are
// content to live with. See ../syscall/exec.go
if syscall.O_CLOEXEC == 0 { // O_CLOEXEC not supported
syscall.CloseOnExec(r)
}
return NewFile(r, name), nil
}
// Close closes the File, rendering it unusable for I/O.
// It returns an Error, if any.
func (file *File) Close() Error {
if file == nil || file.fd < 0 {
return EINVAL
}
var err Error
if e := syscall.Close(file.fd); e != 0 {
err = &PathError{"close", file.name, Errno(e)}
}
file.fd = -1 // so it can't be closed again
// no need for a finalizer anymore
runtime.SetFinalizer(file, nil)
return err
}
// Stat returns the FileInfo structure describing file.
// It returns the FileInfo and an error, if any.
func (file *File) Stat() (fi *FileInfo, err Error) {
var stat syscall.Stat_t
e := syscall.Fstat(file.fd, &stat)
if e != 0 {
return nil, &PathError{"stat", file.name, Errno(e)}
}
return fileInfoFromStat(file.name, new(FileInfo), &stat, &stat), nil
}
// Readdir reads the contents of the directory associated with file and
// returns an array of up to count FileInfo structures, as would be returned
// by Stat, in directory order. Subsequent calls on the same file will yield
// further FileInfos.
// A negative count means to read until EOF.
// Readdir returns the array and an Error, if any.
func (file *File) Readdir(count int) (fi []FileInfo, err Error) {
dirname := file.name
if dirname == "" {
dirname = "."
}
dirname += "/"
names, err1 := file.Readdirnames(count)
if err1 != nil {
return nil, err1
}
fi = make([]FileInfo, len(names))
for i, filename := range names {
fip, err := Lstat(dirname + filename)
if fip == nil || err != nil {
fi[i].Name = filename // rest is already zeroed out
} else {
fi[i] = *fip
}
}
return
}
// Truncate changes the size of the named file.
// If the file is a symbolic link, it changes the size of the link's target.
func Truncate(name string, size int64) Error {
if e := syscall.Truncate(name, size); e != 0 {
return &PathError{"truncate", name, Errno(e)}
}
return nil
}