FILE 1

complex.1    1.356
complex.2    1.879
etc

file 2
12.02   /home/complex.2out
10.25   /home/complex.1out
etc

##</code><code>##

$string = 'complex';

open(REF, "<file1");
chomp;

my %pd_file = map { /^(\S+)\s+(\S+).*/;  } <REF>;

close(REF);

open (ET, "<file2");
while (<ET>) {
   chomp;
/^(\S+\s+\S+)\s+.*($string\.\d+).*$/;
   print OUT  ($1,  $pd_file{$2}) if (exists($pd_file{$2}));

##</code><code>##

complex.1  10.25
complex.2  12.02