Determine the path of the executing BASH script [duplicate]

For the relative path (i.e. the direct equivalent of Windows’ %~dp0):

MY_PATH="$(dirname -- "${BASH_SOURCE[0]}")"
echo "$MY_PATH"

For the absolute, normalized path:

MY_PATH="$(dirname -- "${BASH_SOURCE[0]}")"            # relative
MY_PATH="$(cd -- "$MY_PATH" && pwd)"    # absolutized and normalized
if [[ -z "$MY_PATH" ]] ; then
  # error; for some reason, the path is not accessible
  # to the script (e.g. permissions re-evaled after suid)
  exit 1  # fail
fi
echo "$MY_PATH"