Usage: split [OPTION]... [INPUT [PREFIX]]
Output fixed-size pieces of INPUT to PREFIXaa, PREFIXab, ...; default
size is 1000 lines, and default PREFIX is `x'. With no INPUT, or when INPUT
is -, read standard input.

Mandatory arguments to long options are mandatory for short options too.
 -a, --suffix-length=N  use suffixes of length N (default 2) 指定拆分文件的后缀长度
 -b, --bytes=SIZE    put SIZE bytes per output file 按字节拆分，默认单位字节
 -C, --line-bytes=SIZE  put at most SIZE bytes of lines per output file 指定单行的最大大小，默认单位字节
 -d, --numeric-suffixes use numeric suffixes instead of alphabetic 用数字作为拆分文件的后缀
 -l, --lines=NUMBER   put NUMBER lines per output file 按行数进行拆分
   --verbose      print a diagnostic just before each
              output file is opened
   --help   display this help and exit
   --version output version information and exit

split -l 300 large_file.txt new_file_prefix

split -b 10m server.log waynelog

cat small_files* > large_file