wisski-cloud-distillery/pkg/fsx/unmasked.go
2023-03-02 11:38:30 +01:00

101 lines
2.1 KiB
Go

package fsx
import (
"io/fs"
"os"
"sync"
"syscall"
"time"
)
// mask is the global mask lock
var m mask
// mask allows disabling and re-enabling the global umask.
// it is used by allow functions of this package.
type mask struct {
l sync.Mutex // locked?
umask int // previous mask
}
// Lock blocks until no other function is using this umask
// and then sets it to 0.
func (mask *mask) Lock() {
mask.l.Lock()
mask.umask = syscall.Umask(0)
}
func (mask *mask) Unlock() {
mask.umask = syscall.Umask(mask.umask)
mask.l.Unlock()
}
// WriteFile is like [os.WriteFile], but ignores the umask.
func WriteFile(path string, data []byte, mode fs.FileMode) error {
handle, err := Create(path, mode)
if err != nil {
return err
}
defer handle.Close()
if _, err := handle.Write(data); err != nil {
return err
}
return nil
}
// Create creates a new file with the given mode.
// This function ignores the umask.
func Create(path string, mode fs.FileMode) (*os.File, error) {
m.Lock()
defer m.Unlock()
return os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_TRUNC, mode)
}
// Mkdir creates a new directory with the given mode.
// This function ignores the umask.
func Mkdir(path string, mode fs.FileMode) error {
m.Lock()
defer m.Unlock()
return os.Mkdir(path, fs.ModeDir|mode)
}
// MkdirAll creates a new directory and all potentially missing parent directories.
// This function ignores the umask.
func MkdirAll(path string, mode fs.FileMode) error {
m.Lock()
defer m.Unlock()
return os.MkdirAll(path, fs.ModeDir|mode)
}
// Touch touches a file.
// It is similar to the unix 'touch' command.
//
// If the file does not exist exists, it is created using [Create].
// If the file does exist, it's access and modification times are updated to the current time.
//
// This function ignores the umask.
func Touch(path string, perm fs.FileMode) error {
if perm == 0 {
perm = DefaultFilePerm
}
_, err := os.Stat(path)
switch {
case os.IsNotExist(err):
f, err := Create(path, perm)
if err != nil {
return err
}
defer f.Close()
return nil
case err != nil:
return err
default:
now := time.Now().Local()
return os.Chtimes(path, now, now)
}
}