How would I remove all text outside single quotes in VIM using regex?

Question

I'm using a vim script to quickly edit some text. I have a large list from an api endpoint that looks like this:

                save:   presets.api + 'campaign/:campaignId/settings',
                accept: presets.api + 'campaign/:campaignId/acceptContractTerms',
                list:   presets.api + 'campaign/:campaignId/helloSignTemplates',
                create: presets.api + 'campaign/:campaignId/helloSignTemplates/create',
                post:   presets.api + 'campaign/:campaignId/helloSignTemplates',
                patch:  presets.api + 'campaign/:campaignId/helloSignTemplates/:templateId',
                delete: presets.api + 'campaign/:campaignId/helloSignTemplates/:templateId',

I'd really like to delete all text that is not inside single quotes. What would the vim regex command for that be?

Answer 1

It's arguably even easier to do this without regular expressions, by using the :normal command. To delete the text on one line you would type: df';D, which deletes to the first quote (df'), moves to the next quote (;), and then deletes the rest of the line (D). So to do this on the entire file with one command, run:

:%norm!df';D

If you wanted to keep the quote marks as well, the command is slightly longer, but just as simple:

:%norm!dt';llD

Answer 2

If it's given that only one single-quoted text will appear in a line, then the regex is simple:

%s:\v.{-}('.{-}').*:\1:

• %s: run :h :substitute over the whole buffer
• :: delimiter
• \v: use :h /magic mode
• pattern to be replaced
  • .{-}: select least-possible characters
  • '(.{-})': select text wrapped in single-quotes and mark it as sub-expression (see :h /\()
  • .*: match any text as many number of times as possible
• :: delimiter
• \1: replace the matched pattern with the first sub-expression (which is the text wrapped in single-quotes.

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This will leave only the first single-quoted text and delete everything else. If two or more single-quoted text exist in a line, this regex will not be functional. We can devise another regex for that case, but since that is slightly more difficult to come up with, I'm leaving it as to-be-done only if the OP expresses they require it.