add KDGETLED subcommand to vtcol-bin

Actually we add both subcommand and sub-subcommand.

Example:

    [*] 15:52:40 phg@acheron vtcol $ vtcol leds get
    Caps: false, Num: true, Scroll: false

2 files changed, 86 insertions, 2 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 681177c..2ef43e8 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -165,7 +165,7 @@ pub struct KbLedState(u8);
 
 impl KbLedState
 {
-    fn new(cap: bool, num: bool, scr: bool) -> Self
+    pub fn new(cap: bool, num: bool, scr: bool) -> Self
     {
         let mut state = 0u8;
 
@@ -175,6 +175,32 @@ impl KbLedState
 
         Self(state)
     }
+
+    #[inline]
+    pub fn get(con: &Console) -> io::Result<Self> { ioctl::kdgetled(con) }
+
+    #[inline]
+    pub fn cap(&self) -> bool { (self.0 & 0x4) != 0 }
+
+    #[inline]
+    pub fn num(&self) -> bool { (self.0 & 0x2) != 0 }
+
+    #[inline]
+    pub fn scr(&self) -> bool { (self.0 & 0x1) != 0 }
+}
+
+impl fmt::Display for KbLedState
+{
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result
+    {
+        write!(
+            f,
+            "caps: {}, num: {}, scroll: {}",
+            self.cap(),
+            self.num(),
+            self.scr()
+        )
+    }
 }
 
 impl From<libc::c_char> for KbLedState
diff --git a/src/vtcol.rs b/src/vtcol.rs
index c879641..99846be 100644
--- a/src/vtcol.rs
+++ b/src/vtcol.rs
@@ -1,6 +1,6 @@
 pub mod lib;
 
-use vtcol::{Console, Fade, Palette, Scheme};
+use vtcol::{Console, Fade, KbLedState, Palette, Scheme};
 
 use anyhow::{anyhow, Result};
 use std::{io::{self, BufWriter},
@@ -21,6 +21,13 @@ macro_rules! vrb {
 /* struct Job -- Runtime parameters.
  */
 #[derive(Debug)]
+enum LedJob
+{
+    Get(bool),
+    Set,
+}
+
+#[derive(Debug)]
 enum Job
 {
     /** List available schemes. */
@@ -35,6 +42,8 @@ enum Job
     Toggle(Scheme, Scheme),
     /** Fade from current scheme to another. */
     Fade(Option<Scheme>, Scheme, Duration, u8, bool),
+    /** Keyboard LED ops. */
+    Leds(LedJob),
 }
 
 impl<'a> Job
@@ -170,6 +179,22 @@ impl<'a> Job
                             .takes_value(true),
                     ),
             )
+            .subcommand(
+                SubCommand::with_name("leds")
+                    .about("operations regarding keyboard LEDs")
+                    .subcommand(
+                        SubCommand::with_name("get")
+                            .about("get keyboard LED state")
+                            .arg(
+                                Arg::with_name("u8")
+                                    .value_name("NAME")
+                                    .short("8")
+                                    .long("u8")
+                                    .help("output raw state as integer")
+                                    .takes_value(false),
+                            ),
+                    ),
+            )
             .arg(
                 Arg::with_name("verbose")
                     .short("v")
@@ -262,6 +287,20 @@ impl<'a> Job
                         )),
                 }
             },
+            ("leds", Some(subm)) =>
+                match subm.subcommand() {
+                    ("get", Some(subm)) => {
+                        let raw = subm.is_present("u8");
+                        Ok(Self::Leds(LedJob::Get(raw)))
+                    },
+                    (junk, _) =>
+                        Err(anyhow!(
+                            "invalid sub-subcommand to leds: [{}]; try ``{} \
+                             leds --help``",
+                            junk,
+                            clap::crate_name!()
+                        )),
+                },
             (junk, _) =>
                 Err(anyhow!(
                     "invalid subcommand [{}]; try ``{} --help``",
@@ -328,6 +367,8 @@ impl<'a> Job
             Self::Toggle(one, two) => Self::toggle_scheme(one, two)?,
             Self::Fade(from, to, ms, hz, clear) =>
                 Self::fade(from, to, ms, hz, clear)?,
+            Self::Leds(LedJob::Get(raw)) => Self::get_leds(raw)?,
+            Self::Leds(LedJob::Set) => unimplemented!(),
         }
 
         Ok(())
@@ -403,6 +444,23 @@ impl<'a> Job
         fade.commence(&fd)?;
         Ok(())
     }
+
+    /** Get the keyboard led state. */
+    fn get_leds(raw: bool) -> Result<()>
+    {
+        let fd = Console::current()?;
+        vrb!("console fd: {}", fd);
+
+        let leds = KbLedState::get(&fd)?;
+
+        if raw {
+            println!("{}", u8::from(leds));
+        } else {
+            println!("{}", leds);
+        }
+
+        Ok(())
+    }
 } /* [impl Job] */
 
 fn main() -> Result<()>