On 17 May 12:50, G. Branden Robinson wrote: > [looping in linux-man@ because issues of user education and topics that > fall between project/man page stools come up below] > > At 2021-05-16T20:29:30-0500, Dave Kemper wrote: > > This stuff about less(1) is only tangential to groff, but it did come > > up in the context of viewing man pages, so I'm keeping the groff list > > in the cc. > > Good idea. I've further changed the Subject: to reflect the flow of the > discussion. > > > On 5/12/21, G. Branden Robinson <g.branden.robin...@gmail.com> wrote: > > > One thing I would mention is that less(1) supports regex searches > > > within its buffer. On my system, the searches are even > > > case-insensitive by default if the search pattern is all lowercase, > > > and not otherwise. > > > > less's default is for searches to be case-sensitive. Its -i option > > (which can be given on the command line or while less is running) is > > what activates the behavior described above. A user or a distro might > > make -i the default in their environment (I do) through the $LESS > > environment variable or an alias, but that isn't less's out-of-the-box > > behavior. > > On my Debian buster-based system, less(1) behaves that way, but $LESS is > not defined in my environment and I don't have a shell alias or function > set up. Checking the source package, I don't see patches to turn -i on > by default. Baffling!
man(1) from the man-db package execs less(1) (or other configured pager) with the LESS environment variable populated with "-ix8RmPm%s$PM%s$". The %s escapes are replaced by the prompt string. See include/manconfig.h: #define LESS_OPTS "-ix8RmPm%s$PM%s$" Any existing $LESS is appended to this string prior to exec, allowing these options to be overridden. This is on debian buster. > > > > In fact, to leap among sections you can do > > > > > > /^[a-z] > > > > > > regardless of the lettercase convention, and after doing the above > > > once you can type simply > > > > > > / > > > > > > to repeat the search or > > > > > > ? > > > > > > to repeat it in the backwards direction. > > > > Or to save yourself a keypress (since those methods require a "Return" > > after the "/" or "?") you can use "n" and "N" respectively. Longtime > > vi users will do this without even thinking about it. > > Yup, you caught me. :D > > I don't think it's ever too soon to teach a user who has seen man pages > how to get more out of them, and that includes the pager interface. > It's frustrating because man(1), less(1), and man(7), formally > considered, can all disclaim responsibility for communicating this > knowledge. less(1) can page all sorts of text files, not just man > pages, and its own man page is huge and talks about all kinds of stuff. > man(1) is also big, and that program definitely is not the pager. > man(7) documents the macro package[1], which is a man page _writer's_ > interface, not primarily one for the reader. > > I find myself wishing that intro(1) from the Linux man-pages project > said more about this, either directly in that page or maybe in the > man(7) they provide, with a conspicuous pointer there from the former. > > Maybe Michael or Alejandro can advise regarding where they think a good > place for a man page utilization tutorial would be. > > I also wonder if the pager wars are basically over and less(1) won them. > I haven't heard anyone mention most(1) in a long time[2], and the, uh, > simple elegance of more(1)'s inability to seek its stream (meaning: no > backwards searching) seems to have driven many people to less(1) even if > they have reservations about the length of its feature list. > > Regards, > Branden > > [1] Michael Kerrisk can correct me, I hope, but as far as I know the > Linux man-pages man(7) page arose because, back in the '90s, the GNU > roff project refused to supply one, in keeping with the GNU "no > documentation at all if not Texinfo" philosophy--Susan G. Kleinmann > of Debian had to write one, which I guess escaped the notice of the > (Red Hat-using?) man-pages maintainer(s) of the time. By 1999, the > rigor of groff's fealty to that principle had slackened, and, > judging by groff's CVS-to-Git history, it looks like I can credit > Werner Lemberg with adopting and revising her work as groff_man(7). > > [2] a fate that seems to have inexorably claimed any project that > hitched its horses to S-Lang's wagon
