/usr/bin/split

Usage: /usr/bin/split [OPTION]... [FILE [PREFIX]]
Output pieces of FILE to PREFIXaa, PREFIXab, ...;
default size is 1000 lines, and default PREFIX is 'x'.

With no FILE, or when FILE is -, read standard input.

Mandatory arguments to long options are mandatory for short options too.
  -a, --suffix-length=N
         generate suffixes of length N (default 2)
      --additional-suffix=SUFFIX
         append an additional SUFFIX to file names
  -b, --bytes=SIZE
         put SIZE bytes per output file
  -C, --line-bytes=SIZE
         put at most SIZE bytes of records per output file
  -d
         use numeric suffixes starting at 0, not alphabetic
      --numeric-suffixes[=FROM]
         same as -d, but allow setting the start value
  -x
         use hex suffixes starting at 0, not alphabetic
      --hex-suffixes[=FROM]
         same as -x, but allow setting the start value
  -e, --elide-empty-files
         do not generate empty output files with '-n'
      --filter=COMMAND
         write to shell COMMAND; file name is $FILE
  -l, --lines=NUMBER
         put NUMBER lines/records per output file
  -n, --number=CHUNKS
         generate CHUNKS output files; see explanation below
  -t, --separator=SEP
         use SEP instead of newline as the record separator;
         '\0' (zero) specifies the NUL character
  -u, --unbuffered
         immediately copy input to output with '-n r/...'
      --verbose
         print a diagnostic just before each output file is opened
      --help
         display this help and exit
      --version
         output version information and exit

The SIZE argument is an integer and optional unit (example: 10K is 10*1024).
Units are K,M,G,T,P,E,Z,Y,R,Q (powers of 1024) or KB,MB,... (powers of 1000).
Binary prefixes can be used, too: KiB=K, MiB=M, and so on.

CHUNKS may be:
  N       split into N files based on size of input
  K/N     output Kth of N to standard output
  l/N     split into N files without splitting lines/records
  l/K/N   output Kth of N to standard output without splitting lines/records
  r/N     like 'l' but use round robin distribution
  r/K/N   likewise but only output Kth of N to standard output

-n (except -nr) will buffer to $TMPDIR, defaulting to /tmp,
if the input size cannot easily be determined.

Report bugs to: <bug-coreutils@gnu.org>.
GNU coreutils home page: <https://www.gnu.org/software/coreutils/>
General help using GNU software: <https://www.gnu.org/gethelp/>
Full documentation <https://www.gnu.org/software/coreutils/split>
or available locally via: info '(coreutils) split invocation'