hclfmt: initial skeleton

hclfmt.go

@@ -0,0 +1,101 @@
+package main
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"go/scanner"
+	"io"
+	"os"
+	"path/filepath"
+	"runtime/pprof"
+	"strings"
+)
+
+func main() {
+	if err := realMain(); err != nil {
+		fmt.Fprintln(os.Stderr, err.Error())
+		os.Exit(1)
+	}
+}
+
+func realMain() error {
+	var (
+		write = flag.Bool("w", false, "write result to (source) file instead of stdout")
+
+		// debugging
+		cpuprofile = flag.String("cpuprofile", "", "write cpu profile to this file")
+	)
+
+	flag.Usage = usage
+	flag.Parse()
+
+	if *cpuprofile != "" {
+		f, err := os.Create(*cpuprofile)
+		if err != nil {
+			return fmt.Errorf("creating cpu profile: %s\n", err)
+		}
+		defer f.Close()
+		pprof.StartCPUProfile(f)
+		defer pprof.StopCPUProfile()
+	}
+
+	if flag.NArg() == 0 {
+		if *write {
+			return errors.New("error: cannot use -w with standard input")
+		}
+
+		return processFile("<standard input>", os.Stdin, os.Stdout, true)
+	}
+
+	for i := 0; i < flag.NArg(); i++ {
+		path := flag.Arg(i)
+		switch dir, err := os.Stat(path); {
+		case err != nil:
+			report(err)
+		case dir.IsDir():
+			walkDir(path)
+		default:
+			if err := processFile(path, nil, os.Stdout, false); err != nil {
+				report(err)
+			}
+		}
+	}
+
+	return nil
+}
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: hclfmt [flags] [path ...]\n")
+	flag.PrintDefaults()
+	os.Exit(2)
+}
+
+func isGoFile(f os.FileInfo) bool {
+	// ignore non-Go files
+	name := f.Name()
+	return !f.IsDir() && !strings.HasPrefix(name, ".") && strings.HasSuffix(name, ".go")
+}
+
+func report(err error) {
+	scanner.PrintError(os.Stderr, err)
+}
+
+func walkDir(path string) {
+	filepath.Walk(path, visitFile)
+}
+
+func visitFile(path string, f os.FileInfo, err error) error {
+	if err == nil && isGoFile(f) {
+		err = processFile(path, nil, os.Stdout, false)
+	}
+	if err != nil {
+		report(err)
+	}
+	return nil
+}
+
+// If in == nil, the source is the contents of the file with the given filename.
+func processFile(filename string, in io.Reader, out io.Writer, stdin bool) error {
+	return errors.New("not imlemented yet")
+}