Many tools, for consistency or for laziness always print usage to stderr. But it is better than always printing it to stdout. Errors should never go to stdout, and paging stderr can easily be done with 2>&1.
Edit: and maybe, if your --help output is several pages long, consider leaving out the details to a manpage.
But it's also really useful to be able to get full synopsis of all the options even if all you have available is the binary. Some programs have a lot of options. The "--help" output for rsync on my machine is 184 lines, and is actually pretty terse.
... and there truly is no agreed-upon idea of what constitutes a "page". Even the VT100 screen size was never dominant enough to always count. And nowadays people's windows may be of almost any size.
But yeah, agree. It's way more preferable to have surprise output on stderr than surprises mingling with stdout, and it's good to be prepared for that.
Frankly, I nearly quit piping to a pager when GUI terminal backscroll became easy and infinite.
80x25
> I set all my terminals to 22x23.
You are a very silly man and silliness should not be catered for.
> Will --help run a few quick ioctls to calculate screen size?
Your terminal can wrap text around just fine. If it can't, ask for refund.
Also my father produced tonnes of scratch paper in narrow strips. I found a way to weave them into a perpetually-growing "tractor-feed snake" which I placed in a padded crib and brought to grade school to show off. I would typically juggle a few bits and bobs to attract even more attention...
I'm sure you could dig around into my hometown's landfill for awhile. They're only 30 years sediment. I'll send you a tarp, shovel, duct tape to stick the pages back together, and my sister's old clothes to wear while you work. DM for deets.
tool [args] 2>&1 | less
Alternatively, tools could build in pagers for fewer pipeline surprises, like the all-encompassing systemd.
Even better, I could envision a framework where any tool that produces output can be automatically subject to pagination, with auto terminal detection and the whole bit. Think of libreadline but for output. You could thereby eliminate plenty of ad hoc hacks.
tool 2>&1 | less
tool |& less $ /bin/bash --version
GNU bash, version 3.2.57(1)-release (x86_64-apple-darwin21)
In that same vein, I wondered if that syntax was supported in zsh since modern macOS went whole hog and ... I gained one more pebble on the huge pile of steaming turds why I detest zsh
$ /bin/zsh -exc '{ echo alpha; echo beta; } |& wc -l'
+zsh:1> wc -l
4
$ /bin/zsh -exc '{ echo alpha; echo beta; } |& cat'
+zsh:1> cat
+zsh:1> echo alpha
alpha
+zsh:1> echo beta
beta
XTRACE (-x, ksh: -x)
Print commands and their arguments as they are executed.
-x is the most invaluable tool in my shell-debugging toolkit. It is great to see every command evaluated and run alongside the script output itself. I use it multiple times per day at work.