Support for nil default value in IP flag

[Maximilan4]

I have some flag definition code in cobra:

listCmd.Flags().IP("ip", nil, "--ip")

And then i running this:

ip, err := flags.GetIP("ip")

I got an error: invalid string being converted to IP address: <nil>
Same result with this definition:

listCmd.Flags().IP("ip", net.IP{}, "--ip")

In my logic, flag is optional, and i dont want to work with net.Parse("0.0.0.0") and string values.

Updated
nil as default value works thought IPVar, but wanna minimize package level variables for each command.

var ip  net.IP
listCmd.Flags().IPVar(&ip, "ip", nil, "--ip")

[lee3164]

I have the same question. some times, I just want to keep some var null when users don't pass args.

[tomasaschan]

This issue has not been updated in a long time. Is it still relevant?

(If I receive no answer before the end of the summer, I'll close it. Feel free to re-open if you come here after that happens and it is relevant to you - but if you do, please also comment and specify what outcome you're interested in!)