title: How to read a file into a C program on Linux?
body: <p>What is the difference between running an already compiled C program with <code>a.out file_name_here</code> and <code>a.out &lt; file_name_here</code>?</p>
  
  <p>I remember something about Linux pipelines, but I cannot remember how to make the <code>a.out</code> file accept a file using the <code>&lt;</code> symbol.</p>
  
  <p>Basically what I am asking is this: how does the C code look for a C program that:</p>
  
  <ol>
  <li>file_name_here is a text file with "hello world" as content</li>
  <li>terminal gets "a.out &lt; file_name_here" in command line</li>
  <li>terminal shows output: "hello world"</li>
  </ol>