Make it easier to use --multiline-dotall

[waldyrious]

What version of ripgrep are you using?

❯ rg --version
ripgrep 11.0.2
-SIMD -AVX (compiled)
+SIMD +AVX (runtime)

How did you install ripgrep?

brew install ripgrep

What operating system are you using ripgrep on?

MacOS Catalina (v10.15.2)

Describe your question, feature request, or bug.

I often need to search for patterns that span multiple lines, for which the combination --multiline --multiline-dotall is very helpful. There are two changes that would make this feature less cumbersome to use, though:

1. Passing --multiline-dotall could automatically assume --multiline;
2. A short option name could be added for --multiline-dotall, just like there's -U for --multiline.

These two together would make a command like

rg -U --multiline-dotall 'foo.+?bar'

become, say:

rg -µ 'foo.+?bar'

(of course, replacing -µ with the actual short option name for --multiline-dotall).

Alternatively, if only (2) is implemented, it would still be quite more convenient:

rg -Uµ 'foo.+?bar'

I'd be happy to submit a PR if this is something that would be welcome.

[BurntSushi]

Thanks for the thoughtful issue. I have a few thoughts.

I think making --multiline-dotall enable --multiline sounds plausible to me on the surface. However, the original intent was that folks could put --multiline-dotall in their config file (or alias), which would be inert without --multiline but otherwise enable the dotall behavior by default when --multiline is used. This is indeed a documented behavior, so I'm hesitant to change it. This may work for you if --multiline-dotall is indeed the most common thing. You could then use --no-multiline-dotall or (?-s) to disable it in the few cases where you don't want it.

Additionally, --multiline-dotall is not the only way to enable this behavior. For example, instead of

$ rg -U --multiline-dotall 'foo.+?bar'

you could write

$ rg -U '(?s)foo.+?bar'

Finally, the problem with using a short option is that we have very few choices left and I'm not quite sure this rises to the level of needing that. Especially when (?s) works and is fairly short on its own, although perhaps a bit more awkward to type than a short flag.

[waldyrious]

Thanks for the incredibly fast and detailed response!

Indeed I was reading through similar issues (especially the very informative #1150!) and realized that (?s) could be used as a somewhat more convenient alternative to spelling out --multiline-dotall. Not nearly as convenient as a single-letter option, but as you say, with the flag in the pattern itself and the config file method both being available, it may be hard to justify eating up yet another single-letter option.

Just to add a bit more concrete context: in order to type rg -U '(?s)foo.+?bar' I need 26 key-presses in my Portuguese keyboard layout, including modifiers like Shift:

• r, g, ␣, -, Shift+u, ␣, ', Shift+8, Shift+', s, Shift+9, f, o, o, ., +, Shift+', b, a, r, '

...while for rg -µ 'foo.+?bar' (assuming, again, that µ would become a plain ASCII letter), I would only need 18 (19 at worst, if it's uppercase):

• r, g, ␣, -, µ, ␣, ', f, o, o, ., +, Shift+', b, a, r, '

That said, I would be OK with this issue being closed, but I'd suggest keeping this open for a while to gauge community interest. It may be that the trade-off is indeed worth if many people would support it.

ps - I will make sure to include some reference to the above options in ripgrep's tldr page to make this more discoverable.