Allowing command parameters that start with a dash

Recipes & Guides
1

I recently ran in trouble with an

exec "$string"

command executed in a shell expansion, and in which the string started with a dash (-). Even single quotes around the string did not stop Kakoune from interpreting it as an illegal switch to exec and raising an error. Fortunately there is a way around, using two dashes -- to signal switch ending

exec -- "$string"

as in the case of many standard Unix commands. This also works with Kakoune commands that accept switches, such as echo.

I have seen this trick used in a few script examples, but I have not seen it documented anywhere. If I am right about the lack of documentation, then this post with its title may be helpful to Kakoune newcomers.

2

Is it shell exec or kakoune execute-keys?

3

I tested it and I can replicate the same issue with kakoune’s execute-keys. In all these cases, - is interpreted as option prefix:

execute-keys -
execute-keys "-"
execute-keys %{-}

and as it was said in original post, this is the solution that works:

execute-keys -- -
4

I was confused by the shell variable in original post. I was also experncing the same problem once, and didn’t seem any mention of that feature in docks back then

5

Sorry about the confusion, this is indeed Kakoune’s command

execute-keys

I use the exec alias in Kakoune’s shell expansions because the line is more concise, for example:

evaluate-commands %sh{
    sequence_of_keys='-----------------'
    printf '%s' "exec -- $sequence_of_keys"
}

to insert a string of dashes in Insert mode.

But what I said applies to other Kakoune commands that accept switches. For example, typing this at Kakoune’s command prompt:

echo '-hello'

will raise an error:

'echo' unknown option '-hello'

Now try this:

echo -- '-hello'

No error is raised.

6

In my next post I’ll send a short script in which this issue with dashes arose.