get exit status from system() call

Question

Calling the function system("<command>") or systemlist("<command>") retrieves the stdout output from a shell call to <command>. How can I retrieve the exit status of that command?

For example, I would like to do something like this:

let output =  system_call_with_exit_status("my_shell_command")
let stdout = output[0]
let exit_status = output[1]
if (exit_status != 0)
    echo output
endif

The intention is to print the output from my_shell_command only if the command gives a non-zero exit status.

Answer 1

Mentioned in the comments above, the v:shell_error variable gives the result of the last shell command. So the exit status can be tested as follows:

let output = system("my_shell_command")
if v:shell_error != 0
    echo output
endif

Answer 2

If you use Lua, the following utility function also helps:

function shell_error()
  return vim.v.shell_error ~= 0
end