To get the absolute path to directory in which the bash script resides
SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"Always forgetting this very important utility.
strvar=$(cat << EOF
# all content goes here, bash variables work.
EOF
)To directly put the output into a file
cat << EOF > /path/to/file
# all content goes here, bash variables work.
EOF
)