[release] cpufreq v1.0.0

A simple tool to show the current average CPU frequency across all
CPU cores. Can be given the argument `-a` to show frequency for each
individual core.

src/main.rs

@@ -0,0 +1,49 @@
+use std::{env::args, fs};
+
+static LINUX_SYSFS_CPUFREQ_BASE_DIR: &str = "/sys/devices/system/cpu/cpufreq";
+
+fn show_all() {
+    let mut cpu_num = 0;
+
+    loop {
+        let path = format!("{LINUX_SYSFS_CPUFREQ_BASE_DIR}/policy{cpu_num}/scaling_cur_freq");
+
+        if let Ok(scaling_cur_freq) = fs::read_to_string(path) {
+            println!("{}", scaling_cur_freq.trim().parse::<u64>().unwrap() / 1000);
+        } else {
+            break;
+        }
+
+        cpu_num += 1;
+    }
+}
+
+fn show_average() {
+    let mut sum = 0;
+    let mut count = 0;
+
+    for dir in fs::read_dir(LINUX_SYSFS_CPUFREQ_BASE_DIR).unwrap() {
+        let mut path = dir.unwrap().path();
+        path.push("scaling_cur_freq");
+
+        if let Ok(scaling_cur_freq) = fs::read_to_string(path) {
+            let freq: u64 = scaling_cur_freq.trim().parse().unwrap();
+            sum += freq;
+            count += 1;
+        }
+    }
+
+    println!("{}", sum / count / 1000);
+}
+
+fn main() {
+    let all = args()
+        .nth(1)
+        .filter(|opt| opt == "-a" || opt == "--all")
+        .is_some();
+
+    match all {
+        true => show_all(),
+        false => show_average(),
+    }
+}