[TUHS] Systematic approach to command-line interfaces [ meta issues ]

Bakul Shah bakul at iitbombay.org
Sun Aug 1 08:14:41 AEST 2021

On Jul 31, 2021, at 3:13 PM, Larry McVoy <lm at mcvoy.com> wrote:
> On Sat, Jul 31, 2021 at 03:04:48PM -0700, Bakul Shah wrote:
>> On Jul 31, 2021, at 12:20 PM, Jon Steinhart <jon at fourwinds.com> wrote:
>>> So I never got getopt().  One of my rules is that I don't use a library
>>> in cases where the number of lines of gunk that that it takes to use a
>>> library function is >= the number of lines to just write it myself.  Yeah,
>>> I know the "but the library has more eyeballs and is debugged" argument
>>> but in reality libraries are the source of many bugs.  I've always taken
>>> the approach that I would never hire someone who had to use a library to
>>> implement a singly-linked list.
>> getopt() is perhaps the wrong solution but consider something like MH,
>> whose commands all follow a common pattern. Consider:
>>  - options (switches) all start with a single '-'
>>  - they may be abbreviated to a unique prefix.
> That last one is a gotcha waiting to happen:
> program --this-is-the-long-option
> is the same as 
> program --this
> but that will break scripts (and fingers) when program gets a new 
> option like

That is easy to fix: use full options in scripts. Abbreviations for
interactive use. Much better than --always-having-to-type-long-names.

> program --this-is-the-even-longer-option
> We wrote our own getopt() for BitKeeper and it had long and short options
> but no gotcha unique prefix.

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