JEP 293: Guidelines for JDK Command-Line Tool Options
jonathan.gibbons at oracle.com
Fri Jul 8 14:01:27 UTC 2016
On 07/07/2016 11:07 PM, Dan Smith wrote:
> A suggestion for clarifying the text: I was confused about whether "may" refers to choices that the tool developer is allowed to make, or choices that the end user is allowed to make.
> For example: "Options can require an argument to be provided. For a long-form options, the argument may be separated from the option name by either white space or '='."
> Is the idea that the tool should support '=' as an alias for white space, or that the tool choose which form it wants to support? I'm guessing the latter, but I'm not totally confident in that guess.
It means that, as you put it, "=" is an alias for white-space, so that
you can use either of the following forms:
Although it is typically easier to use and read the whitespace form, the
'=' form is often more convenient when using the option in context where
whitespace has conflicting significance. For example, contrast the
following two ways of setting the module path of javac's runtime
environment (OK, it's a contrived example, but you get the point)
javac ... -J--module-path -Jmy:module:path ...
javac ... -J--module-path=my:module:path ...
Other, more realistic, examples that would require more setup to
illustrate, would be in situations like shell scripts where you might
need to take the shell's rules for white space expansion into account.
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