Implementing change directory command

server/server/commands.go

@@ -11,7 +11,10 @@ import (
 
 // GetFile sends the file to the client and returns true if it succeeds and false otherwise.
 func GetFile(c Client, path string) (int, error) {
-	fileName := sanitizeFilePath(path)
+	fileName, sanitized := sanitizeFilePath(path)
+	if sanitized {
+		return 0, ErrSlashNotAllowed
+	}
 
 	stack, ok := c.Stack().(*StringStack)
 	if !ok {
@@ -51,17 +54,20 @@ func readFileData(file *os.File) ([]byte, error) {
 	return data, nil
 }
 
-func sanitizeFilePath(path string) string {
+func sanitizeFilePath(path string) (string, bool) {
 	var fileName string
+	var sanitized bool
 	// Make sure the user can't request any files on the system.
 	lastForwardSlash := strings.LastIndex(path, "/")
 	if lastForwardSlash != -1 {
 		// Eliminate the last forward slash i.e ../../asdas will become asdas
 		fileName = path[lastForwardSlash+1:]
+		sanitized = true
 	} else {
 		fileName = path
+		sanitized = false
 	}
-	return fileName
+	return fileName, sanitized
 }
 
 // ListFiles list the files from path and sends them to the connection
@@ -90,13 +96,46 @@ func ListFiles(c Client) error {
 	return nil
 }
 
+// ClearScreen cleans the client's screen by sending clear to the terminal.
+func ClearScreen(c Client) error {
+	// Ansi clear: 1b 5b 48 1b 5b 4a
+	// clear | hexdump -C
+	var b = []byte{0x1b, 0x5b, 0x48, 0x1b, 0x5b, 0x4a}
+	_, err := c.Connection().Write(b)
+
+	return err
+}
+
+// ChangeDirectoryCommand changes the directory to the given directory
+func ChangeDirectoryCommand(c Client, directory string) error {
+	var err error
+	path, sanitized := sanitizeFilePath(directory)
+	if sanitized {
+		return ErrSlashNotAllowed
+	}
+
+	stack, ok := c.Stack().(*StringStack)
+	if !ok {
+		return ErrStackCast
+	}
+
+	if path == ".." {
+		err = ChangeDirectoryToPrevious(stack)
+	} else {
+		err = ChangeDirectory(stack, path)
+	}
+
+	return err
+}
+
 func ShowHelp(c Client) error {
 	var helpText = `
 The available commands are:
 get <filename> - Download the requested filename.
 ls             - List the files in the current directory.
+cd             - Changes the directory.
 clear          - Clear the screen.
-exit - Close the connection with the server.
+exit           - Close the connection with the server.c
 `
 	_, err := c.Connection().Write([]byte(helpText))
 

server/server/errors.go

@@ -44,4 +44,5 @@ var (
 	ErrInvalidDirectoryName   = errors.New("names should not contain / character")
 	ErrNotADirectory          = errors.New("file name is not a valid directory")
 	ErrAlreadyAtBaseDirectory = errors.New("can't go past beyond root directory")
+	ErrSlashNotAllowed        = errors.New("slash is not allowed in file names")
 )

server/server/parser.go

@@ -25,6 +25,16 @@ func ProcessInput(c Client, text string) error {
 	thisCommand := commands[0]
 
 	switch thisCommand {
+	case "cd":
+		err := checkArgumentsLength(commandsLen, 2)
+		if err != nil {
+			return &InputError{thisCommand, err}
+		}
+
+		err = ChangeDirectoryCommand(c, commands[1])
+		if err != nil {
+			return err
+		}
 	case "get":
 		err := checkArgumentsLength(commandsLen, 2)
 		if err != nil {
@@ -52,11 +62,10 @@ func ProcessInput(c Client, text string) error {
 			return &InputError{thisCommand, err}
 		}
 
-		// Ansi clear: 1b 5b 48 1b 5b 4a
-		// clear | hexdump -C
-		var b = []byte{0x1b, 0x5b, 0x48, 0x1b, 0x5b, 0x4a}
-
-		c.Connection().Write(b)
+		err = ClearScreen(c)
+		if err != nil {
+			return err
+		}
 	case "help":
 		// Check arguments
 		err := checkArgumentsLength(commandsLen, 1)

server/server/path.go

@@ -18,17 +18,17 @@ func containsSlash(dir string) bool {
 }
 
 // PATH is the constant which should contain the fixed path where the simpleFTP server will run
-// This will act like a root cage.
+// This will act like a root cage. It must end with a forward slash!
 var BasePath = "/Users/denis/GoglandProjects/golangBook/"
 
 // GetPath will return the complete path
-func GetPath(stack *StringStack) string {
-	if stack.IsEmpty() {
-		return BasePath
-	}
-
-	return BasePath
-}
+//func GetPath(stack *StringStack) string {
+//	if stack.IsEmpty() {
+//		return BasePath
+//	}
+//
+//	return BasePath
+//}
 
 // MakePathFromStringStack gets a StringStack and makes a path.
 func MakePathFromStringStack(stack *StringStack) string {
@@ -56,10 +56,12 @@ func ChangeDirectory(stack *StringStack, directory string) error {
 	path := MakePathFromStringStack(stack)
 	fileInfo, err := os.Stat(path)
 	if err != nil {
+		stack.Pop()
 		return err
 	}
 
 	if fileInfo.IsDir() == false {
+		stack.Pop()
 		return ErrNotADirectory
 	}
 

server/server/path_test.go

@@ -7,16 +7,6 @@ import (
 	"testing"
 )
 
-func TestGetPath_StackIsEmpty(t *testing.T) {
-	st := MakeStringStack(1)
-
-	path := GetPath(st)
-
-	if path != BasePath {
-		t.Errorf("TestGetPath: Base path is not returned when stack is empty.")
-	}
-}
-
 func TestMakePathFromStringStack(t *testing.T) {
 	st := MakeStringStack(5)
 
@@ -25,7 +15,7 @@ func TestMakePathFromStringStack(t *testing.T) {
 	st.Push("trinity")
 
 	path := MakePathFromStringStack(st)
-	expected := fmt.Sprintf("%s/%s/%s/%s/", BasePath, "first", "folder two", "trinity")
+	expected := fmt.Sprintf("%s%s/%s/%s/", BasePath, "first", "folder two", "trinity")
 
 	if path != expected {
 		t.Errorf("TestMakePathFromStringStack: Returned an invalid path! Want %s Got %s", expected, path)
@@ -77,6 +67,23 @@ func TestChangeDirectory(t *testing.T) {
 	}
 }
 
+func TestChangeDirectory_InvalidDirectoryIsNotInStack(t *testing.T) {
+	st := MakeStringStack(1)
+	err := os.Chdir(BasePath)
+	if err != nil {
+		t.Errorf("TestChangeDirectory_InvalidDirectoryIsNotInStack: Step1: %s", err.Error())
+	}
+
+	dirName := string(rand.Intn(10000))
+
+	// ignore no such directory error
+	ChangeDirectory(st, dirName)
+	if !st.IsEmpty() && st.Top() == dirName {
+		t.Errorf("TestChangeDirectory: Stack is corrupted because invalid directory remained in stack")
+	}
+
+}
+
 func TestChangeDirectory_InvalidDirectoryName(t *testing.T) {
 	st := MakeStringStack(1)
 	err := ChangeDirectory(st, "some/not/cool/directory/")