Shell script to get per database stats

postgres_db_stats

#!/bin/bash

case $1 in
    pg_stat_activity)
        sudo -u postgres psql -t -c "select $3 from pg_stat_activity where datname='$2' ;" | head -1 | sed s/\ \\+//g
        ;;
    pg_stat_database)
        sudo -u postgres psql -t -c "select $3 from pg_stat_database where datname='$2' ;" | head -1 | sed s/\ \\+//g
        ;;
    pg_database_size)
        sudo -u postgres psql -t -c "select pg_database_size('$2');" | head -1 | sed s/\ \\+//g
        ;;
    *)
        exit 1;
        ;;
esac