ls: add more informative listing with -l (WIP)

Makefile

@@ -0,0 +1,5 @@
+PREFIX ?= ~/.local/bin/grutils
+file_list != find . -name '*.rs'
+
+all:
+	rust

src/ls.rs

@@ -1,11 +1,20 @@
 use std::env;
 use std::fs;
+use std::io::{stdout, Write};
+use std::path::Path;
+use std::os::unix::fs::PermissionsExt;
+
+/*extern crate chrono;
+use chrono::prelude::*;*/
 
 fn main(){
     let args: Vec<String> = env::args().collect();
-    let pwd = env::current_dir().unwrap();
+    // Flags vars
     let mut show_hidden = false;
     let mut show_prev_and_current = false;
+    let mut long_listing = false;
+    // Directories
+    let pwd = env::current_dir().unwrap();
     let mut dir = pwd.to_str();
     for arg in 1..args.len() {
         match args[arg].as_str() {
@@ -19,15 +28,18 @@ fn main(){
             "-A" | "--almost-all" => {
                 show_hidden = true;
                 show_prev_and_current = false;
-            }
+            },
+            "-l" => {
+                long_listing = true;
+            },
             arg => {
                 dir = Some(arg);
             },
         }
     }
-    list_dir(dir.unwrap().to_string(), show_hidden, show_prev_and_current);
+    list_dir(dir.unwrap().to_string(), show_hidden, show_prev_and_current, long_listing);
 }         
-fn list_dir(arg: String, show_hidden: bool, show_prev_and_current: bool) {
+fn list_dir(arg: String, show_hidden: bool, show_prev_and_current: bool, long_listing: bool) {
     let files = fs::read_dir(arg.clone()).unwrap();
     if show_hidden && show_prev_and_current {
         println!(".");
@@ -39,6 +51,30 @@ fn list_dir(arg: String, show_hidden: bool, show_prev_and_current: bool) {
         if file.clone().unwrap().display().to_string().starts_with('.') && !show_hidden {
             continue;
         }
-        println!("{}", file.unwrap().display());
+        if long_listing {
+            long_listing_format(Path::new(&path), file.unwrap().display().to_string());
+        } else {
+            print!("{} ", file.unwrap().display());
+        }
     }
+    if !long_listing {
+        print!("\n");
+    }
+    stdout().flush().unwrap();
+}
+
+fn long_listing_format(path: &Path, file: String) -> std::io::Result<()> {
+    let metadata = fs::metadata(path)?;
+    let modified = metadata.modified();
+    /*let timestamp = modified.parse::<i64>().unwrap();
+    let naive = NaiveDateTime::fromtimestamp(timestamp, 0);
+    let datetime: DateTime<Utc> = DateTime::from_utc(naive, Utc);*/
+    let mut permissions_string = String::new();
+    if metadata.is_dir() {
+        permissions_string.push('d');
+    } else {
+        permissions_string.push('-');
+    }
+    println!("{}{:o} {} {}", permissions_string, metadata.permissions().mode(), metadata.len(), file);
+    Ok(())
 }