diff --git a/Makefile b/Makefile
index f64adc4..f2a12fc 100644
--- a/Makefile
+++ b/Makefile
@@ -30,4 +30,4 @@ lint:
 	golint ./shared/ ./tests/ ./cmd/...
 
 clean:
-	rm -f data/hello data/hello.bc [td]*/.helloworld.c.o [td]*/.helloworld.c.o.bc
+	rm -f data/*hello data/*.bc [td]*/.*.c.o [td]*/*.o [td]*/.*.c.o.bc data/*.notanextensionthatwerecognize
diff --git a/shared/filetypes.go b/shared/filetypes.go
index 63e582e..ef9167e 100644
--- a/shared/filetypes.go
+++ b/shared/filetypes.go
@@ -141,12 +141,15 @@ func machoType2BinaryType(mt macho.Type) (bt BinaryType) {
 // IsPlainFile returns true if the file is stat-able (i.e. exists etc), and is not a directory, else it returns false.
 func IsPlainFile(objectFile string) (ok bool) {
 	info, err := os.Stat(objectFile)
-	if os.IsNotExist(err) || info.IsDir() {
+	if os.IsNotExist(err) {
 		return
 	}
 	if err != nil {
 		return
 	}
+	if info.IsDir() {
+		return
+	}
 	ok = true
 	return
 }
diff --git a/tests/entry_test.go b/tests/entry_test.go
index 41cf5e1..0abd9c3 100644
--- a/tests/entry_test.go
+++ b/tests/entry_test.go
@@ -7,19 +7,23 @@ import (
 	"testing"
 )
 
+const (
+	DEBUG bool = false
+)
+
 func Test_basic_functionality(t *testing.T) {
 	args := []string{"../data/helloworld.c", "-o", "../data/hello"}
 	exitCode := shared.Compile(args, "clang")
 	if exitCode != 0 {
 		t.Errorf("Compile of %v returned %v\n", args, exitCode)
-	} else {
+	} else if DEBUG {
 		fmt.Println("Compiled OK")
 	}
 	args = []string{"get-bc", "-v", "../data/hello"}
 	exitCode = shared.Extract(args)
 	if exitCode != 0 {
 		t.Errorf("Extraction of %v returned %v\n", args, exitCode)
-	} else {
+	} else if DEBUG {
 		fmt.Println("Extraction OK")
 	}
 }
@@ -30,27 +34,27 @@ func Test_more_functionality(t *testing.T) {
 	exitCode := shared.Compile(args, "clang")
 	if exitCode != 0 {
 		t.Errorf("Compile of %v returned %v\n", args, exitCode)
-	} else {
+	} else if DEBUG {
 		fmt.Println("Compiled OK")
 	}
 	ok, err := shared.IsObjectFileForOS(objectFile, runtime.GOOS)
 	if !ok {
 		t.Errorf("isObjectFileForOS(%v, %v) = %v (err = %v)\n", objectFile, runtime.GOOS, ok, err)
-	} else {
+	} else if DEBUG {
 		fmt.Printf("isObjectFileForOS(%v, %v) = %v\n", objectFile, runtime.GOOS, ok)
 	}
 	args = []string{objectFile, "-o", "../data/bhello"}
 	exitCode = shared.Compile(args, "clang")
 	if exitCode != 0 {
 		t.Errorf("Compile of %v returned %v\n", args, exitCode)
-	} else {
+	} else if DEBUG {
 		fmt.Println("Compiled OK")
 	}
 	args = []string{"get-bc", "-v", "../data/bhello"}
 	exitCode = shared.Extract(args)
 	if exitCode != 0 {
 		t.Errorf("Extraction of %v returned %v\n", args, exitCode)
-	} else {
+	} else if DEBUG {
 		fmt.Println("Extraction OK")
 	}
 }
@@ -64,39 +68,39 @@ func Test_obscure_functionality(t *testing.T) {
 	exitCode := shared.Compile(args, "clang")
 	if exitCode != 0 {
 		t.Errorf("Compile of %v returned %v\n", args, exitCode)
-	} else {
+	} else if DEBUG {
 		fmt.Println("Compiled OK")
 	}
 	ok, err := shared.IsObjectFileForOS(sourceFile, opSys)
 	if ok {
 		t.Errorf("isObjectFileForOS(%v, %v) = %v\n", sourceFile, opSys, ok)
-	} else {
+	} else if DEBUG {
 		fmt.Printf("isObjectFileForOS(%v, %v) = %v (err = %v)\n", sourceFile, opSys, ok, err)
 	}
 	ok, err = shared.IsObjectFileForOS(objectFile, opSys)
 	if !ok {
 		t.Errorf("isObjectFileForOS(%v, %v) = %v (err = %v)\n", objectFile, opSys, ok, err)
-	} else {
+	} else if DEBUG {
 		fmt.Printf("isObjectFileForOS(%v, %v) = %v\n", objectFile, opSys, ok)
 	}
 	args = []string{objectFile, "-o", exeFile}
 	exitCode = shared.Compile(args, "clang")
 	if exitCode != 0 {
 		t.Errorf("Compile of %v returned %v\n", args, exitCode)
-	} else {
+	} else if DEBUG {
 		fmt.Println("Compiled OK")
 	}
 	ok, err = shared.IsObjectFileForOS(exeFile, opSys)
 	if ok {
 		t.Errorf("isObjectFileForOS(%v, %v) = %v\n", exeFile, opSys, ok)
-	} else {
+	} else if DEBUG {
 		fmt.Printf("isObjectFileForOS(%v, %v) = %v (err = %v)\n", exeFile, opSys, ok, err)
 	}
 	args = []string{"get-bc", "-v", exeFile}
 	exitCode = shared.Extract(args)
 	if exitCode != 0 {
 		t.Errorf("Extraction of %v returned %v\n", args, exitCode)
-	} else {
+	} else if DEBUG {
 		fmt.Println("Extraction OK")
 	}
 }
@@ -107,40 +111,79 @@ func Test_file_type(t *testing.T) {
 	sourceFile := "../data/helloworld.c"
 	objectFile := "../data/bhello.notanextensionthatwerecognize"
 	exeFile := "../data/bhello"
-	fmt.Printf("GetBinaryType(%v) = %v\n", fictionalFile, shared.GetBinaryType(fictionalFile))
-	fmt.Printf("GetBinaryType(%v) = %v\n", dataDir, shared.GetBinaryType(dataDir))
-	fmt.Printf("GetBinaryType(%v) = %v\n", sourceFile, shared.GetBinaryType(sourceFile))
-	fmt.Printf("GetBinaryType(%v) = %v\n", objectFile, shared.GetBinaryType(objectFile))
-	fmt.Printf("GetBinaryType(%v) = %v\n", exeFile, shared.GetBinaryType(exeFile))
 
-	plain := shared.IsPlainFile(fictionalFile)
+	var binaryFileType shared.BinaryType
+	binaryFileType = shared.GetBinaryType(fictionalFile)
+
+	if binaryFileType != shared.BinaryUnknown {
+		t.Errorf("GetBinaryType(%v) = %v\n", fictionalFile, binaryFileType)
+	} else if DEBUG {
+		fmt.Printf("GetBinaryType(%v) = %v\n", fictionalFile, binaryFileType)
+	}
+
+	binaryFileType = shared.GetBinaryType(dataDir)
+
+	if binaryFileType != shared.BinaryUnknown {
+		t.Errorf("GetBinaryType(%v) = %v\n", dataDir, binaryFileType)
+	} else if DEBUG {
+		fmt.Printf("GetBinaryType(%v) = %v\n", dataDir, binaryFileType)
+	}
+
+	binaryFileType = shared.GetBinaryType(sourceFile)
+	if binaryFileType != shared.BinaryUnknown {
+		t.Errorf("GetBinaryType(%v) = %v\n", sourceFile, binaryFileType)
+	} else if DEBUG {
+		fmt.Printf("GetBinaryType(%v) = %v\n", sourceFile, binaryFileType)
+	}
+
+	binaryFileType = shared.GetBinaryType(objectFile)
+	if binaryFileType != shared.BinaryObject {
+		t.Errorf("GetBinaryType(%v) = %v\n", objectFile, binaryFileType)
+	} else if DEBUG {
+		fmt.Printf("GetBinaryType(%v) = %v\n", objectFile, binaryFileType)
+	}
+
+	binaryFileType = shared.GetBinaryType(exeFile)
+	if binaryFileType != shared.BinaryExecutable {
+		t.Errorf("GetBinaryType(%v) = %v\n", exeFile, binaryFileType)
+	} else if DEBUG {
+		fmt.Printf("GetBinaryType(%v) = %v\n", exeFile, binaryFileType)
+	}
+
+	var plain bool
+	plain = shared.IsPlainFile(fictionalFile)
+
 	if plain {
 		t.Errorf("shared.IsPlainFile(%v) returned %v\n", fictionalFile, plain)
-	} else {
+	} else if DEBUG {
 		fmt.Printf("shared.IsPlainFile(%v) returned %v\n", fictionalFile, plain)
 	}
+
 	plain = shared.IsPlainFile(dataDir)
 	if plain {
 		t.Errorf("shared.IsPlainFile(%v) returned %v\n", dataDir, plain)
-	} else {
+	} else if DEBUG {
 		fmt.Printf("shared.IsPlainFile(%v) returned %v\n", dataDir, plain)
 	}
+
 	plain = shared.IsPlainFile(sourceFile)
 	if !plain {
 		t.Errorf("shared.IsPlainFile(%v) returned %v\n", sourceFile, plain)
-	} else {
+	} else if DEBUG {
 		fmt.Printf("shared.IsPlainFile(%v) returned %v\n", sourceFile, plain)
 	}
+
 	plain = shared.IsPlainFile(objectFile)
 	if !plain {
 		t.Errorf("shared.IsPlainFile(%v) returned %v\n", objectFile, plain)
-	} else {
+	} else if DEBUG {
 		fmt.Printf("shared.IsPlainFile(%v) returned %v\n", objectFile, plain)
 	}
+
 	plain = shared.IsPlainFile(exeFile)
 	if !plain {
 		t.Errorf("shared.IsPlainFile(%v) returned %v\n", exeFile, plain)
-	} else {
+	} else if DEBUG {
 		fmt.Printf("shared.IsPlainFile(%v) returned %v\n", exeFile, plain)
 	}