fsplit —
split a multi-routine Fortran file into individual files
  
    | fsplit | [ -eefile] ...
      [file] | 
fsplit takes as input either a file or standard input
  containing Fortran source code. It attempts to split the input into separate
  routine files of the form name.f, where
  name is the name of the program unit (e.g. function,
  subroutine, block data or program). The name for unnamed block data
  subprograms has the form blkdtaNNN.f where NNN is three
  digits and a file of this name does not already exist. For unnamed main
  programs the name has the form mainNNN.f. If there is an
  error in classifying a program unit, or if name.f
  already exists, the program unit will be put in a file of the form
  zzzNNN.f where zzzNNN.f does not
  already exist.
  - -eefile
- Normally each subprogram unit is split into a separate file. When the
      -eoption is used, only the specified subprogram
      units are split into separate files. E.g.:fsplit -e readit -e doit
      prog.f
 will split readit and doit into separate files. 
If names specified via the-e option are not found, a
  diagnostic is written to standard error.
The fsplit command appeared in
  4.2BSD.
Asa Romberger and Jerry Berkman
fsplit assumes the subprogram name is on the first
  noncomment line of the subprogram unit. Nonstandard source formats may confuse
  fsplit.
It is hard to use -e for unnamed main
    programs and block data subprograms since you must predict the created file
    name.