#!/bin/bash
# extract all postgres databases from a sql file created by pg_dumpall
# this script outputs one .sql file for each database in the original .sql file
# unless you pass the name of a database in the dump
if [ $# -lt 1 ]
then
echo "Usage: $0 <postgresql sql dump> [dbname]" >&2
exit 1
fi
DB_FILE=$1
DB_NAME=$2
if [ ! -f $DB_FILE -o ! -r $DB_FILE ]
then
echo "error: $DB_FILE not found or not readable" >&2
exit 2
fi
# this loops through all instances of "\connect databasename"
# and tells the line number. the $LINE variable will look like this:
# 3504:\connect databasename
egrep -n "\\connect\ $DB_NAME" $DB_FILE | while read LINE
do
# get "databasename" from "3504:\connect databasename"
DB_NAME=$(echo $LINE | awk '{print $2}')
echo "Evaluating $DB_NAME..."
# get "3504" from contains "3504:\connect databasename"
STARTING_LINE_NUMBER=$(echo $LINE | cut -d: -f1)
# the exported sql should not contain the first line that reads
# "\connect databasename" otherwise you won't be able to rename the database
# if we start after that line, you could do something like this:
# psql new_databasename < databasename.sql
STARTING_LINE_NUMBER=$(($STARTING_LINE_NUMBER+1))
# use tail to print out all of the file after the STARTING_LINE_NUMBER
TOTAL_LINES=$(tail -n +$STARTING_LINE_NUMBER $DB_FILE | \
# search for the line at the end of the sql import for this database
egrep -n -m 1 "PostgreSQL\ database\ dump\ complete" | \
# make sure we only act on the first match
head -n 1 | \
# and get the line number where we found the match
cut -d: -f1)
# we should now know how long the sql import is for this database
# specifically, we should know how many lines there are
echo "$DB_NAME begins on line $STARTING_LINE_NUMBER and ends after $TOTAL_LINES lines"
# use tail to pipe from the starting line number, and piping X amount of lines (where X is TOTAL_LINES)
# this gets piped into a file named after the database: DB_NAME.sql
tail -n +$STARTING_LINE_NUMBER $DB_FILE | head -n +$TOTAL_LINES > $DB_NAME.sql
done