moby/pkg/longpath/longpath.go
Sebastiaan van Stijn c63ea32a17
pkg/ioutils: TempDir: move to pkg/longpath
This utility wasn't very related to all other utilities in pkg/ioutils.
Moving it to longpath to also make it more clear what it does.

It looks like there's only a single (public) external consumer of this
utility, and only used in a test, and it's not 100% clear if it was
intentional to use our package, of if it was a case of "I actually meant
`io/ioutil.MkdirTemp`" so we could consider skipping the alias.

While moving the package, I also renamed `TempDir` to `MkdirTemp`, which
is the signature it matches in "os" from stdlib.

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
2022-12-20 23:24:12 +01:00

43 lines
1.2 KiB
Go

// Package longpath introduces some constants and helper functions for handling
// long paths in Windows.
//
// Long paths are expected to be prepended with "\\?\" and followed by either a
// drive letter, a UNC server\share, or a volume identifier.
package longpath // import "github.com/docker/docker/pkg/longpath"
import (
"os"
"runtime"
"strings"
)
// Prefix is the longpath prefix for Windows file paths.
const Prefix = `\\?\`
// AddPrefix adds the Windows long path prefix to the path provided if
// it does not already have it.
func AddPrefix(path string) string {
if !strings.HasPrefix(path, Prefix) {
if strings.HasPrefix(path, `\\`) {
// This is a UNC path, so we need to add 'UNC' to the path as well.
path = Prefix + `UNC` + path[1:]
} else {
path = Prefix + path
}
}
return path
}
// MkdirTemp is the equivalent of [os.MkdirTemp], except that on Windows
// the result is in Windows longpath format. On Unix systems it is
// equivalent to [os.MkdirTemp].
func MkdirTemp(dir, prefix string) (string, error) {
tempDir, err := os.MkdirTemp(dir, prefix)
if err != nil {
return "", err
}
if runtime.GOOS != "windows" {
return tempDir, nil
}
return AddPrefix(tempDir), nil
}