Shell Programming and Scripting

#!/usr/bin/perl

@a=qw(acc faf prom subs);
opendir(DH,"/dir/path");
$flg=1;
@files=grep(/.*\.csv/,readdir(DH));
while (<@files>) {
undef $file_Pre;
if (/(.+?[_-]\d{14}[_-])(.+?)\.csv$/){
        for ($i=0;$i<=$#a;$i++) {
                $file_Pre .= $1 . $a[$i]."\.csv";
                if ( ! -e $file_Pre ) {system("touch $file_Pre"); }
                undef $file_Pre;
        }
}
}

close(DH);