line1=10
line2=30
line3= I am a monk
line4=true
.....
....
....

##</code><code>##

open OUTFILE, "<$outfile";
open FINAL, ">$final";

while (<OUTFILE>) {
    print FINAL if /(line1=\d+)/;
    print FINAL if /(line2=\d+)/;
    print FINAL if /(line3=\d+)/;
    ..........
}