implement print pidfile as table

Cargo.toml

@@ -21,3 +21,4 @@ dirs = "1.0"
 log = "0.4"
 env_logger = "0.6.0"
 rand = "0.6"
+prettytable-rs = "^0.8"

src/main.rs

@@ -1,7 +1,8 @@
 #[macro_use]
 extern crate serde_derive;
 extern crate env_logger;
-
+#[macro_use]
+extern crate prettytable;
 use std::process::exit;
 
 use clap::{crate_name, crate_version, App, Arg, SubCommand};
@@ -13,6 +14,7 @@ mod container;
 mod image;
 mod mounts;
 mod network;
+mod pids;
 mod runner;
 
 fn main() {
@@ -72,11 +74,17 @@ fn main() {
                         .takes_value(true),
                 ),
         )
+        .subcommand(
+            SubCommand::with_name("ps")
+                .version(crate_version!())
+                .about("show containers"),
+        )
         .get_matches();
 
     match &app_matches.subcommand() {
         ("run", Some(sub_m)) => runner::run(&sub_m),
         ("pull", Some(sub_m)) => runner::pull(&sub_m),
+        ("ps", Some(sub_m)) => pids::show(&sub_m),
         _ => {
             eprintln!("Unexpected arguments");
             app.print_help().unwrap();

src/pids.rs

@@ -0,0 +1,33 @@
+use std::path::Path;
+
+use clap::ArgMatches;
+use prettytable::{Cell, Row, Table};
+
+use nix::unistd::Pid;
+
+pub fn show(sub_m: &ArgMatches) {
+    // Create the table
+    let mut table = Table::new();
+
+    table.add_row(row!["Container ID", "PID"]);
+    for i in 0..3 {
+        let pidfile = Pidfile::read(Path::new("/hoge"));
+        table.add_row(row![pidfile.name, pidfile.pid]);
+    }
+
+    table.printstd();
+}
+
+struct Pidfile {
+    pid: Pid,
+    name: String,
+}
+
+impl Pidfile {
+    fn read(path: &Path) -> Self {
+        Pidfile {
+            pid: Pid::from_raw(1000),
+            name: "library/alpine:latest".to_string(),
+        }
+    }
+}