Serial port to USB on Mac

This link provides the detailed the solution.

http://www.planet-rcs.de/article/mac_serial_port/

Note:
1. make sure you are using PL-2303 cable
2. In addition to the software mentioned in the link, you could use minicom. It has the same function in Linux.

Install Xcode on Lion 10.7

After install XCode from app store, the terminal still doesn't recognize Unix command: make, gcc.
You need go to apple development website to download "command line tools for xcode".dmg file.
and install it.

https://developer.apple.com/downloads/index.action#

comment package cannot be used by latexdiff

main.tex
\usepackage{comment}

background.tex


\begin{comment}

\end{comment}

if run command at article-latexdiff
error message:
File ended while scanning use of \next.

Need to remove

\begin{comment}

\end{comment}