Vendor dependencies

Let's see how I like this workflow.

vendor/procfs/examples/netstat.rs

@@ -0,0 +1,53 @@
+#![allow(clippy::print_literal)]
+
+extern crate procfs;
+
+use procfs::process::{FDTarget, Stat};
+
+use std::collections::HashMap;
+
+fn main() {
+    // get all processes
+    let all_procs = procfs::process::all_processes().unwrap();
+
+    // build up a map between socket inodes and processes:
+    let mut map: HashMap<u64, Stat> = HashMap::new();
+    for p in all_procs {
+        let process = p.unwrap();
+        if let (Ok(stat), Ok(fds)) = (process.stat(), process.fd()) {
+            for fd in fds {
+                if let FDTarget::Socket(inode) = fd.unwrap().target {
+                    map.insert(inode, stat.clone());
+                }
+            }
+        }
+    }
+
+    // get the tcp table
+    let tcp = procfs::net::tcp().unwrap();
+    let tcp6 = procfs::net::tcp6().unwrap();
+
+    println!(
+        "{:<26} {:<26} {:<15} {:<8} {}",
+        "Local address", "Remote address", "State", "Inode", "PID/Program name"
+    );
+
+    for entry in tcp.into_iter().chain(tcp6) {
+        // find the process (if any) that has an open FD to this entry's inode
+        let local_address = format!("{}", entry.local_address);
+        let remote_addr = format!("{}", entry.remote_address);
+        let state = format!("{:?}", entry.state);
+        if let Some(stat) = map.get(&entry.inode) {
+            println!(
+                "{:<26} {:<26} {:<15} {:<12} {}/{}",
+                local_address, remote_addr, state, entry.inode, stat.pid, stat.comm
+            );
+        } else {
+            // We might not always be able to find the process assocated with this socket
+            println!(
+                "{:<26} {:<26} {:<15} {:<12} -",
+                local_address, remote_addr, state, entry.inode
+            );
+        }
+    }
+}