Vendor dependencies

Let's see how I like this workflow.

vendor/procfs/examples/self_memory.rs

@@ -0,0 +1,56 @@
+use procfs::process::Process;
+
+fn main() {
+    let me = Process::myself().expect("Unable to load myself!");
+    println!("PID: {}", me.pid);
+
+    let page_size = procfs::page_size().expect("Unable to determinte page size!") as u64;
+    println!("Memory page size: {}", page_size);
+
+    // Note: when comparing the below values to what "top" will display, note that "top" will use
+    // base-2 units (kibibytes), not base-10 units (kilobytes).
+
+    if let Ok(stat) = me.stat() {
+        println!("== Data from /proc/self/stat:");
+        println!("Total virtual memory used: {} bytes", stat.vsize);
+        println!(
+            "Total resident set: {} pages ({} bytes)",
+            stat.rss,
+            stat.rss as u64 * page_size
+        );
+        println!();
+    }
+
+    if let Ok(statm) = me.statm() {
+        println!("== Data from /proc/self/statm:");
+        println!(
+            "Total virtual memory used: {} pages ({} bytes)",
+            statm.size,
+            statm.size * page_size
+        );
+        println!(
+            "Total resident set: {} pages ({} byte)s",
+            statm.resident,
+            statm.resident * page_size
+        );
+        println!(
+            "Total shared memory: {} pages ({} bytes)",
+            statm.shared,
+            statm.shared * page_size
+        );
+        println!();
+    }
+
+    if let Ok(status) = me.status() {
+        println!("== Data from /proc/self/status:");
+        println!(
+            "Total virtual memory used: {} bytes",
+            status.vmsize.expect("vmsize") * 1024
+        );
+        println!("Total resident set: {} bytes", status.vmrss.expect("vmrss") * 1024);
+        println!(
+            "Total shared memory: {} bytes",
+            status.rssfile.expect("rssfile") * 1024 + status.rssshmem.expect("rssshmem") * 1024
+        );
+    }
+}