I'm trying to configure conky on Ubuntu, because I need to display my todo list on the desktop.

The the file is displayed, but the text is truncated (not rectangular, just after some character limit).

How to display the whole file?

Here is my setup:

# Text alignment, other possible values are commented
alignment top_right

# Gap between borders of screen and text
gap_x 10
gap_y 10

# Maximum size of buffer for user text, i.e. below TEXT line.
max_user_text 16384

# stuff after 'TEXT' will be formatted on screen
TEXT
${execi 30 cat /home/user/Documents/todo.txt}