toying with uru's .ruby-version searching impl

uru_dirwalkup.go

package main

import (
	"fmt"
	"os"
	"path/filepath"
	"runtime"
	"strings"
)

type checkFunc func(dir string) (string, error)

func main() {
	useRubyVersionFile(rubyVersionChecker)
}

func useRubyVersionFile(checker checkFunc) {
	cwd, err := os.Getwd()
	if err != nil {
		os.Exit(1)
	}

	absCwd, err := filepath.Abs(cwd)
	if err != nil {
		os.Exit(1)
	}

	var userHome string
	if runtime.GOOS == `windows` {
		userHome = os.Getenv(`USERPROFILE`)
	} else {
		userHome = os.Getenv(`HOME`)
	}
	userHome, err = filepath.Abs(userHome)
	if err != nil {
		os.Exit(1)
	}
	if userHome == `` {
		os.Exit(1)
	}

	atRoot := false
	for !atRoot {
		// XXX scan stdlib to see if anything more robust than string compare
		if absCwd == userHome {
			absCwd = filepath.Dir(absCwd)
			continue
		}

		fmt.Printf("---> searching in %s\n", absCwd)
		checker(absCwd)
		absCwd = filepath.Dir(absCwd)
		err = os.Chdir(absCwd)
		if err != nil {
			os.Exit(1)
		}

		var path string
		if runtime.GOOS == `windows` {
			path = strings.Split(absCwd, `:`)[1]
		} else {
			path = absCwd
		}
		if strings.HasPrefix(path, string(os.PathSeparator)) &&
			strings.HasSuffix(path, string(os.PathSeparator)) {
			atRoot = true

			fmt.Printf("---> searching in %s\n", absCwd)
			checker(absCwd)
			err = os.Chdir(userHome)
			if err != nil {
				os.Exit(1)
			}

			fmt.Printf("---> searching in %s\n", userHome)
			checker(userHome)
		}
	}
}

func rubyVersionChecker(dir string) (version string, err error) {
	var path string
	if strings.HasSuffix(dir, string(os.PathSeparator)) {
		path = fmt.Sprintf("%s.ruby-version", dir)
	} else {
		path = fmt.Sprintf("%s%s.ruby-version", dir, string(os.PathSeparator))
	}

	fmt.Printf("--->   looking for %s\n", path)
	return
}

xxx

C:\Users\Jon\Documents\GoDev\sandbox>go run dirwalkup.go
---> searching in C:\Users\Jon\Documents\GoDev\sandbox
--->   looking for C:\Users\Jon\Documents\GoDev\sandbox\.ruby-version
---> searching in C:\Users\Jon\Documents\GoDev
--->   looking for C:\Users\Jon\Documents\GoDev\.ruby-version
---> searching in C:\Users\Jon\Documents
--->   looking for C:\Users\Jon\Documents\.ruby-version
---> searching in C:\Users\Jon                               <== suppress this check until end?
--->   looking for C:\Users\Jon\.ruby-version
---> searching in C:\Users
--->   looking for C:\Users\.ruby-version
---> searching in C:\
--->   looking for C:\.ruby-version
---> searching in C:\Users\Jon
--->   looking for C:\Users\Jon\.ruby-version

xxx_v2

C:\Users\Jon\Documents\GoDev\sandbox>go run dirwalkup.go
---> searching in C:\Users\Jon\Documents\GoDev\sandbox
--->   looking for C:\Users\Jon\Documents\GoDev\sandbox\.ruby-version
---> searching in C:\Users\Jon\Documents\GoDev
--->   looking for C:\Users\Jon\Documents\GoDev\.ruby-version
---> searching in C:\Users\Jon\Documents
--->   looking for C:\Users\Jon\Documents\.ruby-version
---> searching in C:\Users
--->   looking for C:\Users\.ruby-version
---> searching in C:\
--->   looking for C:\.ruby-version
---> searching in C:\Users\Jon
--->   looking for C:\Users\Jon\.ruby-version

@jonforums I think it should walk until HOME is reached (line 8)

@luislavena I also want to support dir structures like C:\Apps\projects\web\sinatra\trees-for-rent and E:\web-apps\invoicer in which the walk up will not pass through HOME.

I'll update the go code so that only HOME | USERPROFILE is checked as the final location after a complete walk up to / has already occurred. See what you think