int close( int fh )

	- prototype in io.h

	- closes file fh where fh is file handle from _creat(), creat(),
	  creatnew(), creattemp(), dup(), dup2(), _open(), or
	- use fdopen() to change file handle to file stream
	- does not write a Ctrl-Z to a text file on closing
	- returns 0 if OK; else -1 & errno may be set of EBADF