title: What is substitute character and how to process it in windows
body: <p>I get a text file from aix and try to process it on windows</p>
  
  <p>but some lines contains strange character like <img src="https://i.stack.imgur.com/oSp83.png" alt="sub character">, in ultraedit , it is displayed like <img src="https://i.stack.imgur.com/JKTnf.png" alt="arrow"></p>
  
  <p>when fgets function encounter the line, it raise a ferror and stop at drawing. Then it refuse to continue even if I force to run fgets again on after meets the line.</p>
  
  <p>The hexa code of the character is 1A</p>
  
  <p>The explanation of this character in ASCII table is substitute character, which is used to replace the character that cannot be represented on the device.</p>
  
  <p>Does that means </p>
  
  <ol>
  <li>I have a specific character of AIX and there is no way to process it on windows.</li>
  <li>Does this happens only in case of a cross plateform file ?</li>
  </ol>
  
  <p>Thanks!</p>