редактор потока (stream editor)
Операнды (Operands)
The following operands shall be supported:
file A pathname of a file whose contents are read and
edited. If multiple file operands are specified, the
named files shall be read in the order specified and
the concatenation shall be edited. If no file operands
are specified, the standard input shall be used.
script A string to be used as the script of editing commands.
The application shall not present a script that
violates the restrictions of a text file except that
the final character need not be a <newline>.
