Add code for finding ELF magic number

src/main.rs

@@ -3,24 +3,34 @@ use std::env;
 use std::fs;
 use std::process::exit;
 
+const ELF_MAGIC_NUMBER: &[u8] = &[0x7F,0x45,0x4C,0x46];
+
 fn main() {
+    // Collect our execution args
     let args: Vec<String> = env::args().collect();
 
+    // Grab our filepath from our options
     let file_path = &args[1];
-    println!("Got target file '{}'", file_path);
-
     
     if path::Path::new(file_path).exists() {
         println!("File exists, reading '{}'", file_path);
+        
         let contents: Result<Vec<u8>, std::io::Error> = fs::read(file_path);
+        
         if contents.is_ok() {
             let bytes: &Vec<u8> = &contents.expect("");
-            for byte in bytes {
-                println!("{}", byte);
+            let magic_num: &[u8] = &bytes[0..4];
+        
+            if magic_num == ELF_MAGIC_NUMBER {
+                println!("Found ELF Magic Number!");
+            } else {
+                println!("[Error] Could not find magic number, is this an executable?")
             }
         }
     } else {
         println!("[Error] '{}' does not exist", file_path);
         exit(-1);
     }
+
+    return;
 }