Reset root password for PostgreSQL

EITHER:

$ ps -ef | grep postgres

postgres  3940     1  0 12:38 ?        00:00:00 /usr/lib/postgresql/8.4/bin/postgres -D /var/lib/postgresql/8.4/main -c config_file=/etc/postgresql/8.4/main/postgresql.conf

$ grep 'hba_file' /etc/postgresql/8.4/main/postgresql.conf

hba_file = '/etc/postgresql/8.4/main/pg_hba.conf' # host-based authentication file

# vi /etc/postgresql/8.4/main/pg_hba.conf

OR:

# vi $(grep 'hba_file' $(ps -ef | grep postgres | awk '{ if ( $3 == 1 ) print $NF }' | cut -d '=' -f 2) | cut -d "'" -f 2)

#local all postgres md5
local all postgres trust

# service postgresql-8.4 restart

# su - postgres

$ psql -d template1 -U postgres

> alter user postgres with password 'new_password';

# vi /etc/postgresql/8.4/main/pg_hba.conf


OR:

# vi $(grep 'hba_file' $(ps -ef | grep postgres | awk '{ if ( $3 == 1 ) print $NF }' | cut -d '=' -f 2) | cut -d "'" -f 2)


local all postgres md5
#local all postgres trust

# service postgresql-8.4 restart

$ psql -d template1 -U postgres