my $test = qq|
sdfiojs pfojsdfs fs [img]sdj fpsdofj spojf sfsf [b] [img]http://www.test.com/image.gif[/img] dfs fs
s fsf sfd  [img]test.gif[/img]
|;

while ($test =~ m{\[img\]([^\[\]]*)\[/img\]}g) {
	print "$1\n";
}