@@ -19,10 +19,13 @@ PostgresNode - class representing PostgreSQL server instance
1919 # Start the PostgreSQL server
2020 $node->start();
2121
22- #Change a setting and restart
22+ #Add a setting and restart
2323 $node->append_conf('postgresql.conf', 'hot_standby = on');
2424 $node->restart();
2525
26+ # Modify or delete an existing setting
27+ $node->adjust_conf('postgresql.conf', 'max_wal_senders', '10');
28+
2629 # run a query with psql, like:
2730 # echo 'SELECT 1' | psql -qAXt postgres -v ON_ERROR_STOP=1
2831 $psql_stdout = $node->safe_psql('postgres', 'SELECT 1');
@@ -544,6 +547,50 @@ sub append_conf
544547
545548=pod
546549
550+ =item $node->adjust_conf(filename, setting, value, skip_equals)
551+
552+ Modify the named config file setting with the value. If the value is undefined,
553+ instead delete the setting. If the setting is not present no action is taken.
554+
555+ This will write "$setting = $value\n" in place of the existing line,
556+ unless skip_equals is true, in which case it will write
557+ "$setting $value\n". If the value needs to be quoted it is the caller's
558+ responsibility to do that.
559+
560+ =cut
561+
562+ sub adjust_conf
563+ {
564+ my ($self ,$filename ,$setting ,$value ,$skip_equals ) =@_ ;
565+
566+ my $conffile =$self -> data_dir .' /' $filename ;
567+
568+ my $contents = TestLib::slurp_file($conffile );
569+ my @lines =split (/ \n / $contents );
570+ my @result ;
571+ my $eq =$skip_equals ?' ' ' ='
572+ foreach my $line (@lines )
573+ {
574+ if ($line !~/ ^$setting \W /
575+ {
576+ push (@result ," $line \n "
577+ }
578+ elsif (defined $value )
579+ {
580+ push (@result ," $setting $eq$value \n "
581+ }
582+ }
583+ open my $fh ," >" $conffile
584+ or croak" could not write\" $conffile \" :$! "
585+ print $fh @result ;
586+ close $fh ;
587+
588+ chmod ($self -> group_access() ? 0640 : 0600,$conffile )
589+ or die (" unable to set permissions for$conffile "
590+ }
591+
592+ =pod
593+
547594=item $node->backup(backup_name)
548595
549596Create a hot backup withB<pg_basebackup > in subdirectoryB<backup_name > of