PHP正则表达式查找以_开头的图像

Question

I have a function that loads all image files it finds in the wordpress uploads directory. I'd like to modify it slightly so that it skips over any image that begins with an underscore character, "_someimage.jpg" is skipped, while "someimage.jpg is not...

Here is the existing function....

 $dir = 'wp-content/uploads/';
 $url = get_bloginfo('url').'/wp-content/uploads/';
 $imgs = array();
  if ($dh = opendir($dir)) 
  {
  while (($file = readdir($dh)) !== false) 
   {
   if (!is_dir($file) && preg_match("/\.(bmp|jpeg|gif|png|jpg|)$/i", $file)) 
   {
   array_push($imgs, $file);
   }
  }
  closedir($dh);
  } else {
   die('cannot open ' . $dir);
  }

Answer 1

You can modify your current regex or add an boolean expression using strstr (which I'd recommend).

Modifying your current regex:

"/^[^_].*\.(bmp|jpeg|gif|png|jpg)$/i"

Or a simple expression to detect underscores in the string would be:

strstr($file, '_')

edit: and actually you could use substr :

substr($file, 0, 1) != '_'

Answer 2

if (!is_dir($file) && preg_match("/\.(bmp|jpeg|gif|png|jpg|)$/i", $file)) 

可以转化为：

if (!is_dir($file) && preg_match("/^[^_].*\.(bmp|jpeg|gif|png|jpg|)$/i", $file))