k3s/vendor/github.com/mrunalp/fileutils/fileutils.go
2019-12-15 23:28:25 -07:00

159 lines
3.3 KiB
Go

package fileutils
import (
"fmt"
"io"
"os"
"path/filepath"
"syscall"
)
// CopyFile copies the file at source to dest
func CopyFile(source string, dest string) error {
si, err := os.Lstat(source)
if err != nil {
return err
}
st, ok := si.Sys().(*syscall.Stat_t)
if !ok {
return fmt.Errorf("could not convert to syscall.Stat_t")
}
uid := int(st.Uid)
gid := int(st.Gid)
// Handle symlinks
if si.Mode()&os.ModeSymlink != 0 {
target, err := os.Readlink(source)
if err != nil {
return err
}
if err := os.Symlink(target, dest); err != nil {
return err
}
}
// Handle device files
if st.Mode&syscall.S_IFMT == syscall.S_IFBLK || st.Mode&syscall.S_IFMT == syscall.S_IFCHR {
devMajor := int64(major(uint64(st.Rdev)))
devMinor := int64(minor(uint64(st.Rdev)))
mode := uint32(si.Mode() & 07777)
if st.Mode&syscall.S_IFMT == syscall.S_IFBLK {
mode |= syscall.S_IFBLK
}
if st.Mode&syscall.S_IFMT == syscall.S_IFCHR {
mode |= syscall.S_IFCHR
}
if err := syscall.Mknod(dest, mode, int(mkdev(devMajor, devMinor))); err != nil {
return err
}
}
// Handle regular files
if si.Mode().IsRegular() {
sf, err := os.Open(source)
if err != nil {
return err
}
defer sf.Close()
df, err := os.Create(dest)
if err != nil {
return err
}
defer df.Close()
_, err = io.Copy(df, sf)
if err != nil {
return err
}
}
// Chown the file
if err := os.Lchown(dest, uid, gid); err != nil {
return err
}
// Chmod the file
if !(si.Mode()&os.ModeSymlink == os.ModeSymlink) {
if err := os.Chmod(dest, si.Mode()); err != nil {
return err
}
}
return nil
}
// CopyDirectory copies the files under the source directory
// to dest directory. The dest directory is created if it
// does not exist.
func CopyDirectory(source string, dest string) error {
fi, err := os.Stat(source)
if err != nil {
return err
}
// Get owner.
st, ok := fi.Sys().(*syscall.Stat_t)
if !ok {
return fmt.Errorf("could not convert to syscall.Stat_t")
}
// We have to pick an owner here anyway.
if err := MkdirAllNewAs(dest, fi.Mode(), int(st.Uid), int(st.Gid)); err != nil {
return err
}
return filepath.Walk(source, func(path string, info os.FileInfo, err error) error {
if err != nil {
return err
}
// Get the relative path
relPath, err := filepath.Rel(source, path)
if err != nil {
return nil
}
if info.IsDir() {
// Skip the source directory.
if path != source {
// Get the owner.
st, ok := info.Sys().(*syscall.Stat_t)
if !ok {
return fmt.Errorf("could not convert to syscall.Stat_t")
}
uid := int(st.Uid)
gid := int(st.Gid)
if err := os.Mkdir(filepath.Join(dest, relPath), info.Mode()); err != nil {
return err
}
if err := os.Lchown(filepath.Join(dest, relPath), uid, gid); err != nil {
return err
}
}
return nil
}
return CopyFile(path, filepath.Join(dest, relPath))
})
}
// Gives a number indicating the device driver to be used to access the passed device
func major(device uint64) uint64 {
return (device >> 8) & 0xfff
}
// Gives a number that serves as a flag to the device driver for the passed device
func minor(device uint64) uint64 {
return (device & 0xff) | ((device >> 12) & 0xfff00)
}
func mkdev(major int64, minor int64) uint32 {
return uint32(((minor & 0xfff00) << 12) | ((major & 0xfff) << 8) | (minor & 0xff))
}