bash boilerplate -- http://kvz.io/blog/2013/11/21/bash-best-practices/

boilerplate.sh

#!/usr/bin/env bash
# Bash3 Boilerplate. Copyright (c) 2014, kvz.io

set -o errexit
set -o pipefail
set -o nounset
# set -o xtrace

# Set magic variables for current file & dir
__dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
__root="$(cd "$(dirname "${__dir}")" && pwd)" # <-- change this
__file="${__dir}/$(basename "${BASH_SOURCE[0]}")"
__base="$(basename ${__file} .sh)"

arg1="${1:-}"

# It often simplifies input/output logic to let the script operate 
# in a fresh working directory by using:

pushd $(mktemp -d)

# and then fill that directory with various output files.