Go function that prunes empty directories from file system hierarchy

pruneEmptyDirectories.go

package main

import (
    "fmt"
    "os"

    "github.com/karrick/godirwalk"
    "github.com/pkg/errors"
)

func pruneEmptyDirectories(osDirname string, scratchBuffer []byte) error {
    var removedDirectoryCount int
    err := godirwalk.Walk(osDirname, &godirwalk.Options{
        Unsorted:      true,
        ScratchBuffer: scratchBuffer,
        Callback: func(_ string, _ *godirwalk.Dirent) error {
            return nil // no-op while diving in
        },
        PostChildrenCallback: func(osPathname string, _ *godirwalk.Dirent) error {
            // fmt.Fprintf(os.Stderr, "# checking for empty directory: %s\n", osPathname) // DEBUG
            deChildren, err := godirwalk.ReadDirents(osPathname, scratchBuffer)
            if err != nil {
                return errors.Wrap(err, "cannot ReadDirents")
            }
            // NOTE: ReadDirents skips "." and ".."
            if len(deChildren) > 0 {
                return nil // this directory has children; no additional work here
            }
            // fmt.Fprintf(os.Stderr, "# removing empty directory: %s\n", osPathname) // DEBUG
            err = os.Remove(osPathname)
            if err == nil {
                removedDirectoryCount++
            }
            return err
        },
    })
    fmt.Fprintf(os.Stderr, "# removed %d empty directories\n", removedDirectoryCount)
    return err
}