Grab all table columns only without any additional information from postgres. Ugly but works for me.

list_all_tables_columns_only.sh

#!/bin/bash

for t in $(echo '\dt' | psql "$1" | cut -d '|' -f 2 | egrep -v 'List|Name|--|\(')
  do echo "TABLE: $t"
  echo "\d $t" | psql "$1" | grep '|' | egrep -v Column | cut -d '|' -f 1
  echo
done