change(config): check if current binary path is writeable, use altern…

…ative if not

when binary path is not writeable, .config/crop will be used within user home directory

cmd/root.go

@@ -20,7 +20,7 @@ import (
 var (
 	// Global flags
 	flagLogLevel     = 0
-	flagConfigFolder = pathutils.GetCurrentBinaryPath()
+	flagConfigFolder = pathutils.GetDefaultConfigPath()
 	flagConfigFile   = "config.yaml"
 	flagCachePath    = "cache"
 	flagLogFile      = "activity.log"
@@ -55,6 +55,7 @@ func init() {
 	rootCmd.PersistentFlags().StringVarP(&flagConfigFile, "config", "c", flagConfigFile, "Config file")
 	rootCmd.PersistentFlags().StringVarP(&flagCachePath, "cache", "d", flagCachePath, "Cache path")
 	rootCmd.PersistentFlags().StringVarP(&flagLogFile, "log", "l", flagLogFile, "Log file")
+	rootCmd.PersistentFlags().StringVarP(&flagLockFile, "lock", "f", flagLockFile, "Lock file")
 	rootCmd.PersistentFlags().CountVarP(&flagLogLevel, "verbose", "v", "Verbose level")
 
 	rootCmd.PersistentFlags().BoolVar(&flagDryRun, "dry-run", false, "Dry run mode")
@@ -71,8 +72,9 @@ func initCore(showAppInfo bool) {
 	if !rootCmd.PersistentFlags().Changed("log") {
 		flagLogFile = filepath.Join(flagConfigFolder, flagLogFile)
 	}
-
-	flagLockFile = filepath.Join(flagConfigFolder, flagLockFile)
+	if !rootCmd.PersistentFlags().Changed("lock") {
+		flagLockFile = filepath.Join(flagConfigFolder, flagLockFile)
+	}
 
 	// Init Logging
 	if err := logger.Init(flagLogLevel, flagLogFile); err != nil {

go.mod

@@ -40,7 +40,7 @@ require (
 	golang.org/x/crypto v0.0.0-20200604202706-70a84ac30bf9 // indirect
 	golang.org/x/net v0.0.0-20200602114024-627f9648deb9 // indirect
 	golang.org/x/oauth2 v0.0.0-20200107190931-bf48bf16ab8d // indirect
-	golang.org/x/sys v0.0.0-20200610111108-226ff32320da // indirect
+	golang.org/x/sys v0.0.0-20200610111108-226ff32320da
 	google.golang.org/appengine v1.6.6 // indirect
 	google.golang.org/protobuf v1.24.0 // indirect
 	gopkg.in/ini.v1 v1.57.0 // indirect

pathutils/file.go

@@ -1,19 +1,75 @@
 package pathutils
 
 import (
+	"github.com/pkg/errors"
+	"golang.org/x/sys/unix"
 	"os"
 	"path/filepath"
+	"runtime"
 )
 
 /* Public */
 
 func GetCurrentBinaryPath() string {
+	// get current binary path
 	dir, err := filepath.Abs(filepath.Dir(os.Args[0]))
 	if err != nil {
 		// get current working dir
 		if dir, err = os.Getwd(); err != nil {
-			os.Exit(1)
+			panic("failed to determine current binary location")
 		}
 	}
+
 	return dir
 }
+
+func GetDefaultConfigPath() string {
+	// get binary path
+	bp := GetCurrentBinaryPath()
+	if dirIsWriteable(bp) == nil {
+		return bp
+	}
+
+	// binary path is not write-able, use alternative path
+	uhp, err := os.UserHomeDir()
+	if err != nil {
+		panic("failed to determine current user home directory")
+	}
+
+	// set crop path inside user home dir
+	chp := filepath.Join(uhp, ".config", "crop")
+	if _, err := os.Stat(chp); os.IsNotExist(err) {
+		if e := os.MkdirAll(chp, os.ModePerm); e != nil {
+			panic("failed to create crop config directory")
+		}
+	}
+
+	return chp
+}
+
+/* Private */
+
+func dirIsWriteable(dir string) error {
+	// credits: https://stackoverflow.com/questions/20026320/how-to-tell-if-folder-exists-and-is-writable
+	var err error
+
+	if runtime.GOOS != "windows" {
+		err = unix.Access(dir, unix.W_OK)
+	} else {
+		f, e := os.Stat(dir)
+		if e != nil {
+			return e
+		}
+
+		switch {
+		case !f.IsDir():
+			err = errors.New("dir is not a directory")
+		case f.Mode().Perm()&(1<<(uint(7))) == 0:
+			err = errors.New("dir is not writeable")
+		default:
+			break
+		}
+	}
+
+	return err
+}