perl -e 'push @file,$_ while<>;print sort {$a <=> $b} @file' test.txt

##</code><code>##

perl -e "push @file,$_ while<>;print sort {$a <=> $b} @file" test.txt

##</code><code>##

1       b005824
134     b005376
402     astamen
972     achin00
181847  azeleke
1260896 abadeno