Re: [pbs-devel] [PATCH proxmox] router: cli: added `ask_for_confirmation` helper

[Gabriel Goller <g.goller@proxmox.com>]

On 9/7/23 17:26, Thomas Lamprecht wrote:
> On 30/08/2023 14:45, Gabriel Goller wrote:
>> Added `ask_for_confirmation` helper that outputs a prompt and
>> lets the user confirm or deny it. Implemented to close #4763.
>>
>> Signed-off-by: Gabriel Goller <g.goller@proxmox.com>
>> ---
>>
>> Note: A dependency bump is needed.
>>
>>   proxmox-router/src/cli/mod.rs | 19 ++++++++++++++++++-
>>   1 file changed, 18 insertions(+), 1 deletion(-)
>>
>> diff --git a/proxmox-router/src/cli/mod.rs b/proxmox-router/src/cli/mod.rs
>> index 208df4a..2366b47 100644
>> --- a/proxmox-router/src/cli/mod.rs
>> +++ b/proxmox-router/src/cli/mod.rs
>> @@ -12,11 +12,15 @@
>>   //! - Ability to create interactive commands (using ``rustyline``)
>>   //! - Supports complex/nested commands
>>   
>> -use std::collections::HashMap;
>> +use std::{
>> +    collections::HashMap,
>> +    io::{self, Write},
>> +};
>>   
>>   use crate::ApiMethod;
>>   
>>   mod environment;
>> +use anyhow::bail;
> hmm, anyhow on library code is a slight smell, not sure about our verdict
> here, for API stuff it's widely used anyway – @Wolfgang (or @Max, you checked
> out error handling too here IIRC)
Discussed with Max, decided to use `io:Error`.
>>   pub use environment::*;
>>   
>>   mod shellword;
>> @@ -62,6 +66,19 @@ pub fn init_cli_logger(env_var_name: &str, default_log_level: &str) {
>>       .init();
>>   }
>>   
>> +pub fn ask_for_confirmation(query: String) -> Result<(), anyhow::Error> {
>> +    print!("{} [y/N]: ", query);
> here too w.r.t. format strings and params please:
>
> "{query} [y/N]"
>
>> +    io::stdout().flush()?;
>> +    let stdin = io::stdin();
>> +    let mut line = String::new();
>> +    stdin.read_line(&mut line)?;
> don't we have already some pty/tty helpers that we use for passwords that
> we could re-use here? Not a hard recommendation or the like, just interest.
We only have a helper for the tty output (`TtyOutput`), which is used to
write the asterisks for the password input. I don't think this is useful 
in this case.
>> +    if line.trim() == "y" {
> Hmm, not locale-aware though. Albeit we do not place that much of an
> emphasis on being so in our CLI tools.
>
> Would be rather just interesting if there are sane wrappers or
> implementations for something like nl_langinfo's [0] YESEXPR or NOEXPR
> fom libc in rust.
>
> [0]: https://manpages.debian.org/bookworm/manpages-dev/nl_langinfo.3.en.html
Yes, this is nice. I will use `YESEXPR` to match the input from the cli. To
show a localized prompt (the [y/n] thing) I'll extract the lowercase 
character
from the `YESEXPR` and `NOEXPR` (Which is a bit hacky, but sadly the
`NOSTR` and `YESSTR` parameter are deprecated :( ).
> Anyhow, not blocking this, just stuck out – would at least compare
> the char case-insensitive though.
>> +        Ok(())
>> +    } else {
>> +        bail!("Aborted");
>> +    }
>> +}
>> +
>>   /// Define a simple CLI command.
>>   pub struct CliCommand {
>>       /// The Schema definition.