open & write: Process regular files only

internal/buffer/buffer.go

@@ -237,10 +237,6 @@ func NewBufferFromFileAtLoc(path string, btype BufType, cursorLoc Loc) (*Buffer,
 		return nil, err
 	}
 
-	f, err := os.OpenFile(filename, os.O_WRONLY, 0)
-	readonly := os.IsPermission(err)
-	f.Close()
-
 	fileInfo, serr := os.Stat(filename)
 	if serr != nil && !os.IsNotExist(serr) {
 		return nil, serr
@@ -248,6 +244,13 @@ func NewBufferFromFileAtLoc(path string, btype BufType, cursorLoc Loc) (*Buffer,
 	if serr == nil && fileInfo.IsDir() {
 		return nil, errors.New("Error: " + filename + " is a directory and cannot be opened")
 	}
+	if serr == nil && !fileInfo.Mode().IsRegular() {
+		return nil, errors.New("Error: " + filename + " is not a regular file and cannot be opened")
+	}
+
+	f, err := os.OpenFile(filename, os.O_WRONLY, 0)
+	readonly := os.IsPermission(err)
+	f.Close()
 
 	file, err := os.Open(filename)
 	if err == nil {

internal/buffer/save.go

@@ -162,6 +162,17 @@ func (b *Buffer) saveToFile(filename string, withSudo bool, autoSave bool) error
 	// Removes any tilde and replaces with the absolute path to home
 	absFilename, _ := util.ReplaceHome(filename)
 
+	fileInfo, err := os.Stat(absFilename)
+	if err != nil && !errors.Is(err, fs.ErrNotExist) {
+		return err
+	}
+	if err == nil && fileInfo.IsDir() {
+		return errors.New("Error: " + absFilename + " is a directory and cannot be saved")
+	}
+	if err == nil && !fileInfo.Mode().IsRegular() {
+		return errors.New("Error: " + absFilename + " is not a regular file and cannot be saved")
+	}
+
 	// Get the leading path to the file | "." is returned if there's no leading path provided
 	if dirname := filepath.Dir(absFilename); dirname != "." {
 		// Check if the parent dirs don't exist