Small refactoring (for #108)

Author: alexpevzner

conf.go

@@ -10,7 +10,6 @@ package main
 
 import (
 	"errors"
-	"fmt"
 	"io"
 	"os"
 	"path/filepath"
@@ -60,23 +59,15 @@ var Conf = Configuration{
 
 // ConfLoad loads the program configuration
 func ConfLoad() error {
-	// Obtain path to executable directory
-	exepath, err := os.Executable()
-	if err != nil {
-		return fmt.Errorf("conf: %s", err)
-	}
-
-	exepath = filepath.Dir(exepath)
-
 	// Build list of configuration files
 	files := []string{
 		filepath.Join(PathConfDir, ConfFileName),
-		filepath.Join(exepath, ConfFileName),
+		filepath.Join(PathExecutableDir, ConfFileName),
 	}
 
 	// Load file by file
 	for _, file := range files {
-		err = confLoadInternal(file)
+		err := confLoadInternal(file)
 		if err != nil {
 			return err
 		}
@@ -86,12 +77,11 @@ func ConfLoad() error {
 	quirksDirs := []string{
 		PathLocalQuirksDir,
 		PathGlobalQuirksDir,
-		filepath.Join(exepath, "ipp-usb-quirks"),
+		filepath.Join(PathExecutableDir, "ipp-usb-quirks"),
 	}
 
-	if err == nil {
-		Conf.Quirks, err = LoadQuirksSet(quirksDirs...)
-	}
+	var err error
+	Conf.Quirks, err = LoadQuirksSet(quirksDirs...)
 
 	return err
 }

daemon.go

@@ -43,12 +43,6 @@ func CloseStdInOutErr() error {
 
 // Daemon runs ipp-usb program in background
 func Daemon() error {
-	// Obtain path to program's executable
-	exe, err := os.Executable()
-	if err != nil {
-		return err
-	}
-
 	// Create stdout/stderr pipes
 	rstdout, wstdout, err := os.Pipe()
 	if err != nil {
@@ -82,7 +76,7 @@ func Daemon() error {
 	}
 
 	// Start new process
-	proc, err := os.StartProcess(exe, args, attr)
+	proc, err := os.StartProcess(PathExecutableFile, args, attr)
 	if err != nil {
 		return err
 	}

main.go

@@ -176,6 +176,10 @@ func printStatus() {
 func main() {
 	var err error
 
+	// Initialize paths
+	err = PathsInit()
+	InitLog.Check(err)
+
 	// Parse arguments
 	params := parseArgv()
 

paths.go

@@ -9,6 +9,7 @@
 package main
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 )
@@ -38,6 +39,14 @@ var (
 
 	// Directory that contains per-device state files
 	PathDevStateDir = DefaultPathDevStateDir
+
+	// Path to the program's executable file.
+	// Initialized by PathInit()
+	PathExecutableFile string
+
+	// Path to the directory that contains the executable file.
+	// Initialized by PathInit()
+	PathExecutableDir string
 )
 
 // Default paths:
@@ -77,6 +86,22 @@ const (
 	DefaultPathMainLogFile = DefaultPathLogDir + "/main.log"
 )
 
+// PathsInit initializes paths handling.
+func PathsInit() error {
+	// Initialize PathExecutableFile and PathExecutableDir
+	var err error
+	PathExecutableFile, err = os.Executable()
+	if err != nil {
+		err = fmt.Errorf(
+			"Error getting path to the executable file: %s", err)
+		return err
+	}
+
+	PathExecutableDir = filepath.Dir(PathExecutableFile)
+
+	return nil
+}
+
 // MakeDirectory creates a directory, specified by the path,
 // along with any necessary parents.
 //