Implement GET NUMLOGINS

Fixes #11

nut-client/examples/async.rs

@@ -35,6 +35,10 @@ async fn main() -> nut_client::Result<()> {
     for (name, description) in conn.list_ups().await? {
         println!("\t- Name: {}", name);
         println!("\t  Description: {}", description);
+        println!(
+            "\t  Number of logins: {}",
+            conn.get_num_logins(&name).await?
+        );
 
         // Get list of mutable variables
         let mutable_vars = conn.list_mutable_vars(&name).await?;

nut-client/examples/blocking.rs

@@ -34,6 +34,7 @@ fn main() -> nut_client::Result<()> {
     for (name, description) in conn.list_ups()? {
         println!("\t- Name: {}", name);
         println!("\t  Description: {}", description);
+        println!("\t  Number of logins: {}", conn.get_num_logins(&name)?);
 
         // Get list of mutable variables
         let mutable_vars = conn.list_mutable_vars(&name)?;

nut-client/src/cmd.rs

@@ -92,6 +92,10 @@ pub enum Response {
     ///
     /// Params: (variable description)
     Desc(String),
+    /// A NUMLOGINS response.
+    ///
+    /// Params (number of logins)
+    NumLogins(i32),
 }
 
 impl Response {
@@ -301,6 +305,28 @@ impl Response {
                 }?;
                 Ok(Response::Desc(desc))
             }
+            "NUMLOGINS" => {
+                let _device = if args.is_empty() {
+                    Err(ClientError::from(NutError::Generic(
+                        "Unspecified NUMLOGINS device in response".into(),
+                    )))
+                } else {
+                    Ok(args.remove(0))
+                }?;
+                let num = if args.is_empty() {
+                    Err(ClientError::from(NutError::Generic(
+                        "Unspecified NUMLOGINS number in response".into(),
+                    )))
+                } else {
+                    Ok(args.remove(0))
+                }?;
+                let num = num.parse::<i32>().map_err(|_| {
+                    ClientError::from(NutError::Generic(
+                        "Invalid NUMLOGINS number in response".into(),
+                    ))
+                })?;
+                Ok(Response::NumLogins(num))
+            }
             _ => Err(NutError::UnknownResponseType(cmd_name).into()),
         }
     }
@@ -380,6 +406,14 @@ impl Response {
             Err(NutError::UnexpectedResponse.into())
         }
     }
+
+    pub fn expect_numlogins(&self) -> crate::Result<i32> {
+        if let Self::NumLogins(num) = &self {
+            Ok(*num)
+        } else {
+            Err(NutError::UnexpectedResponse.into())
+        }
+    }
 }
 
 /// A macro for implementing `LIST` commands.
@@ -645,6 +679,14 @@ implement_get_commands! {
             { |row: Response| row.expect_cmddesc() },
         )
     }
+
+    /// Queries the number of logins to the specified UPS.
+    pub fn get_num_logins(ups_name: &str) -> i32 {
+        (
+            { &["NUMLOGINS", ups_name] },
+            { |row: Response| row.expect_numlogins() },
+        )
+    }
 }
 
 implement_simple_commands! {