# How to use the ul command line utility

I wanted to answer http://unix.stackexchange.com/questions/3043/use-roff-to-underline-words with "just use ul, this command is meant specifically for underlining text", however I just can't grasp how to use it. I thought

$echo "hello _kitty_ world" > /tmp/foo.txt$ ul /tmp/foo.txt

would give me an underlined "kitty", however it doesn't. What am I doing wrong?

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