Document external_subcommand

[tanj]

I'm trying to solve a problem in pyflow where we have a subcommand that is supposed to execute a python script. I'm trying to solve a bug where you can't pass command line options to the script we are trying to run. It looks like I should use external_subcommand to do that, but I'm not seeing a way to document the supported "external" commands.

Ideally they should show up in the list of subcommands. Is there a way to do this?

[TeXitoi]

Sorry, but I can't help you with such a bug report. You need to be more precise: what did you try? Why it doesn't work? What do you expect?

Ideally, a minimal compiling program that do about what you want, with the explanation of what doesn't work, will allow me to understand your problem, and probably help you fixing it.

[tanj]

// main.rs
use structopt::StructOpt;

#[derive(Debug, PartialEq, StructOpt)]
#[structopt(name = "clitest", about = "demonstration for bug report")]
struct Opt {
    #[structopt(subcommand)]
    sub: Subcommands,
}

#[derive(Debug, PartialEq, StructOpt)]
enum Subcommands {
    /// Add subcommand
    Add,

    // `external_subcommand` tells structopt to put
    // all the extra arguments into this Vec
    /// Document for external sub commands:
    /// run  <SCRIPT> [script options]  Run the script with it's options
    #[structopt(external_subcommand)]
    Other(Vec<String>),
}

fn main() {
    let _opt = Opt::from_args();
}

Output of program.

$ ./target/debug/cli-so.exe --help
clitest 0.1.0
demonstration for bug report

USAGE:
    cli-so.exe <SUBCOMMAND>

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information

SUBCOMMANDS:
    add     Add subcommand
    help    Prints this message or the help of the given subcommand(s)

I would expect it would be possible to add documentation for the external_subcommand to have it print with the help message. Ideally it would be listed with the existing SUBCOMMANDS: list

[tanj]

I found a way to work around this.

Adding a trailing space to the structopt name allows the documentation to be displayed and the option to never be picked up on the command line.

// main.rs
use structopt::StructOpt;

#[derive(Debug, PartialEq, StructOpt)]
#[structopt(name = "clitest", about = "demonstration for bug report")]
struct Opt {
    #[structopt(subcommand)]
    sub: Subcommands,
}

#[derive(Debug, PartialEq, StructOpt)]
enum Subcommands {
    /// Add subcommand
    Add,
    /// Fake script documentation
    #[structopt(name = "script ")]
    Script,

    // `external_subcommand` tells structopt to put
    // all the extra arguments into this Vec
    /// Document for external sub commands:
    /// run  <SCRIPT> [script options]  Run the script with it's options
    #[structopt(external_subcommand)]
    Other(Vec<String>),
}

fn main() {
    let _opt = Opt::from_args();
    eprintln!("opts: {:?}", opt);
}

Help output becomes:

$ ./target/debug/cli-so.exe --help
clitest 0.1.0
demonstration for bug report

USAGE:
    cli-so.exe <SUBCOMMAND>

FLAGS:
    -h, --help       Prints help information
    -V, --version    Prints version information

SUBCOMMANDS:
    add        Add subcommand
    help       Prints this message or the help of the given subcommand(s)
    script     Fake script documentation

output with my external script command

 % ./target/debug/cli-so.exe script --other --args and values
opts: Opt { sub: External(["script", "--other", "--args", "and", "values"]) }

[TeXitoi]

I'm not sure I understand exactly what you want, but I'll do that:

use structopt::StructOpt;

#[derive(Debug, PartialEq, StructOpt)]
#[structopt(name = "clitest", about = "demonstration for bug report")]
struct Opt {
    #[structopt(subcommand)]
    sub: Subcommands,
}

#[derive(Debug, PartialEq, StructOpt)]
enum Subcommands {
    /// Add subcommand
    Add,

    /// Document for external sub commands:
    /// run  <SCRIPT> [script options]  Run the script with it's options
    #[structopt(setting = structopt::clap::AppSettings::TrailingVarArg)]
    Run { args: Vec<String> },
}

fn main() {
    let opt = Opt::from_args();
    println!("{:?}", opt);
}

[TeXitoi]

Closing as I can't do more, feel free to reopen and explaining what's wrong if there is still a problem.