File1:

Item,Period,Waveform,Attributes,Sources
an_en11,200.00,{0 133},{ }
br_gh13,140.09,{0 59},{ }
ce_oy74,300.05,{0 230},{int_43}
dt_pp50,200.11,{0 122},{ }
er_tk02,305.47,{0 220},{ }
ef_yb41,200.05,{0 233},{ }

File2:

Item,Sink,Buffer,Cell,Slew,Path,Violation,Area 
dt_pp50,0,0,2,0.000,0.000,0,0.000
er_tk02,0,2,3,0.002,0.004,0,0.001
ef_yb41,0,1,5,0.000,0.000,0,0.000


##</code><code>##

Item,Sink,Buffer,Cell,Slew,Path,Violation,Area,Period,%Skew
dt_pp50,0,0,2,0.000,0.000,0,0.000,200.11,(Slew/Period)x100%
er_tk02,0,2,3,0.002,0.004,0,0.001,305.47,(Slew/Period)x100%
ef_yb41,0,1,5,0.000,0.000,0,0.000,200.05,(Slew/Period)x100%


##</code><code>##

#! /usr/intel/bin/perl-w
use strict;
use warnings;

my %file1Hash;
my $value1;
	
open my $file1, "<","design.rpt.csv"; 
open my $file2, "<","summary.rpt.csv"; 
open my $outfile_1, ">", "combined.rpt.csv";

print $output_1 "Item, Sink, Bufer, Cells, Slew, Path, Violation, Area, Period, %Skew\n";
while(my $line = <$file1>){
		
	chomp $line; 
	my($key, $value1) = (split /,/, $line);
	if (defined $key) {
		$file1Hash{$key}= $value1;	
				
		    }
	else {
		# print $line."\n";
		    } 	
	} 
		
while(my $line1 = <$file2>){ 
		
	chomp $line1; 
	my($key1) = (split /,/, $line1) ; 
		
	if (defined $file1Hash{$key1}) {
		print $outfile_1 $line1.",".$file1Hash{$key1}."\n";			
		    } 
	else {
#		 print $line1."\n";
		    } 
} 

close $file1;
close $file2;
close $outfile_1;