Splitting and merging file

Hello all, To split file into pieces, we use the split filename --bytes=1300000 General syntax: split filename --bytes=[number of bytes] Example: split sendmail.tar.bz2 --bytes=130000 After splitting, we will get these files xaa, xab, ... and so on. I would like to ask you, how can I merge all these files back? Thank you so much for your assistance. Best regards, Chan Choth