save access token

client.go

@@ -37,6 +37,7 @@ func newMatrixClient(config *botConfig) *mautrix.Client {
 		}
 		config.Token = loginRes.AccessToken
 		log.Println("Login succesful, saving access_token to config file")
+		writeConfig(config)
 	} else {
 		log.Println("skipping login since token provided")
 	}

config.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"io/ioutil"
+	"log"
+	"os"
 
 	"gopkg.in/yaml.v2"
 )
@@ -14,6 +16,7 @@ type botConfig struct {
 	Password   string `yaml:"password"`
 	Statefile  string `yaml:"statefile"`
 	Token      string `yaml:"token"`
+	filename   string
 }
 
 func loadConfig(filename string) *botConfig {
@@ -27,5 +30,21 @@ func loadConfig(filename string) *botConfig {
 	if err != nil {
 		panic(err)
 	}
+	cnf.filename = filename
 	return cnf
 }
+
+func writeConfig(cnf *botConfig) {
+	file, err := os.OpenFile(cnf.filename, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
+	if err != nil {
+		log.Fatalf("error opening/creating file: %v", err)
+	}
+	defer file.Close()
+
+	enc := yaml.NewEncoder(file)
+
+	err = enc.Encode(cnf)
+	if err != nil {
+		log.Fatalf("error encoding: %v", err)
+	}
+}