clap does not split arguments seperated by a backslash

[hbina]

Trying to fix an issue in this PR for uutils.

PS C:\Users\Hanif\git\uutils> cargo run -- tr '\x\' 'x'
   Compiling uu_tr v0.0.7 (C:\Users\Hanif\git\uutils\src\uu\tr)
   Compiling coreutils v0.0.7 (C:\Users\Hanif\git\uutils)
    Finished dev [unoptimized + debuginfo] target(s) in 3.71s
     Running `target\debug\coreutils.exe tr \x\ x`
clap_arg:"\\x\\ x"
std env args:["target\\debug\\coreutils.exe", "tr", "\\x\\", "x"]
tr: missing operand after '\x\ x'
Try 'tr --help' for more information.
error: process didn't exit successfully: `target\debug\coreutils.exe tr \x\ x` (exit code: 1)

As you can see, as pure args, they are separated, which to me means that windows does not do anything weird with it.
But, as clap's values, they are merged into one.
Strangely, this only happens in Windows.
Is this behavior documented? If so I apologize.

This is how i print them,

let sets = matches
    .values_of(options::SETS)
    .map(|v| {
        v.map(ToString::to_string)
            .inspect(|f| println!("clap_arg:{:?}", f))
            .map(convert::reduce_octal_to_char)
            .collect::<Vec<_>>()
    })
    .unwrap_or_default();
// ...
let args: Vec<String> = std::env::args().collect();
println!("std env args:{:?}", args);

[epage]

clap is using args_os, which args calls into. I'm not seeing any significant platform conditions.

It might be good to run with the debug feature flag and report the output of that. I'm hoping that collects enough data to show whats going on here.

[epage]

I was testing on cmd.exe. So far, it seems like clap is processing what its been given which also makes me wonder about uucore::Args (which is just a wrapper around wild::Args?)

[miDeb]

So far, it seems like clap is processing what its been given which also makes me wonder about uucore::Args (which is just a wrapper around wild::Args?)

Yes. To collect all args we call collect_str which handles invalid utf8 but I doubt it's relevant.

I was testing on cmd.exe.

If I interpret the PS correctly hbina might be using powershell.

[epage]

With powershell

> cargo run -- '\x\' 'x'
warning: unused variable: `code`
 --> src\main.rs:6:9
  |
6 |     let code = uumain(uucore::args_os());
  |         ^^^^ help: if this is intentional, prefix it with an underscore: `_code`
  |
  = note: `#[warn(unused_variables)]` on by default

warning: Error finalizing incremental compilation session directory `\\?\C:\Users\epage\Documents\src\clap-bug\target\debug\incremental\clap_bug-szrpcspkmo4x\s-g169kvzceb-1rkvlty-working`: Access is denied. (os error 5)

warning: 2 warnings emitted

    Finished dev [unoptimized + debuginfo] target(s) in 2.16s
     Running `target\debug\clap-bug.exe \x\ x`
[src\main.rs:5] uuargs = [
    "target\\debug\\clap-bug.exe",
    "\\x\\ x",
]
[src\main.rs:65] std_args = [
    "target\\debug\\clap-bug.exe",
    "\\x\\",
    "x",
]
[src\main.rs:69] sets = Some(
    Values {
        iter: Map {
            iter: Iter(
                [
                    "\\x\\ x",
                ],
            ),
        },
    },
)

So it looks like whatever preprocessing is going on is what is causing the problem.

[hbina]

So what is your assessment of this? Is it wont fix? I dont see how its Powershell mistake because we already received the args as separate characters?

[epage]

The data being passed to clap is incorrect (see the "uuargs" vs "std_args" in the output above). I'd recommend debugging how you are using wild to narrow down if the bug is in that crate.