Do not repeat code whenever possible

Signed-off-by: Shin'ya Minazuki <shinyoukai@laidback.moe>

README.md

@@ -2,6 +2,7 @@
 [Yarn.social](https://yarn.social) client where each task (except for logout) is handled by a separate program.
 
 ## Current status
+* [ ] Follow/Unfollow
 * [X] Login
 * [X] Posting
 * [ ] Timeline

cmd/mikuru-login/main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"fmt"
+	"log"
 	"os"
 	"strings"
 	"syscall"
@@ -17,24 +18,22 @@ var (
 )
 
 func init() {
-	config, err := os.UserConfigDir()
-	if err != nil {
-		fmt.Println("Unable to obtain user's configuration directory")
-		os.Exit(1)
-	}
-	configPath := config + "/mikuru.ini"
-	mikuru.Parse(configPath)
+	mikuru.ConfInit()
 }
 
 func main() {
 	cli, err := client.NewClient(client.WithURI(mikuru.Config.Host))
 	if err != nil {
-		fmt.Printf("%s", err)
-		fmt.Println("Error creating client")
-		os.Exit(1)
+		log.Println("Unable to create client")
+		log.Fatal(err)
 	}
+	
+	fmt.Println("Welcome to Mikuru!")
+	fmt.Printf("%s\n", mikuru.PrintVersion())
+
 	signin(cli)
 }
+
 func signin(cli *client.Client) {
 	fmt.Printf("Username: ")
 	fmt.Scanln(&username)

cmd/mikuru-post/main.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"log"
-	"os"
 
 	"git.laidback.moe/shinyoukai/mikuru"
 	"go.yarn.social/client"
@@ -10,13 +9,7 @@ import (
 )
 
 func init() {
-	config, err := os.UserConfigDir()
-	if err != nil {
-		log.Fatalf("%s\n")
-	}
-
-	configPath := config + "/mikuru.ini"
-	mikuru.Parse(configPath)
+	mikuru.ConfInit()
 }
 
 func main() {

config.go

@@ -1,6 +1,8 @@
 package mikuru
 
 import (
+	"log"
+	"os"
 	"gopkg.in/ini.v1"
 )
 
@@ -9,6 +11,16 @@ var Config struct {
 	Token string
 }
 
+func ConfInit() {
+	config, err := os.UserConfigDir()
+        if err != nil {
+                log.Println("Unable to obtain user's configuration directory")
+                log.Fatal(err)
+        }
+        configPath := config + "/mikuru.ini"
+        Parse(configPath)
+}
+
 func Parse(file string) error {
 	cfg, err := ini.Load(file)
 	if err != nil {