Best Way to Determine If a File Is Empty (Php)

Best way to determine if a file is empty (php)?

file_get_contents() will read the whole file while filesize() uses stat() to determine the file size. Use filesize(), it should consume less disk I/O and much less memory.

Check if specific input file is empty

You can check by using the size field on the $_FILES array like so:

if ($_FILES['cover_image']['size'] == 0 && $_FILES['cover_image']['error'] == 0)
{
    // cover_image is empty (and not an error)
}

(I also check error here because it may be 0 if something went wrong. I wouldn't use name for this check since that can be overridden)

IF file is !empty ELSE

<?
$file = 'config/config2.php';

if(filesize($file)!=0)// NB:an empty 'looking' file could have a file size above 0
{
some code here!
}
else
{
some other code here!
}
?>

how to know if a file is empty or not

The $_FILES always have

 [file] => Array
    (
        [name] => MyFile.jpg
        [type] => image/jpeg
        [tmp_name] => /tmp/php/php6hst32
        [error] => UPLOAD_ERR_OK
        [size] => 98174
    )

You can use the following to get the size

$_FILES['file']['size']

Check if file-input[] is empty

if ($_FILES['file_input']){
  foreach($_FILES['file_input']['name'] as $k=>$v){
    if(!empty($_FILES['file_input']['name'][$k])){
       if($_FILES['file_input']['size'][$k]>0){
         // all ok, can be moved ..
       }
    }
  }
}

How can I use PHP to check if a directory is empty?

It seems that you need scandir instead of glob, as glob can't see unix hidden files.

<?php
$pid = basename($_GET["prodref"]); //let's sanitize it a bit
$dir = "/assets/$pid/v";

if (is_dir_empty($dir)) {
  echo "the folder is empty"; 
}else{
  echo "the folder is NOT empty";
}

function is_dir_empty($dir) {
  if (!is_readable($dir)) return null; 
  return (count(scandir($dir)) == 2);
}
?>

Note that this code is not the summit of efficiency, as it's unnecessary to read all the files only to tell if directory is empty. So, the better version would be

function dir_is_empty($dir) {
  $handle = opendir($dir);
  while (false !== ($entry = readdir($handle))) {
    if ($entry != "." && $entry != "..") {
      closedir($handle);
      return false;
    }
  }
  closedir($handle);
  return true;
}

By the way, do not use words to substitute boolean values. The very purpose of the latter is to tell you if something empty or not. An

a === b

expression already returns Empty or Non Empty in terms of programming language, false or true respectively - so, you can use the very result in control structures like IF() without any intermediate values

check if $_FILES is empty or not, file size, file exists

You can get filesize in bytes by:

$_FILES['img']['size']

for checking if it's image file or not or image file format you can check $_FILES['img']['tmp_name'] by getimagesize() like this: php how to use getimagesize() to check image type on upload

for checking if file uploaded or not you can check it with error. error number 4 means file not uploaded:

if ($_FILES['img']['error']==4){
    echo 'Not uploaded';
}

here you can see more information about Error Messages Number

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