$ perl -e 'print (("x" x 5000 . "\n") x 3);' | cat | wc
3 3 15003
$ perl -e 'print (("x" x 5000 . "\n") x 3);' | unbuffer -p cat | wc
1 1 906
It doesn't just truncate the long line; it loses the rest of the output.
If this is a hard-to-avoid limitation please document it in the man
page. It might have saved me some time if I'd known. Thanks.
(What I was trying to do was attach a timestamp to each line in the
output from sbuild. Any suggestions?)