feature add --include-lang option

main.go

@@ -63,6 +63,14 @@ func main() {
 	languages := GetDefinitionLanguages()
 	fileCache = make(map[string]struct{})
 
+	// setup option for include languages
+	IncludeLangs = make(map[string]struct{})
+	for _, lang := range strings.Split(opts.IncludeLang, ",") {
+		if _, ok := languages[lang]; ok {
+			IncludeLangs[lang] = struct{}{}
+		}
+	}
+
 	total := NewLanguage("TOTAL", "", "", "")
 	num, maxPathLen := getAllFiles(paths, languages)
 	headerLen := 28

option.go

@@ -7,6 +7,7 @@ type Options struct {
 	SortTag        string `long:"sort" default:"code" description:"sort based on a certain column"`
 	OutputType     string `long:"output-type" default:"default" description:"output type [values: default,cloc-xml,sloccount]"`
 	ExcludeExt     string `long:"exclude-ext" description:"exclude file name extensions (separated commas)"`
+	IncludeLang    string `long:"include-lang" description:"include language name (separated commas)"`
 	MatchDir       string `long:"match-d" description:"include dir name (regex)"`
 	NotMatchDir    string `long:"not-match-d" description:"exclude dir name (regex)"`
 	Debug          bool   `long:"debug" description:"dump debug log for developer"`
@@ -20,5 +21,6 @@ const OutputTypeSloccount string = "sloccount"
 
 var opts Options
 var ExcludeExts map[string]struct{}
+var IncludeLangs map[string]struct{}
 var reNotMatchDir *regexp.Regexp
 var reMatchDir *regexp.Regexp

utils.go

@@ -98,6 +98,12 @@ func getAllFiles(paths []string, languages map[string]*Language) (filenum, maxPa
 						return nil
 					}
 
+					if len(IncludeLangs) != 0 {
+						if _, ok = IncludeLangs[targetExt]; !ok {
+							return nil
+						}
+					}
+
 					ignore := checkMD5Sum(p)
 					if !opts.SkipUniqueness && ignore {
 						if opts.Debug {