PHP ftell(): Find Current Position of File Pointer

The PHP ftell() function is used when we need to find the current position of the file pointer in the file. For example:

<?php
   $file = "codescracker.txt";
   $fp = fopen($file, "r");
   
   $character = fgetc($fp);
   echo $character;
   $currentPos = ftell($fp);
   echo "<br>The current position of file pointer: " . $currentPos;
   
   fclose($fp);
?>

The output produced by the above PHP example on the ftell() function is:

And here is the snapshot of the file codescracker.txt used in the above example:

Let me modify the above example to convert to a self-defined example of the ftell() function in PHP:

<?php
   $fp = fopen("codescracker.txt", "r");
   
   if($fp)
   {
      echo "<p>The current position: " .ftell($fp). "</p>";
      
      echo "<p>The first character: " .fgetc($fp). "</p>";
      echo "<p>Now the current position: " .ftell($fp). "</p><hr>";
      
      echo "<p>The next (second) character: " .fgetc($fp). "</p>";
      echo "<p>The current position: " .ftell($fp). "</p><hr>";
      
      echo "<p>The next (third) character: " .fgetc($fp). "</p>";
      echo "<p>The current position: " .ftell($fp). "</p>";
      
      fclose($fp);
   }
   else
      echo "<p>Unable to open the file</p>";
?>

Now the output should be:

PHP ftell() Syntax

The syntax of the ftell() function in PHP is:

ftell(filePointer)

Advantages of the ftell() function in PHP

• Position of the file pointer is accurate thanks to the "ftell()" function, which is available for any given file.
• Useful for both reading and writing files: This function is helpful for a variety of file handling tasks because it can be used for both reading and writing files.
• Can be used with other file functions: To carry out more complex file operations, the "ftell()" function can be combined with other file functions like "fseek()" and "rewind()."

Disadvantages of the ftell() function in PHP

• Not helpful for very large files: The "ftell()" function may not be helpful for very large files because it may return a value that is larger than the integer range.
• The "ftell()" function might not function properly with non-seekable streams, such as pipes or network sockets.
• Not thread-safe: The "ftell()" function is not thread-safe, which means that the outcome may be unpredictable if multiple threads access the same file.

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