Back then I forgot it is not C, just compare with full strings in switch.

Makefile

@@ -8,7 +8,7 @@ endif
 DESTDIR:=
 PREFIX:=/usr/local
 
-VERSION=0.1.1
+VERSION=0.1.2
 
 FLAGS:=-buildmode=pie -modcacherw -mod=readonly -trimpath
 LDFLAGS:= -ldflags "-s -w -X main.programVersion=${VERSION}"

build/PKGBUILD

@@ -1,6 +1,6 @@
 # Maintainer: Alexander "Arav" Andreev <me@arav.su>
 pkgname=mccl
-pkgver=0.1.1
+pkgver=0.1.2
 pkgrel=1
 pkgdesc="Console Minecraft launcher"
 arch=('i686' 'x86_64' 'arm' 'armv6h' 'armv7h' 'aarch64')

cmd/mccl/main.go

@@ -31,7 +31,7 @@ func main() {
 
 	if len(os.Args) < 2 {
 		usage()
-		os.Exit(0)
+		os.Exit(1)
 	}
 
 	var cmd commands.Command
@@ -90,8 +90,8 @@ func usage() {
 		"  \033[1mlist|l\033[0m directory\n"+
 		"    List all installed versions in directory\n"+
 		"Explanation of arguments and options for commands:\n"+
-		"    version    minecraft's version \n"+
-		"    directory  a path to where Minecraft will be installed\n"+
+		"    version    version of a game (name of a dir inside versions dir)\n"+
+		"    directory  a path to where Minecraft will be installed / or will be runned from\n"+
 		"    -u,--username username\n"+
 		"               player's username (Anonymous by default)\n"+
 		"    -U,--uuid UUID\n"+
@@ -101,7 +101,7 @@ func usage() {
 		"    --profile\n"+
 		"               load/save username, UUID, and -Xmx from/to a file.\n"+
 		"               Once saved, you can ommit -u,-U and --java-Xmx,\n"+
-		"               since they are stored in", mcclprofile.ProfileFileName)
+		"               since they will be stored in", mcclprofile.ProfileFileName)
 }
 
 type arguments struct {
@@ -131,101 +131,49 @@ func parseArguments(args []string) (parsed arguments, err error) {
 	parsed.Username = "Anonymous"
 	parsed.Directory = "."
 	parsed.Uuid = "00000000-0000-0000-0000-000000000000"
+
 	for i := 0; i < len(args); i++ {
-		if len(args[i]) > 2 && args[i][0] == '-' && args[i][1] == '-' {
-			switch args[i][2:] {
-			case "version":
-				parsed.ShowVersion = true
-			case "help":
-				parsed.ShowHelp = true
-			case "demand-press-enter":
-				parsed.DemandPressEnter = true
-			case "username":
-				if len(args) == i+1 || args[i+1][0] == '-' {
-					err = errNoOptArg{ArgName: args[i]}
-					return
-				}
-				parsed.Username = args[i+1]
-				i++
-			case "uuid":
-				if len(args) == i+1 || args[i+1][0] == '-' {
-					err = errNoOptArg{ArgName: args[i]}
-					return
-				}
-				parsed.Uuid = args[i+1]
-				i++
-			case "java-Xmx":
-				if len(args) == i+1 || args[i+1][0] == '-' {
-					err = errNoOptArg{ArgName: args[i]}
-					return
-				}
-				parsed.JavaXmx = args[i+1]
-				i++
-			case "profile":
-				parsed.UseProfile = true
-			default:
-				err = fmt.Errorf("an unknown option %s was provided", args[i])
+		switch args[i] {
+		case "-v":
+			fallthrough
+		case "--version":
+			parsed.ShowVersion = true
+		case "-h":
+			fallthrough
+		case "--help":
+			parsed.ShowHelp = true
+		case "--demand-press-enter":
+			parsed.DemandPressEnter = true
+		case "-u":
+			fallthrough
+		case "--username":
+			if len(args) == i+1 || args[i+1][0] == '-' {
+				err = errNoOptArg{ArgName: args[i]}
 				return
 			}
-		} else if args[i][0] == '-' && len(args[i]) > 1 {
-			for _, option := range args[i][1:] {
-				switch option {
-				case 'v':
-					parsed.ShowVersion = true
-				case 'h':
-					parsed.ShowHelp = true
-				case 'u':
-					if len(args) == i+1 || args[i+1][0] == '-' {
-						err = errNoOptArg{ArgName: args[i]}
-						return
-					}
-					parsed.Username = args[i+1]
-					i++
-				case 'U':
-					if len(args) == i+1 || args[i+1][0] == '-' {
-						err = errNoOptArg{ArgName: args[i]}
-						return
-					}
-					parsed.Uuid = args[i+1]
-					i++
-				default:
-					err = fmt.Errorf("an unknown option %c was provided", option)
-					return
-				}
-			}
-		} else {
-			if parsed.Command != "" {
-				err = fmt.Errorf("only one command should present")
+			parsed.Username = args[i+1]
+			i++
+		case "-U":
+			fallthrough
+		case "--uuid":
+			if len(args) == i+1 || args[i+1][0] == '-' {
+				err = errNoOptArg{ArgName: args[i]}
 				return
 			}
-			switch parsed.Command = args[i]; parsed.Command {
-			case "i":
-				fallthrough
-			case "install":
-				fallthrough
-			case "r":
-				fallthrough
-			case "run":
-				if len(args) <= i+3 || args[i+1][0] == '-' || args[i+2][0] == '-' {
-					err = fmt.Errorf("not enough arguments was provided")
-					return
-				}
-				parsed.GameVersion = args[i+1]
-				parsed.Directory = args[i+2]
-				i += 2
-			case "l":
-				fallthrough
-			case "list":
-				if len(args) <= i+2 || args[i+1][0] == '-' {
-					err = fmt.Errorf("not enough arguments was provided")
-					return
-				}
-				parsed.Directory = args[i+1]
-				i++
-			default:
-				err = fmt.Errorf("an unknown command %s was provided", parsed.Command)
+			parsed.Uuid = args[i+1]
+			i++
+		case "--java-Xmx":
+			if len(args) == i+1 || args[i+1][0] == '-' {
+				err = errNoOptArg{ArgName: args[i]}
 				return
 			}
+			parsed.JavaXmx = args[i+1]
+			i++
+		case "--profile":
+			parsed.UseProfile = true
+		default:
+			err = fmt.Errorf("an unknown option %s was provided", args[i])
+			return
 		}
 	}
 	return