HJSplit for Linux is a freeware file splitter for Linux with full graphical user-interface.
Download ‘HJSplit’ from Freebytesoftware
Unix Split command
$ split -l 1000 my_file.txt # Split the file named my_file.txt into several files with 1000 lines
$ split -b n my_file.txt # Split a file into pieces n bytes in size.