Feof method in PHP

Bool Feof ( Resource $ Handle ): Tests for end-of-file on a file pointer   The original words above the PHP manual. I used this for convenience.

   1   <?  PHP
  2      // If file can not be read or doesn' t exist fopen function returns false  
  3      $ File     =  @  Fopen  (  "  No_such_file  "  ,     "  R "  );
  4   
  5     //  False from fopen will issue warning and result in infinite loop here  
  6     While  (  !  Feof  (  $ File )){
  7   }
  8   
  9     Fclose  (  $ File  );
  10     ?>    

Indeed, this is relatively simple to use. However, if the above variable $ file is not a valid file pointer or has been disabled by fclose.

InProgramThe sixth line will generate a Waring, concurrent life cycle.

Why?

The reason is

ReturnsTrueIf the file pointer is at EOF or an error occurs (including socket timeout); Otherwise returnsFalse.

Therefore, for the sake of security, it is best to use the aboveCodeWhen you add a judgment, is_resource is relatively safe.