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copyfile.go
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/
copyfile.go
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package copyfile
import (
"fmt"
"syscall"
"unsafe"
)
var (
modkernel32 = syscall.NewLazyDLL("kernel32.dll")
procCopyFileW = modkernel32.NewProc("CopyFileW")
)
// CopyFile is a utility for copying a file - used for the LCOW scratch cache.
// Uses CopyFileW win32 API for performance.
func CopyFile(srcFile, destFile string, overwrite bool) error {
var bFailIfExists uint32 = 1
if overwrite {
bFailIfExists = 0
}
lpExistingFileName, err := syscall.UTF16PtrFromString(srcFile)
if err != nil {
return err
}
lpNewFileName, err := syscall.UTF16PtrFromString(destFile)
if err != nil {
return err
}
r1, _, err := syscall.Syscall(
procCopyFileW.Addr(),
3,
uintptr(unsafe.Pointer(lpExistingFileName)),
uintptr(unsafe.Pointer(lpNewFileName)),
uintptr(bFailIfExists))
if r1 == 0 {
return fmt.Errorf("failed CopyFileW Win32 call from '%s' to '%s': %s", srcFile, destFile, err)
}
return nil
}