Get the directory the current bash script is located in.

bash_script_source_dir.sh

# From discussion at http://stackoverflow.com/questions/59895/can-a-bash-script-tell-what-directory-its-stored-in

DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
# Is a useful one-liner which will give you the full directory name of the script no matter where it is being
# called from

# Or, to get the dereferenced path (all directory symlinks resolved), do this:

DIR="$( cd -P "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
# These will work as long as the last component of the path used to find the 
# script is not a symlink (directory links are OK). If you want to also resolve any links to the script itself,
# you need a multi-line solution:

SOURCE="${BASH_SOURCE[0]}"
while [ -h "$SOURCE" ] ; do SOURCE="$(readlink "$SOURCE")"; done
DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
# This last one will work with any combination of aliases, source, bash -c, symlinks, etc.

The last example doesn't work if the symlink is a relative path and the directory it's executed from is not the directory containing the script.