| // 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. |
| |
| // +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris windows |
| |
| package os |
| |
| import ( |
| "syscall" |
| "time" |
| ) |
| |
| func sigpipe() // implemented in package runtime |
| |
| // Readlink returns the destination of the named symbolic link. |
| // If there is an error, it will be of type *PathError. |
| func Readlink(name string) (string, error) { |
| for len := 128; ; len *= 2 { |
| b := make([]byte, len) |
| n, e := fixCount(syscall.Readlink(name, b)) |
| if e != nil { |
| return "", &PathError{"readlink", name, e} |
| } |
| if n < len { |
| return string(b[0:n]), nil |
| } |
| } |
| } |
| |
| // syscallMode returns the syscall-specific mode bits from Go's portable mode bits. |
| func syscallMode(i FileMode) (o uint32) { |
| o |= uint32(i.Perm()) |
| if i&ModeSetuid != 0 { |
| o |= syscall.S_ISUID |
| } |
| if i&ModeSetgid != 0 { |
| o |= syscall.S_ISGID |
| } |
| if i&ModeSticky != 0 { |
| o |= syscall.S_ISVTX |
| } |
| // No mapping for Go's ModeTemporary (plan9 only). |
| return |
| } |
| |
| // Chmod changes the mode of the named file to mode. |
| // If the file is a symbolic link, it changes the mode of the link's target. |
| // If there is an error, it will be of type *PathError. |
| func Chmod(name string, mode FileMode) error { |
| if e := syscall.Chmod(name, syscallMode(mode)); e != nil { |
| return &PathError{"chmod", name, e} |
| } |
| return nil |
| } |
| |
| // Chmod changes the mode of the file to mode. |
| // If there is an error, it will be of type *PathError. |
| func (f *File) Chmod(mode FileMode) error { |
| if f == nil { |
| return ErrInvalid |
| } |
| if e := syscall.Fchmod(f.fd, syscallMode(mode)); e != nil { |
| return &PathError{"chmod", f.name, e} |
| } |
| return nil |
| } |
| |
| // Chown changes the numeric uid and gid of the named file. |
| // If the file is a symbolic link, it changes the uid and gid of the link's target. |
| // If there is an error, it will be of type *PathError. |
| func Chown(name string, uid, gid int) error { |
| if e := syscall.Chown(name, uid, gid); e != nil { |
| return &PathError{"chown", name, e} |
| } |
| return nil |
| } |
| |
| // Lchown changes the numeric uid and gid of the named file. |
| // If the file is a symbolic link, it changes the uid and gid of the link itself. |
| // If there is an error, it will be of type *PathError. |
| func Lchown(name string, uid, gid int) error { |
| if e := syscall.Lchown(name, uid, gid); e != nil { |
| return &PathError{"lchown", name, e} |
| } |
| return nil |
| } |
| |
| // Chown changes the numeric uid and gid of the named file. |
| // If there is an error, it will be of type *PathError. |
| func (f *File) Chown(uid, gid int) error { |
| if f == nil { |
| return ErrInvalid |
| } |
| if e := syscall.Fchown(f.fd, uid, gid); e != nil { |
| return &PathError{"chown", f.name, e} |
| } |
| return nil |
| } |
| |
| // Truncate changes the size of the file. |
| // It does not change the I/O offset. |
| // If there is an error, it will be of type *PathError. |
| func (f *File) Truncate(size int64) error { |
| if f == nil { |
| return ErrInvalid |
| } |
| if e := syscall.Ftruncate(f.fd, size); e != nil { |
| return &PathError{"truncate", f.name, e} |
| } |
| return nil |
| } |
| |
| // Sync commits the current contents of the file to stable storage. |
| // Typically, this means flushing the file system's in-memory copy |
| // of recently written data to disk. |
| func (f *File) Sync() (err error) { |
| if f == nil { |
| return ErrInvalid |
| } |
| if e := syscall.Fsync(f.fd); e != nil { |
| return NewSyscallError("fsync", e) |
| } |
| return nil |
| } |
| |
| // Chtimes changes the access and modification times of the named |
| // file, similar to the Unix utime() or utimes() functions. |
| // |
| // The underlying filesystem may truncate or round the values to a |
| // less precise time unit. |
| // If there is an error, it will be of type *PathError. |
| func Chtimes(name string, atime time.Time, mtime time.Time) error { |
| var utimes [2]syscall.Timespec |
| utimes[0] = syscall.NsecToTimespec(atime.UnixNano()) |
| utimes[1] = syscall.NsecToTimespec(mtime.UnixNano()) |
| if e := syscall.UtimesNano(name, utimes[0:]); e != nil { |
| return &PathError{"chtimes", name, e} |
| } |
| return nil |
| } |