This script aims to clear all (yes. really all) caches being used by TYPO3. So the file caches in typo3temp and typo3conf/autoload, next the database caches in tables cf_* and eventual realurl caches. And finally any PHP caches like those from APC, xcache, or other PHP accelerators/compilers.
Simply install the script at some executable location on your webserver or local dev machine (like in $HOME/bin, etc.). Then use the script in the same way as "typo3-instance-sqlshell.sh" by pointing it to the path of the instance:
clearCache.sh /path/to/TYPO3/webroot
Of course you can call "clearCache.sh ." if you are directly in the TYPO3 webroot.
A nice way to install this script is to check out the GIST/github repository in your executable location ($HOME/bin) and create a symlink to the script. This way you can easily update to new versions of the script:
cd $HOME/bin
git clone https://gist.github.com/1851dd848fb1654c9f83.git
ln -s 1851dd848fb1654c9f83/clearCache.sh
git clone https://gist.github.com/a3becef65ad853243fe2.git
ln -s a3becef65ad853243fe2/typo3-instance-sqlshell.sh
You also need "typo3-instance-sqlshell.sh" installed.
When installing this (those) scripts on MAC OS you will probably need to install a mysql client (for typo3-instance-sqlshell.sh) and the coreutil tool package to have "readlink" available:
brew install mysql
brew install coreutils