$str='ABCD----[this]  fgab [that]  BFTE-- [other] AB CD   EF---- [foo]';

$hash{$1}=$2 while ($str=~m#\s*([\w ]+)[\s-]+\[([^\]]+)\]#g);

print "$_=$hash{$_}\n" for keys %hash;

##</code><code>##

fgab=that
ABCD=this
BFTE=other
AB CD   EF=foo