the scanning perl program gen.pl:
---------------------------------
#!/usr/bin/perl
use strict;
my @array = qw(13470319 13470331 15460001 13490216);
my @array2;

while(my $line =  <> ) {
    foreach my $id (0..$#array) {
        $array2[$id]=$line if $line =~  m/^gi\|($array[$id])\|/;
    }
}
print "order: ", join (" ", @array), "\n";
map {print} @array2;
-------------------------------
the text file:
gi|13470331|ref|NP_101896.1| hypothetical protein
MFWVTKKALMPFLMLPAGIIFVSAVGYAINWLFSTLFQFQPPLVEGPAGPVTVLIFTITMLLAYDISYYL
gi|13470319|ref|NP_101897.1| hypothetical protein
MGAYCQAHPACKVTDRTVIGRRDAAMNAPFVLAIPRTRTFEVVTSAARLAEIAPAWTALWQRAGGLVFQH
-------------------------------
the execution:
# cat gen.txt | perl gen.pl
order: 13470319 13470331 15460001 13490216
gi|13470319|ref|NP_101897.1| hypothetical protein
gi|13470331|ref|NP_101896.1| hypothetical protein