How to use two parameters at the same time but only need one parameter to have a value

[bin-ly]

Hello, I want to use clap to define two parameters, such as -a parameter and -b parameter. These two parameters can be used at the same time or separately. For example, used at the same time: -a -b test.txt;
Use alone: ​​-a test.txt; -b test.txt

The problem I am currently encountering is that when the -a parameter and the -b parameter are used at the same time, both parameters must have a value. But I hope that when these two parameters are used at the same time, I only need the -b parameter to have a value.

[epage]

First off, I would say that CLI pattern you are trying to create is a bit of an oddball and I would recommend seriously reconsidering if it is the right design.

That said, you could mark the arguments with num_args = 0..=1. This would put enforcement that one of them must have a value within your application.

[epage]

From that usage, it looks like the model is

• hostname and -F file form a group with multiple=false
• -b requires the above group
• The display format flags form a group that conflicts with the above group

[bin-ly]

I still don't quite understand how to do it. I hope that when the -b parameter and the -F parameter are used together, the -b parameter does not need to have a value, like in the picture above: "hostname -b -F ..."

[bin-ly]

"hostname" here is the command, "-b" and "-F" are parameters, and the values ​​they follow are string types.

[bin-ly]

Or can parameters of type Option have no value? Similar to bool type

[epage]

I'm talking about something like

#[derive(Parser)]
struct HostnameArgs {
    #[command(flatten)]
    set: Option<SetArgs>,
    #[command(flatten)]
    get: Option<GetArgs>,

    #[arg(short, long, requires = "SetArgs")]
    boot: bool,
}

#[derive(Args)]
#[group(conflicts_with = "GetArgs")]
#[group(multiple = false)]
struct SetArgs {
    #[arg(short = 'F', long)]
    file: Option<std::path::PathBuf>,

    hostname: Option<String>
}

#[derive(Args)]
struct GetArgs {
    #[arg(short, long)]
    alias: bool,

    #[arg(short = 'A', long)]
    all_fqdns: bool,

    #[arg(short, long)]
    domain: bool,

    #[arg(short, long, visible_alias = "long")]
    fqdn: bool,

    #[arg(short, long)]
    ip-address: bool,

    #[arg(short = 'I', long)]
    all-ip-addresses: bool,

    #[arg(short, long)]
    short: bool,

    #[arg(short, long, visible_alias = "nis")]
    yp: bool,
}