I don't fully understand your question, but here are some examples that may be a step in the right direction:
$ seq 1 5 | sed -e '1~2s/$/ --/' 1 -- 2 3 -- 4 5 -- $ seq 1 5 | sed -e '0~2s/$/ --/' 1 2 -- 3 4 -- 5 $ echo -e "2012-10-01,16:00,297.94\n2012-10-01,16:00,297.94" | sed -e '0~2s/16:00/17:00/' 2012-10-01,16:00,297.94 2012-10-01,17:00,297.94 Good luck and let us know how things go. Regards, - Robert On Tue, Jun 19, 2018 at 11:52 AM, Rich Shepard <rshep...@appl-ecosys.com> wrote: > I made a mistake when writing an awk script that inserts the time of an > observation with its value. I had 16:00 twice in a row rather than 16:00 and > 17:00. This holds for every day in the year, and I have about 12 year's in > which to make the correction. Specifically, changing the second 16:00 to > 17:00. A sample: > > 2012-10-01,16:00,297.94 > 2012-10-01,16:00,297.94 > > I'm stuck trying to find a way to make the change using sed, awk, or grep. > How do I ignore the first instance and change only the second instance? > > If there's a perl script to do this, please share it with me as I'm not a > perl coder. > > I'm looking forward to learning how to do this job. > > Rich > _______________________________________________ > PLUG mailing list > PLUG@pdxlinux.org > http://lists.pdxlinux.org/mailman/listinfo/plug _______________________________________________ PLUG mailing list PLUG@pdxlinux.org http://lists.pdxlinux.org/mailman/listinfo/plug
