diff --git a/cmd/gogrep/main.go b/cmd/gogrep/main.go
index 8e75768..6a84ca6 100644
--- a/cmd/gogrep/main.go
+++ b/cmd/gogrep/main.go
@@ -2,57 +2,19 @@ package main
 
 import (
 	"fmt"
-	"io/fs"
 	"log"
-	"path/filepath"
 
 	cui "gitea.likemath.ru/alex/gogrep/internal/cui-args"
-	models "gitea.likemath.ru/alex/gogrep/internal/models"
 	processing "gitea.likemath.ru/alex/gogrep/internal/processing"
 )
 
-// ChannelBuffering is the size of file processing results queue
-const ChannelBuffering = 10
-
 func main() {
 	config, err := cui.ProcessConsoleArguments()
 	if err != nil {
 		log.Fatalf("Invalid config: %v\n", err)
 	}
-	processedChannel := make(chan models.FileMatchData, ChannelBuffering)
-	totalFiles := 0
-	err = filepath.Walk(".", func(path string, info fs.FileInfo, err error) error {
-		if err != nil {
-			fmt.Printf("prevent panic by handling failure accessing a path %q: %v\n", path, err)
-			return err
-		}
-		if config.PathPattern.FindString(path) == "" {
-			return nil
-		}
-		// if info.IsDir() && info.Name() == subDirToSkip {
-		// 	fmt.Printf("skipping a dir without errors: %+v \n", info.Name())
-		// 	return filepath.SkipDir
-		// }
-		if info.IsDir() {
-			return nil
-		}
-		go processing.ProcessSingleFile(config.TextPattern, path, processedChannel)
-		totalFiles++
-
-		return nil
-	})
-	for ; totalFiles > 0; totalFiles-- {
-		curProcessed := <-processedChannel
-		if len(curProcessed.Lines) == 0 {
-			continue
-		}
-		fmt.Printf("%s:\n", curProcessed.Path)
-		for i := 0; i < len(curProcessed.Lines); i++ {
-			fmt.Printf("%d:%s\n", curProcessed.LineIndexes[i], curProcessed.Lines[i])
-		}
-		fmt.Print("\n")
-	}
 
+	err = processing.DoGrepMain(config, ".")
 	if err != nil {
 		fmt.Printf("error walking the path %q: %v\n", config.PathPattern, err)
 		return
diff --git a/internal/processing/walk.go b/internal/processing/walk.go
new file mode 100644
index 0000000..5556a0e
--- /dev/null
+++ b/internal/processing/walk.go
@@ -0,0 +1,46 @@
+package processing
+
+import (
+	"fmt"
+	"io/fs"
+	"path/filepath"
+
+	models "gitea.likemath.ru/alex/gogrep/internal/models"
+)
+
+// ChannelBuffering is the size of file processing results queue
+const ChannelBuffering = 10
+
+// DoGrepMain performs full grep accorgind to config and root
+func DoGrepMain(config *models.GrepConfigInternal, root string) error {
+	processedChannel := make(chan models.FileMatchData, ChannelBuffering)
+	totalFiles := 0
+	err := filepath.Walk(root, func(path string, info fs.FileInfo, err error) error {
+		if err != nil {
+			fmt.Printf("prevent panic by handling failure accessing a path %q: %v\n", path, err)
+			return err
+		}
+		if config.PathPattern.FindString(path) == "" {
+			return nil
+		}
+		if info.IsDir() {
+			return nil
+		}
+		go ProcessSingleFile(config.TextPattern, path, processedChannel)
+		totalFiles++
+
+		return nil
+	})
+	for ; totalFiles > 0; totalFiles-- {
+		curProcessed := <-processedChannel
+		if len(curProcessed.Lines) == 0 {
+			continue
+		}
+		fmt.Printf("%s:\n", curProcessed.Path)
+		for i := 0; i < len(curProcessed.Lines); i++ {
+			fmt.Printf("%d:%s\n", curProcessed.LineIndexes[i], curProcessed.Lines[i])
+		}
+		fmt.Print("\n")
+	}
+	return err
+}