Improved CLI

src/cli/Build.go

@@ -2,6 +2,7 @@ package cli
 
 import (
 	"fmt"
+	"os"
 	"strings"
 
 	"git.akyoto.dev/cli/q/src/build"
@@ -11,12 +12,12 @@ import (
 // Build builds an executable.
 func Build(args []string) int {
 	b := build.New()
-	writeExecutable := true
+	dry := false
 
 	for i := 0; i < len(args); i++ {
 		switch args[i] {
 		case "--dry":
-			writeExecutable = false
+			dry = true
 
 		case "--verbose", "-v":
 			config.Verbose = true
@@ -38,7 +39,7 @@ func Build(args []string) int {
 	result, err := b.Run()
 
 	if err != nil {
-		fmt.Println(err)
+		fmt.Fprintln(os.Stderr, err)
 		return 1
 	}
 
@@ -48,7 +49,7 @@ func Build(args []string) int {
 		}
 	}
 
-	if !writeExecutable {
+	if dry {
 		return 0
 	}
 
@@ -57,7 +58,7 @@ func Build(args []string) int {
 	err = build.Write(path, code, data)
 
 	if err != nil {
-		fmt.Println(err)
+		fmt.Fprintln(os.Stderr, err)
 		return 1
 	}
 

src/cli/Help.go

@@ -1,12 +1,16 @@
 package cli
 
-import "fmt"
+import (
+	"fmt"
+	"io"
+)
 
 // Help shows the command line argument usage.
-func Help(args []string) int {
-	fmt.Println("Usage: q [command] [options]")
-	fmt.Println("")
-	fmt.Println("    build [directory] [file]")
-	fmt.Println("    system")
-	return 2
+func Help(w io.Writer, code int) int {
+	fmt.Fprintln(w, "Usage: q [command] [options]")
+	fmt.Fprintln(w, "")
+	fmt.Fprintln(w, "    build [directory] [file]")
+	fmt.Fprintln(w, "    help")
+	fmt.Fprintln(w, "    system")
+	return code
 }

src/cli/Main.go

@@ -1,11 +1,13 @@
 package cli
 
+import "os"
+
 // Main is the entry point for the CLI frontend.
 // It returns the exit code of the compiler.
 // We never call os.Exit directly here because it's bad for testing.
 func Main(args []string) int {
 	if len(args) == 0 {
-		return Help(nil)
+		return Help(os.Stderr, 2)
 	}
 
 	switch args[0] {
@@ -15,7 +17,10 @@ func Main(args []string) int {
 	case "system":
 		return System(args[1:])
 
+	case "help":
+		return Help(os.Stdout, 0)
+
 	default:
-		return Help(args[1:])
+		return Help(os.Stderr, 2)
 	}
 }