| // 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(fixLongPath(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 |
| } |
| |
| // See docs in file.go:Chmod. |
| func chmod(name string, mode FileMode) error { |
| if e := syscall.Chmod(fixLongPath(name), syscallMode(mode)); e != nil { |
| return &PathError{"chmod", name, e} |
| } |
| return nil |
| } |
| |
| // See docs in file.go:(*File).Chmod. |
| func (f *File) chmod(mode FileMode) error { |
| if err := f.checkValid("chmod"); err != nil { |
| return err |
| } |
| if e := f.pfd.Fchmod(syscallMode(mode)); e != nil { |
| return f.wrapErr("chmod", 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. |
| // A uid or gid of -1 means to not change that value. |
| // If there is an error, it will be of type *PathError. |
| // |
| // On Windows or Plan 9, Chown always returns the syscall.EWINDOWS or |
| // EPLAN9 error, wrapped in *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. |
| // |
| // On Windows, it always returns the syscall.EWINDOWS error, wrapped |
| // in *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. |
| // |
| // On Windows, it always returns the syscall.EWINDOWS error, wrapped |
| // in *PathError. |
| func (f *File) Chown(uid, gid int) error { |
| if err := f.checkValid("chown"); err != nil { |
| return err |
| } |
| if e := f.pfd.Fchown(uid, gid); e != nil { |
| return f.wrapErr("chown", 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 err := f.checkValid("truncate"); err != nil { |
| return err |
| } |
| if e := f.pfd.Ftruncate(size); e != nil { |
| return f.wrapErr("truncate", 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() error { |
| if err := f.checkValid("sync"); err != nil { |
| return err |
| } |
| if e := f.pfd.Fsync(); e != nil { |
| return f.wrapErr("sync", 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(fixLongPath(name), utimes[0:]); e != nil { |
| return &PathError{"chtimes", name, e} |
| } |
| return nil |
| } |
| |
| // Chdir changes the current working directory to the file, |
| // which must be a directory. |
| // If there is an error, it will be of type *PathError. |
| func (f *File) Chdir() error { |
| if err := f.checkValid("chdir"); err != nil { |
| return err |
| } |
| if e := f.pfd.Fchdir(); e != nil { |
| return f.wrapErr("chdir", e) |
| } |
| return nil |
| } |
| |
| // setDeadline sets the read and write deadline. |
| func (f *File) setDeadline(t time.Time) error { |
| if err := f.checkValid("SetDeadline"); err != nil { |
| return err |
| } |
| return f.pfd.SetDeadline(t) |
| } |
| |
| // setReadDeadline sets the read deadline. |
| func (f *File) setReadDeadline(t time.Time) error { |
| if err := f.checkValid("SetReadDeadline"); err != nil { |
| return err |
| } |
| return f.pfd.SetReadDeadline(t) |
| } |
| |
| // setWriteDeadline sets the write deadline. |
| func (f *File) setWriteDeadline(t time.Time) error { |
| if err := f.checkValid("SetWriteDeadline"); err != nil { |
| return err |
| } |
| return f.pfd.SetWriteDeadline(t) |
| } |
| |
| // checkValid checks whether f is valid for use. |
| // If not, it returns an appropriate error, perhaps incorporating the operation name op. |
| func (f *File) checkValid(op string) error { |
| if f == nil { |
| return ErrInvalid |
| } |
| return nil |
| } |