$filename = "output.txt";
system("perl /absolute/path/to/program1> $filename");

##</code><code>##

...
print "Start xxx job...";
# some code to do the job
print "End of doing xxx job.";

##</code><code>##

(program1.pl)
$projectSourceDir ='/absolute/path';
chdir $projectSourceDir;
print "Do cvs update ...\n";
	
open INFO, "cvs update -dP |";
my @cvsInfo = <INFO>;
close INFO;
my $cvsInfo= join("", @cvsInfo);
		
print "$cvsInfo";
print "done\n\n";