Feature request: Being able to

[zveinn]

Hello again!

Yet again I find myself using godirwalk, just love this module <3

I was wondering if you could implement a way to detect if the current runtime does not have permissions to enter a folder.

Right now the Walk method just throws an error if I don't have permissions:

$ goto [DIRECTORY]
2021/03/29 08:37:55 trying: .
2021/03/29 08:37:55 trying: $Recycle.Bin
2021/03/29 08:37:55 trying: $Recycle.Bin/S-1-5-18
2021/03/29 08:37:55 open $Recycle.Bin/S-1-5-18: permission denied

Here is my suggestion:

Add a function called "CanAccess" or something similar, that let's you check for persmissions inside the Walk method itself. This way you can combine HasAccess with SkipThis to quickly bypass closed off directories and/or files.

Example:

func main() {
	err := godirwalk.Walk("./", &godirwalk.Options{
		Callback: func(osPathname string, info *godirwalk.Dirent) error {
			log.Println("trying:", osPathname)

			if info.CanAccess() {
				return godirwalk.SkipThis
			}

			if info.IsDir() {
				if strings.Contains(osPathname, os.Args[1]) {
					fmt.Println(osPathname)
					os.Exit(0)
				}
			}
			return nil
		},
		Unsorted: true,
	})

	if err != nil {
		// Permissions error happens here, outside the walk
		log.Println(err)
	}

	fmt.Print("no directory found")
}

I figured since you're all up in this code, you might be able to do it in a few minutes but it might take me hours :S

[zveinn]

Actually, this functionality already exists in the configurable error callback.

func main() {
	err := godirwalk.Walk(os.Args[1], &godirwalk.Options{
		Callback: func(osPathname string, info *godirwalk.Dirent) error {
			log.Println("trying:", osPathname)
			if info.IsDir() {
				if strings.Contains(osPathname, os.Args[2]) {
					fmt.Println(osPathname)
					os.Exit(0)
				}
			}

			return nil
		},
		ErrorCallback: func(osPathname string, err error) godirwalk.ErrorAction {
			// 1 means continue, not sure about the other options but we can probably assume 0 means stop ?
			return 1
		},
		// Unsorted: true,
	})

	if err != nil {
		// Permissions error happens here, outside the walk
		log.Println(err)
	}

	fmt.Print("no directory found")

}

My only recommendation at this point is to maybe move the documentation about the callback higher up in the readme and maybe define what the godirwalk.ErrorAction options are ? maybe even add a code sample ?

[GwynethLlewelyn]

For the sake of completeness and consistency, instead of the "return 1" on the error callback, use either:

godirwalk.Halt       // set to iota, i.e. 0
godirwalk.SkipNode   // set to value next to iota, i.e. 1

At the time of writing this comment, no further options are being defined.

See https://github.com/karrick/godirwalk/blob/master/walk.go#L90 (note: line number may change depending on the version)