perl -F'\t' -ane 'open (A, "$F[0].xml"); open(B, ">$F[0]") ;while(<F>) { print B; if ($.==4) { print B "  <keywords> ".substr($F[1],0,-1)." </keywords>\n" ; }} close(A); close(B); unlink("$F[0].xml"); rename($F[0], "$F[0].xml");' keywords.txt