split divides a file in equal parts. Part files are stored in files names PREFIXaa, PREFIXab, PREFIXac, etc.

By default, PREFIX is x and the division is made by chunk of 1000 lines.

split options meaning
-a n generate suffix of length n (default is 2 => aa, ab, ac, etc.)
-l n split every n lines
-b n split every n bytes
-d use a numerical suffix instead of alphabetical (00, 01, 02, etc.)