Re: a sed question

On 21/12/2024 12:17, Salvador Mirzo wrote:

I'm studying and I often go back to the past to see what life was I
like.  I initially tried to solve the problem with /ed/, but did not
find a way to insert a string coming from the a shell script's cmdline.
Then I thought that /sed/ was there to make /ed/ more scriptable.

I think the other contributors are somewhat harsh on Sed.  For
those who started on V6 Unix, there was just Ed, and, as you thought,
Sed was added in V7 as a scripting improvement to Ed.  Awk also came
in with V7.  Some people adopted Awk with enthusiasm, but the early
versions were quite limited/buggy, partly thanks to the limitations of
the PDP-11;  Sed was pretty reliable even in those days.  So at least
some users tried and failed with Awk, but found Sed usable with very
little to learn, thanks to the relationship with Ed.  The arcana of
Sed are much easier to understand if you are/were a regular user of Ed,
whereas Awk requires you to learn a whole new language [I'm not in any
way suggesting that that is unusually difficult].
So students will normally no longer learn or use Ed/Sed, apart
perhaps from "s/foo/bar/" and similar;  it makes more sense to learn a
visual editor and Awk.  But for older hands, and for those interested
in the history, there is still a use for Sed.  Personally, I know my
way around Sed much better than Awk.  So, again personally, Sed is my
stream editor of choice for tasks somewhat harder than "s ...", but not
so hard that I need to do some serious programming and checking of the
documentation.  [YMMV, and I'm certainly not trying to persuade any Awk
users that they should learn to use Sed instead.]
--
Andy Walker, Nottingham.
    Andy's music pages: www.cuboid.me.uk/andy/Music
    Composer of the day: www.cuboid.me.uk/andy/Music/Composers/Paderewski