adds safeguards to avoid using '~' directory

if homedir can not be guessed, we have to exit.
previously, '~' was used but this directory is not expanded so we can not use this.

cmd/root.go

@@ -90,13 +90,35 @@ selected.`,
 		},
 	}
 
+	// If we can not guess those directories, we have to bailout
+	dbin, err := app.GetDefaultBinDir()
+	if err != nil {
+		err = fmt.Errorf("unable to guess binaries directory: %v", err)
+		panic(err)
+	}
+	dlink, err := app.GetDefaultLinkDir()
+	if err != nil {
+		err = fmt.Errorf("unable to guess link directory: %v", err)
+		panic(err)
+	}
+	dcache, err := app.GetDefaultCacheDir()
+	if err != nil {
+		err = fmt.Errorf("unable to guess cache directory: %v", err)
+		panic(err)
+	}
+	dconf, err := app.GetDefaultConfDir()
+	if err != nil {
+		err = fmt.Errorf("unable to guess conf directory: %v", err)
+		panic(err)
+	}
+
 	rootCmd.PersistentFlags().BoolVarP(&verbose, "verbose", "v", false, "verbose operation [BINENV_VERBOSE]")
 	rootCmd.PersistentFlags().BoolVarP(&global, "global", "g", false, "global mode [BINENV_GLOBAL]")
 
-	rootCmd.PersistentFlags().StringVarP(&bindir, "bindir", "B", app.GetDefaultBinDir(), "binaries directory [BINENV_BINDIR]")
-	rootCmd.PersistentFlags().StringVarP(&linkdir, "linkdir", "L", app.GetDefaultLinkDir(), "link directory [BINENV_LINKDIR]")
-	rootCmd.PersistentFlags().StringVarP(&cachedir, "cachedir", "K", app.GetDefaultCacheDir(), "cache directory [BINENV_CACHEDIR]")
-	rootCmd.PersistentFlags().StringVarP(&confdir, "confdir", "C", app.GetDefaultConfDir(), "distributions configuration directory [BINENV_CONFDIR]")
+	rootCmd.PersistentFlags().StringVarP(&bindir, "bindir", "B", dbin, "binaries directory [BINENV_BINDIR]")
+	rootCmd.PersistentFlags().StringVarP(&linkdir, "linkdir", "L", dlink, "link directory [BINENV_LINKDIR]")
+	rootCmd.PersistentFlags().StringVarP(&cachedir, "cachedir", "K", dcache, "cache directory [BINENV_CACHEDIR]")
+	rootCmd.PersistentFlags().StringVarP(&confdir, "confdir", "C", dconf, "distributions configuration directory [BINENV_CONFDIR]")
 
 	rootCmd.AddCommand(
 		completionCmd(),

internal/app/utils.go

@@ -10,51 +10,51 @@ import (
 )
 
 // GetDefaultBinDir returns the bin directory in usermode
-func GetDefaultBinDir() string {
+func GetDefaultBinDir() (string, error) {
 	d, err := homedir.Dir()
 	if err != nil {
-		d = "~"
+		return "", err
 	}
 	d += "/.binenv/"
 
-	return d
+	return d, nil
 }
 
 // GetDefaultLinkDir returns the bin directory in usermode
-func GetDefaultLinkDir() string {
+func GetDefaultLinkDir() (string, error) {
 	return GetDefaultBinDir()
 }
 
 // GetDefaultConfDir returns the config directory in usermode
-func GetDefaultConfDir() string {
+func GetDefaultConfDir() (string, error) {
 	var err error
 
-	dir := os.Getenv("XDG_CONFIG_HOME")
-	if dir == "" {
-		dir, err = homedir.Dir()
+	d := os.Getenv("XDG_CONFIG_HOME")
+	if d == "" {
+		d, err = homedir.Dir()
 		if err != nil {
-			dir = "~"
+			return "", err
 		}
-		dir += "/.config/binenv"
+		d += "/.config/binenv"
 	}
 
-	return dir
+	return d, nil
 }
 
 // GetDefaultCacheDir returns the cache directory in usermode
-func GetDefaultCacheDir() string {
+func GetDefaultCacheDir() (string, error) {
 	var err error
 
-	dir := os.Getenv("XDG_CACHE_HOME")
-	if dir == "" {
-		dir, err = homedir.Dir()
+	d := os.Getenv("XDG_CACHE_HOME")
+	if d == "" {
+		d, err = homedir.Dir()
 		if err != nil {
-			dir = "~"
+			return "", err
 		}
-		dir += "/.cache/binenv"
+		d += "/.cache/binenv"
 	}
 
-	return dir
+	return d, nil
 }
 
 func stringInSlice(st string, sl []string) bool {