Retrieve and print command behind pid

README.md

@@ -17,8 +17,8 @@ loadtimer -s 2 -b 0 -n 3 `pidof logd`
 Benchmarking PIDs [229]
 3 sample(s) of 60s
 
-| Description         | CPU usage % | total mean | utime mean | utime stddev | stime mean | stime stddev |
-| 229, 3 samples, 60s |         2.5 |        5.0 |        1.3 |         0.58 |        3.7 |         0.58 |
+| Description | CPU usage % | total mean | utime mean | utime stddev | stime mean | stime stddev |
+|        logd |         2.5 |        5.0 |        1.3 |         0.58 |        3.7 |         0.58 |
 ```
 
 If you want to build from source, e.g. for Android:

src/lib.rs

@@ -1,3 +1,5 @@
+use std::fs;
+
 use anyhow::Result;
 use nix::unistd::SysconfVar;
 
@@ -16,3 +18,9 @@ pub fn get_user_hz() -> Result<i64> {
         "failed to retreive USER_HZ / SC_CLK_TCK / jiffies"
     ))
 }
+
+/// Get the command behind a process.
+pub fn get_process_command(pid: usize) -> Result<String> {
+    let path = format!("/proc/{pid}/comm");
+    fs::read_to_string(path).map_err(Into::into)
+}

src/main.rs

@@ -1,6 +1,7 @@
 use anyhow::Result;
 use loadtimer::{
-    cli::Cli, dump::print_proc_metrics, eval::ProcMetrics, get_user_hz, sample::Sampler,
+    cli::Cli, dump::print_proc_metrics, eval::ProcMetrics, get_process_command, get_user_hz,
+    sample::Sampler,
 };
 use std::time::Duration;
 
@@ -27,7 +28,7 @@ fn main() -> Result<()> {
     let descriptions = args
         .pids
         .iter()
-        .map(|pid| format!("{pid}, {} samples, {}s", args.num_samples, args.sample_secs));
+        .map(|pid| get_process_command(*pid).unwrap_or_else(|_| format!("PID {pid}")));
 
     println!();
     print_proc_metrics(&metrics, descriptions);