add support for command line with frpc

src/frp/cmd/frpc/main.go

@@ -1,19 +1,79 @@
 package main
 
 import (
+	"fmt"
 	"os"
+	"strconv"
+	"strings"
 	"sync"
 
+	docopt "github.com/docopt/docopt-go"
+
 	"frp/models/client"
 	"frp/utils/log"
+	"frp/utils/version"
 )
 
+var (
+	configFile string = "./frpc.ini"
+)
+
+var usage string = `frpc is the client of frp
+
+Usage: 
+    frpc [-c config_file] [-L log_file] [--log-level=<log_level>] [--server-addr=<server_addr>]
+    frpc -h | --help | --version
+
+Options:
+    -c config_file              set config file
+    -L log_file                 set output log file, including console
+    --log-level=<log_level>     set log level: debug, info, warn, error
+    --server-addr=<server_addr> addr which frps is listening for, example: 0.0.0.0:7000
+    -h --help                   show this screen
+    --version                   show version
+`
+
 func main() {
-	err := client.LoadConf("./frpc.ini")
+	// the configures parsed from file will be replaced by those from command line if exist
+	args, err := docopt.Parse(usage, nil, true, version.Full(), false)
+
+	if args["-c"] != nil {
+		configFile = args["-c"].(string)
+	}
+	err = client.LoadConf(configFile)
 	if err != nil {
+		fmt.Println(err)
 		os.Exit(-1)
 	}
 
+	if args["-L"] != nil {
+		if args["-L"].(string) == "console" {
+			client.LogWay = "console"
+		} else {
+			client.LogWay = "file"
+			client.LogFile = args["-L"].(string)
+		}
+	}
+
+	if args["--log-level"] != nil {
+		client.LogLevel = args["--log-level"].(string)
+	}
+
+	if args["--server-addr"] != nil {
+		addr := strings.Split(args["--server-addr"].(string), ":")
+		if len(addr) != 2 {
+			fmt.Println("--server-addr format error: example 0.0.0.0:7000")
+			os.Exit(1)
+		}
+		serverPort, err := strconv.ParseInt(addr[1], 10, 64)
+		if err != nil {
+			fmt.Println("--server-addr format error, example 0.0.0.0:7000")
+			os.Exit(1)
+		}
+		client.ServerAddr = addr[0]
+		client.ServerPort = serverPort
+	}
+
 	log.InitLog(client.LogWay, client.LogFile, client.LogLevel)
 
 	// wait until all control goroutine exit