slowcat v1.0

src/main.rs

@@ -0,0 +1,43 @@
+use std::{
+    env,
+    io::{stdin, stdout, Read, StdoutLock, Write},
+    time::Duration,
+};
+
+static DEFAULT_HZ: u32 = 100;
+
+fn output_slow(data: &[u8], hz: u32, out: &mut StdoutLock) {
+    // write 1 byte at a time
+    for i in 0..data.len() {
+        out.write_all(&data[i..i + 1]).unwrap();
+        out.flush().unwrap();
+
+        // sleep according to given frequency
+        std::thread::sleep(Duration::from_secs_f64(1.0 / hz as f64));
+    }
+}
+
+fn main() {
+    let hz: u32 = env::args()
+        .nth(1)
+        .map_or(DEFAULT_HZ, |s| s.parse().unwrap());
+
+    let mut out = stdout().lock();
+    let mut buf = [0u8; 8 * 1024];
+
+    // read 8k
+    while let Ok(n) = stdin().read(&mut buf) {
+        if n == 0 {
+            break; // EOF
+        }
+
+        let data = &buf[..n];
+        if hz != 0 {
+            // slow output with delay according to given frequency
+            output_slow(data, hz, &mut out);
+        } else {
+            // normal output without delay if given frequency is zero
+            out.write_all(data).unwrap();
+        }
+    }
+}