How to pass empty string '' to vim.fn.jobstart in cmd parameter ?

[linrongbin16]

Hi, I want to pass this command:

rg --column -n --no-heading --color=always -S -- ''

to vim.fn.jobstart(cmd, {...}) API, but it fails.

It seems it's because the last empty string '' cannot been evaluate correctly, is there anything I could do for this???

device info:
OS: macOS M1 MAX, 13.5
Neovim: v0.9.1 Release, LuaJIT 2.1.0-beta3

[zeertzjq]

Repeat each single quote twice.

[linrongbin16]

hi @zeertzjq, is there any document about the reason? (I just want to learn it, because I want to write a script to dynamically pass user input to terminal inside nvim)

In my knowledge, I think I should pass '\'\'' or "''" to cmd, because the single quotes inside a string should prepend with a backslash? is that correct or wrong?

[zeertzjq]

:h literal-string

[linrongbin16]

Hi @zeertzjq , I tried to use list instead of string:

This is the lua code:

local jobid = vim.fn.jobstart(
    { "rg", "--column", "-n", "--no-heading", "--color=always", "-S", "--", "''" },
    {
        on_stdout = function(chanid, data, name)
            print("stdout, data:" .. vim.inspect(data))
        end,
        on_stderr = function(chanid, data, name)
            print("stderr, data:" .. vim.inspect(data))
        end,
        on_exit = function(id, exitcode, event)
            print("exit, exitcode:" .. vim.inspect(exitcode))
        end,
    }
)
vim.fn.jobwait({ jobid })

But it still not working, I add some print in the on_stdout, on_stderr and on_exit, but none of them really prints.

[linrongbin16]

While I found lua's io.execute(cmd) could work correctly (when the cmd is a string), there's no need to deal with escaping characters.

But lua io cannot handle async IO, I want faster respond on_stdout to processing the command output when running command on big code base.

[linrongbin16]

I finally use the lua io.popen to solve this:

share the lua code:

local f = io.popen("rg --column -n --no-heading --color=always -S -- ''")
for line in f:lines("*line") do
   -- processing each line from stdout
end
f:close()