What should Python apps do when asked to show help?

[alister]

On Sun, 01 May 2016 17:28:53 +1000, cs wrote:

> On 01May2016 16:44, Chris Angelico <rosuav at gmail.com> wrote:
>>On Sun, May 1, 2016 at 3:24 PM,  <cs at zip.com.au> wrote:
>>> Yes, PAGER=cat would make "man" also not page, and likely almost
>>> everything.
>>> And yet I am unwilling to do so. Why?
>>>
>>> On reflection, my personal problems with this approach are twofold:
>>>
>>> - I want $PAGER to specify my preferred pager when I do want a pager,
>>> so setting it to "cat" does not inform apps about my wishes
>>
>>So you expect the environment variable to say which of multiple pagers
>>you might want, but only when you already want a pager. Okay. How is an
>>app supposed to know whether or not to use a pager? How do you expect
>>them to mindread?
> 
> I think for several of us, we do not expect the app to mindread. Don't
> page for short output!
> 
> As the rest of my article remarks, I at least think "man" should page on
> the premise than manual pages will be long enough to benefit, as they
> should be.
> 
> Aside: especially if one uses "less" and includes the -d and -F options
> in the $LESS envvar, which suppresses the warning about "dumb" terminals
> and autoquits if the file fits on the screen - these two provide most of
> the painfree behaviour for short outputs and embedded ttys at least.
> 
> We could fork a separate discussion on making pagers more seamless, and
> terminal emulators with nice modes to reduce the need for pagers.
> 
> Cheers,
> Cameron Simpson <cs at zip.com.au>

all the discussion on the pager variable is interesting but it overlooks 
what I consider to be a very important lesson on program output.

You have no way of knowing what the users output device is & have no 
right to dictate what that should be.

alternative outputs for the command line could be.

a teletype printer 
a text to speech reader
a Braille terminal
or a computer to (dead) parrot) interface

which is why mot of us here all agree, just output the data, let the end 
users environment decide how to present it, that is the users choice not 
the programmers.




-- 
Get in touch with your feelings of hostility against the dying light.
		-- Dylan Thomas [paraphrased periphrastically]