# How to avoid alltt skipping a line?

The environment alltt skips a line before and after its use. Is there a way to modify this behaviour to avoid these empty lines ?

*** Edit I tried to get inspired by a similar post about figure but I am a noob and don't really understand how to modify the answer.

Like most latex displays it is a list and so has \topsep spacing above it (note thiis is stretchable vertical space not really a blankline) You can set it to 0 eiether inline or in a \newenvironment definition

\documentclass{article}
\usepackage{alltt}
\begin{document}

xxxxxxxxxxxxxxxxxxxx
{\setlength\topsep{0pt}\begin{alltt}
one two three
four five six
\end{alltt}}%
xxxxxxxxxxxxxxxxxxxxxxx
\end{document}


to redefine alltt to always do this you can use

\let\oldalltt\alltt
\let\endoldalltt\endalltt
\renewenironment{alltt}{\setlength\topsep{0pt}\oldalltt}{\endoldalltt}

• thanks, but this affect all the list-type environment then? is there a way to redefine the alltt environment (with \renewenvironment like in the mentioned question) to alter only alltt? – ClementWalter Oct 14 '16 at 17:32
• @clemlaflemme as above it only affects this instance (note the {} group around the setting. simplest definition if you want lots of these is just \newenvironment{alltt2}{\setlength\topsep{0pt}\alltt}{\endalltt} – David Carlisle Oct 14 '16 at 17:40
• the main thing is that I use knitr which produce .tex with alltt environments. That's why I'd like to redefine this environment, and not define to define a new one with another name. – ClementWalter Oct 14 '16 at 17:44
• @clemlaflemme sigh, you could have said:-) I'll add something to the answer – David Carlisle Oct 14 '16 at 17:46
• @clemlaflemme I added the saving of the end code, sorry, can't help with knitr – David Carlisle Oct 18 '16 at 8:29