On Sun, Aug 3, 2025 at 15:33 PM Alexander Jones <happy5...@gmail.com> wrote:
> This may be a related issue. Were lines 4 and 6 of "filter.ed"
> supposed to have "!!" (double bang) instead of "!:" (bang-colon), with
> the intent of testing the cached sort command? I can't find a
> meaningful use for the colons currently in the file.
No, the script is correct. Antonio has evidently introduced vi-style
external filtering (hurrah!) - i.e., addressed lines are written to the
standard input of a shell command (`:' or `true' in this case), and
then the addressed lines are replaced by the standard output of the
shell command (i.e., nothing in the case of `true'). The effect is to
delete the addressed line (i.e., the first -`1!:' - and last - `$!:' -
in filter.ed).
