For processing other things while using Marked.app (e.g., less files into a CSS custom style). Use as a preprocessing script.

mess.sh

#!/bin/bash

# mess.sh for processing other things while using Marked.app (VERSION 2013-10-10)
# Michael Tofias http://tofias.net 

# Grab the text off of stdin
THETEXT=$(cat);

# Run any scripts you might want to run, such as less (see http://lesscss.org)
lessc $MARKED_ORIGIN/styles.less > ~/Library/Application\ Support/Marked/Custom\ CSS/styles.css;

# push the text off to stdout
echo "$THETEXT";