Get Path to Currently Executing Bash Script

This Bash one-liner should return the full path to the script from which it is being executed.

SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

The above may not work as expected with symlinks. A more robust (and verbose) solution is as follows:

# 
# Returns the full path to the script it is called in.
#
function SCRIPT_DIR() {
    SCRIPT_DIR=''
    SOURCE="${BASH_SOURCE[0]}"
    while [ -h "$SOURCE" ]; do
        SCRIPT_DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
        SOURCE="$(readlink "$SOURCE")"
        [[ $SOURCE != /* ]] && SOURCE="$SCRIPT_DIR/$SOURCE" 
    done
    SCRIPT_DIR="$( cd -P "$( dirname "$SOURCE" )" && pwd )"
}

References

Can a Bash script tell what directory it's stored in?