I'd like to parse ipv4 addresses given as command line argument values.
I have got two arguments accepting ipv4 address.
If I specify single such option all is fine.
If I specify both, I 'm getting error like this:
thread 'main' (624061) panicked at /home/peto/.cargo/registry/src/index.crates.io-1949cf8c6b5b557f/clap-3.2.25/src/parser/matches/arg_matches.rs:1879:13:
Must use `Arg::allow_invalid_utf8` with `_os` lookups at `[hash: A8F400C40154F09]`
This is simplified version of my code showcasing the issue:
```
use std::net::{IpAddr, Ipv4Addr};
use clap::{App, AppSettings, Arg, value_parser};
#[tokio::main]
async fn main() -> Result<(), Error> {
let mut app = App::new("Server APP")
.about("My super cool app")
.setting(AppSettings::DeriveDisplayOrder)
.setting(AppSettings::SubcommandsNegateReqs)
.arg(
Arg::with_name("socket")
.required(true)
.takes_value(true)
.long("socket")
.help("Unix socket path"),
)
.arg(
Arg::with_name("relayaddress")
.required(false)
.takes_value(true)
.long("relay-address")
.value_parser(value_parser!(Ipv4Addr))
.help("External relay ipv4 address used together with --listen-address to run behind a nat"),
)
.arg(
Arg::with_name("listenaddress")
.required(false)
.takes_value(true)
.long("listen-address")
.value_parser(value_parser!(Ipv4Addr))
.help("Local listen ipv4 address used together with --relay-address to run behind a nat"),
);
let matches = app.clone().get_matches();
if matches.is_present("relayaddress") & matches.is_present("listenaddress") {
let external_ip = IpAddr::V4(matches.get_one::<Ipv4Addr>("relayaddress").expect("Invalid address"));
let local_ip = IpAddr::V4(matches.get_one::<Ipv4Addr>("listenaddress").expect("Invalid address"));
println!("Listening on local IP: {local_ip}");
println!("Relaying through external IP: {external_ip}");
}}
```
#rust #rustlang #programming #fedihelp
![Screenshot of an excerpt from Section 5, Discussion:
In response to the research questions posed in Section II, we find that identifier style significantly affects time and visual effort needed to correctly detect identifiers constructed from a phrase. The underscore style is significantly faster and positively influences the dependent variables. In the Binkley et al. study [4], Phrase Length did not interact with Style, however we find such an interaction in our analysis. The common theme in both experiments is that camel-cased identifiers take longer than underscored ones (13.5% in the previous study and 20% in this study) overall. In the Binkley et al. study, higher accuracy was found for camel-cased identifiers, however, in our study, all (except one) subjects answered correctly on all questions making accuracy comparisons irrelevant.
In our study, no interaction effects were found between the Experience secondary factor and the independent variable Style. The previous study found Training (vis-à-vis Experience in our study) to significantly interact with Style affecting the time to find an identifier. Their findings indicate that subjects trained in the camel-case style take less time to identify a camel-cased identifier than an underscore identifier.](https://fedi.ml/photo/preview/640/684070 "Screenshot of an excerpt from Section 5, Discussion:
In response to the research questions posed in Section II, we find that identifier style significantly affects time and visual effort needed to correctly detect identifiers constructed from a phrase. The underscore style is significantly faster and positively influences the dependent variables. In the Binkley et al. study [4], Phrase Length did not interact with Style, however we find such an interaction in our analysis. The common theme in both experiments is that camel-cased identifiers take longer than underscored ones (13.5% in the previous study and 20% in this study) overall. In the Binkley et al. study, higher accuracy was found for camel-cased identifiers, however, in our study, all (except one) subjects answered correctly on all questions making accuracy comparisons irrelevant.
In our study, no interaction effects were found between the Experience secondary factor and the independent variable Style. The previous study found Training (vis-à-vis Experience in our study) to significantly interact with Style affecting the time to find an identifier. Their findings indicate that subjects trained in the camel-case style take less time to identify a camel-cased identifier than an underscore identifier.")
