add charset flag

README.md

@@ -17,6 +17,7 @@ Optionally, `ep` can:
 * dry-run (`-d` flag): output to stdout instead of replacing values inline
 * strict (`-s` flag): refuse to fallback to default values
 * verbose (`-v` flag): be verbose about it's operations
+* charset (`-c` flag): specify a custom charset to replace variables. Example: `/usr/local/bin/ep -c iso8859-1 *.conf`
 
 `ep` can also `exec()` another command by passing
 

bin/ep.go

@@ -9,6 +9,7 @@ import (
 	"github.com/kreuzwerker/envplate"
 	"github.com/spf13/cobra"
 	"github.com/yawn/doubledash"
+	_ "github.com/paulrosania/go-charset/data"
 )
 
 var (
@@ -27,6 +28,7 @@ func main() {
 		dryRun  *bool
 		strict  *bool
 		verbose *bool
+		charset *string
 	)
 
 	root := &cobra.Command{
@@ -41,6 +43,7 @@ func main() {
 				Backup: *backup,
 				DryRun: *dryRun,
 				Strict: *strict,
+				Charset: *charset,
 			}
 
 			if err := h.Apply(args); err != nil {
@@ -67,6 +70,7 @@ func main() {
 	dryRun = root.Flags().BoolP("dry-run", "d", false, "Dry-run - output templates to stdout instead of inline replacement")
 	strict = root.Flags().BoolP("strict", "s", false, "Strict-mode - fail when falling back on defaults")
 	verbose = root.Flags().BoolP("verbose", "v", false, "Verbose logging")
+	charset = root.Flags().StringP("charset", "c", "", "Output charset")
 
 	if err := root.Execute(); err != nil {
 		log.Fatalf("Failed to start the application: %v", err)

envplate.go

@@ -5,19 +5,23 @@ import (
 	"os"
 	"path/filepath"
 	"regexp"
+	"fmt"
+	"bytes"
 
 	"github.com/yawn/envmap"
-)
+	"github.com/paulrosania/go-charset/charset"
+) 
 
 const (
 	noDefaultDefined    = ""
 	notAnEscapeSequence = ""
 )
 
 type Handler struct {
-	Backup bool
-	DryRun bool
-	Strict bool
+	Backup  bool
+	DryRun  bool
+	Strict  bool
+	Charset string
 }
 
 var exp = regexp.MustCompile(`(\\*)\$\{(.+?)(?:(\:\-)(.*?))?\}`)
@@ -62,7 +66,7 @@ func (h *Handler) parse(file string) error {
 
 	env := envmap.Import()
 	content, err := ioutil.ReadFile(file)
-
+	
 	if err != nil {
 		return Log(ERROR, "Cannot open %s: %v", file, err)
 	}
@@ -86,8 +90,12 @@ func (h *Handler) parse(file string) error {
 				errors = append(errors, Log(ERROR, "Tried to escape '%s', but was no escape sequence", content))
 			}
 
-			return escaped
-
+			encodedValue, err := convertToCharset(escaped, h.Charset)
+			if err != nil {
+				errors = append(errors, Log(ERROR, "Tried to convert string '%s' to charset '%s'  but an error ocourred: %v", encodedValue, h.Charset, err))
+				return value
+			}
+			return encodedValue
 		}
 
 		if !keyDefined {
@@ -112,9 +120,12 @@ func (h *Handler) parse(file string) error {
 		if len(esc) > 0 {
 			value = esc[:len(esc)/2] + value
 		}
-
-		return value
-
+		encodedValue, err := convertToCharset(value, h.Charset)
+		if err != nil {
+			errors = append(errors, Log(ERROR, "Tried to convert string '%s' to charset '%s'  but an error ocourred: %v", encodedValue, h.Charset, err))
+			return value
+		}
+		return encodedValue
 	})
 
 	if h.DryRun {
@@ -131,25 +142,45 @@ func (h *Handler) parse(file string) error {
 			}
 
 		}
-
-		mode, err := filemode(file)
-
-		if err != nil {
-			return err
-		}
-
-		if err := ioutil.WriteFile(file, []byte(parsed), mode); err != nil {
+		if err := saveFile(file, parsed, h.Charset); err != nil {
 			return err
 		}
-
 	}
 
 	if len(errors) > 0 {
 		return errors[0]
 	}
 
 	return nil
+}
+
+
+func saveFile(file string, parsed string, cs string) error {
+	mode, err := filemode(file)
+	if err != nil {
+		return err
+	}
 
+	if err := ioutil.WriteFile(file, []byte(parsed), mode); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func convertToCharset(data string, charSet string) (string, error) {
+	if charSet == "" {
+		return data, nil
+	}
+
+	buf := new(bytes.Buffer)
+	w, err := charset.NewWriter(charSet, buf)
+	if err != nil {				
+	    return "", err
+	}
+	fmt.Fprintf(w, data)
+	w.Close()
+	return string(buf.Bytes()), nil
 }
 
 func capture(s string) (esc, key, sep, def string) {