Creates a database with schema 'a' and schema 'b' containing databases given in parameters

create_ab.sh

#!/bin/bash

# This tool creates a database $3 from database $1 and database $2
# database $1 will ends in the schema a
# database $2 will ends in the schema b
# this will allow comparisons between two schemas in the same database

if [ "$1" = "" ]; then
  echo "USAGE: $0 <DBNAME_A> <DBNAME_B> <DBNAME_AB>" >&2
  exit 1
else
  DB_A=$1
fi

if [ "$2" = "" ]; then
  echo "USAGE: $0 <DBNAME_A> <DBNAME_B> <DBNAME_AB>" >&2
  exit 1
else
  DB_B=$2
fi

if [ "$3" = "" ]; then
  echo "USAGE: $0 <DBNAME_A> <DBNAME_B> <DBNAME_AB>" >&2
  exit 1
else
  DB_AB=$3
fi

spinner()
{
    local pid=$!
    local delay=0.4
    local spinstr='|/-\'
    while [ "$(ps a | awk '{print $1}' | grep $pid)" ]; do
        local temp=${spinstr#?}
        printf " [%c]  " "$spinstr"
        local spinstr=$temp${spinstr%"$temp"}
        sleep $delay
        printf "\b\b\b\b\b\b"
    done
    printf "    \b\b\b\b\n"
}


#CREATE DB
printf "createdb $DB_AB\n"
if ! createdb $DB_AB
then 
    printf "[ERROR] please use a non-existing database $DB_AB\n"
    exit 1 
fi


#GENERATE DUMPS
printf "pg_dump -Ox $DB_A > /tmp/a.sql"
pg_dump -Ox $DB_A > /tmp/a.sql & spinner
printf "pg_dump -Ox $DB_B \> /tmp/b.sql"
pg_dump -Ox $DB_B > /tmp/b.sql  & spinner

#IMPORTING DUMP
printf "cat /tmp/a.sql | psql $DB_AB > /tmp/import_$DB_A.log"
cat /tmp/a.sql | psql $DB_AB > /tmp/import_$DB_A.log & spinner

echo $DB_AB\#= alter schema public rename to a;
psql $DB_AB -c "alter schema public rename to a;"
echo $DB_AB\#= create schema public;
psql $DB_AB -c "create schema public;"

printf "cat /tmp/b.sql | psql $DB_AB > /tmp/import_$DB_B.log"
cat /tmp/b.sql | psql $DB_AB > /tmp/import_$DB_B.log & spinner

echo $DB_AB\#= alter schema public rename to b;
psql $DB_AB -c "alter schema public rename to b;"
echo $DB_AB\#= create schema public;
psql $DB_AB -c "create schema public;"

#CLEANING
echo rm /tmp/a.sql
rm /tmp/a.sql
echo rm /tmp/b.sql
rm /tmp/b.sql