initial commit (ugly but works): linkspeed <netdev name>

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "linkspeed"
+version = "0.1.0"

Cargo.toml

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+[package]
+name = "linkspeed"
+version = "0.1.0"
+edition = "2024"
+rust-version = "1.85"
+
+[dependencies]

rust-toolchain.toml

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+[toolchain]
+channel = "nightly"

src/main.rs

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+use std::{
+    env,
+    fs::File,
+    io::{self, Read, Seek, SeekFrom},
+    thread::sleep,
+    time::{Duration, Instant},
+};
+
+struct LinkSpeed {
+    rx: File,
+    tx: File,
+    rx_bytes: u64,
+    tx_bytes: u64,
+    time: Instant,
+}
+
+impl LinkSpeed {
+    pub fn new(dev: String) -> io::Result<Self> {
+        let rx_bytes_file = File::open(format!("/sys/class/net/{dev}/statistics/rx_bytes"))?;
+        let tx_bytes_file = File::open(format!("/sys/class/net/{dev}/statistics/tx_bytes"))?;
+
+        Ok(Self {
+            rx: rx_bytes_file,
+            tx: tx_bytes_file,
+            rx_bytes: 0,
+            tx_bytes: 0,
+            time: Instant::now(),
+        })
+    }
+
+    fn read_bytes(file: &mut File) -> io::Result<u64> {
+        file.seek(SeekFrom::Start(0))?;
+        let mut buf = String::new();
+        file.read_to_string(&mut buf)?;
+        Ok(buf.trim().parse().unwrap_or(0))
+    }
+
+    fn update(&mut self) -> io::Result<(u64, u64)> {
+        let rx_bytes = Self::read_bytes(&mut self.rx)?;
+        let tx_bytes = Self::read_bytes(&mut self.tx)?;
+
+        let mut rx_diff = rx_bytes - self.rx_bytes;
+        let mut tx_diff = tx_bytes - self.tx_bytes;
+
+        if self.rx_bytes == 0 {
+            self.rx_bytes = rx_bytes;
+            rx_diff = 0;
+        }
+
+        if self.tx_bytes == 0 {
+            self.tx_bytes = tx_bytes;
+            tx_diff = 0;
+        }
+
+        self.rx_bytes = rx_bytes;
+        self.tx_bytes = tx_bytes;
+
+        Ok((rx_diff, tx_diff))
+    }
+
+    pub fn get_measurement(&mut self) -> (f64, f64) {
+        let elapsed = self.time.elapsed().as_secs_f64();
+        let (rx, tx) = self.update().unwrap();
+        let rx_speed = rx as f64 / elapsed;
+        let tx_speed = tx as f64 / elapsed;
+        self.time = Instant::now();
+        (rx_speed, tx_speed)
+    }
+}
+
+fn main() {
+    let netdev_name = env::args().nth(1).expect("No network device provided");
+
+    let mut link_speed = LinkSpeed::new(netdev_name).expect("Failed to create LinkSpeed object");
+
+    loop {
+        let (rx_speed, tx_speed) = link_speed.get_measurement();
+        println!(
+            "RX: {:.0} MBit/s, TX: {:.0} MBit/s",
+            rx_speed / 1024.0 / 1024.0 * 8.0,
+            tx_speed / 1024.0 / 1024.0 * 8.0
+        );
+        sleep(Duration::from_millis(1000));
+    }
+}