rather off-topic, but i've noticed quite a few "modern" cli apps do the "--" thing and make it mandatory; am i alone in finding it weird that flag parsing does not automatically stop after the positional argument for a program that expects to accept a command line?
e.g. it's
sudo -E env -v
not
sudo -E -- env -v
or
sudo -E env -- -v
(sudo stops parsing its own flags after 'env', the positional argument).
> The first -- argument that is not an option-argument should be accepted as a delimiter indicating the end of options. Any following arguments should be treated as operands, even if they begin with the '-' character.
> All options should precede operands on the command line.
> If an argument can be identified according to Guidelines 3 through 10 as an option, or as a group of options without option-arguments behind one '-' delimiter, then it should be treated as such.
I think that the rule "all options should precede operands" has been broken so much in practice (particularly since any subcommand must break it) that it may as well not be a rule. And if it's not a rule, then the only way to unambiguously distinguish options from operands-that-start-with-a-dash-but-should-be-passed-verbatim-as-operands... is to require a double-dash.
If they accept only one positional argument, and do not allow flags after it, yeah that definitely seems weird.
Many of these are flag-position-agnostic though, and for that the -- is a very long-time standard pattern for either "end of this command, forward the rest to the wrapped command" or a list of files (to make a file named --help unambiguous).
Many. Definitely not all. CLI interfaces are even more varied than GUIs in many ways.
I believe this originates from GNU argument syntax and is commonly implemented by software supporting GNU-style long options. Terminating after the first argument IIRC is what software implementing BSD style argument parsing usually does. OTOH though, I am sure there is software that implements hybrids of both approaches. I don't think any approach is particularly "weird" really, both of them make perfect sense in isolation.
rather off-topic, but i've noticed quite a few "modern" cli apps do the "--" thing and make it mandatory; am i alone in finding it weird that flag parsing does not automatically stop after the positional argument for a program that expects to accept a command line?
e.g. it's
not or (sudo stops parsing its own flags after 'env', the positional argument).