tail(1) -f -n +1
output the last part of files
-f, --follow[={name|descriptor}]
       output appended data as the file grows; -f, --follow, and --follow=descriptor are equivalent
-n, --lines=K
       output  the  last  K lines, instead of the last 10; or use -n +K to output lines starting with the
       Kth
source manpages: tail