Having spent hours tacking down a copy() error: Permission denied , (and duly worrying about chmod on winXP) , its worth pointing out that the 'destination' needs to contain the actual file name ! --- NOT just the path to the folder you wish to copy into.......
DOH !
hope this saves somebody hours of fruitless debugging

It take me a long time to find out what the problem is when i've got an error on copy(). It DOESN'T create any directories. It only copies to existing path. So create directories before. Hope i'll help,

Don't forget; you can use copy on remote files, rather than doing messy fopen stuff.  e.g.

<?php
if(!@copy('http://someserver.com/somefile.zip','./somefile.zip'))
{
    $errors= error_get_last();
    echo "COPY ERROR: ".$errors['type'];
    echo "<br />\n".$errors['message'];
} else {
    echo "File copied from remote!";
}
?>

Here is a simple script that I use for removing and copying non-empty directories. Very useful when you are not sure what is the type of a file.

I am using these for managing folders and zip archives for my website plugins.

<?php

// removes files and non-empty directories
function rrmdir($dir) {
  if (is_dir($dir)) {
    $files = scandir($dir);
    foreach ($files as $file)
    if ($file != "." && $file != "..") rrmdir("$dir/$file");
    rmdir($dir);
  }
  else if (file_exists($dir)) unlink($dir);
} 

// copies files and non-empty directories
function rcopy($src, $dst) {
  if (file_exists($dst)) rrmdir($dst);
  if (is_dir($src)) {
    mkdir($dst);
    $files = scandir($src);
    foreach ($files as $file)
    if ($file != "." && $file != "..") rcopy("$src/$file", "$dst/$file"); 
  }
  else if (file_exists($src)) copy($src, $dst);
}
?>

Cheers!

A nice simple trick if you need to make sure the folder exists first:

<?php

$srcfile='C:\File\Whatever\Path\Joe.txt';
$dstfile='G:\Shared\Reports\Joe.txt';
mkdir(dirname($dstfile), 0777, true);
copy($srcfile, $dstfile);

?>

That simple.

On Windows, php-7.4.19-Win32-vc15-x64 - copy() corrupted a 6GB zip file. Our only recourse was to write:

function file_win_copy( $src, $dst ) {
 shell_exec( 'COPY "'.$src.'" "'.$dst.'"');
 return file_exists($dest);
}

Here's a simple recursive function to copy entire directories

Note to do your own check to make sure the directory exists that you first call it on.

<?php
function recurse_copy($src,$dst) {
    $dir = opendir($src);
    @mkdir($dst);
    while(false !== ( $file = readdir($dir)) ) {
        if (( $file != '.' ) && ( $file != '..' )) {
            if ( is_dir($src . '/' . $file) ) {
                recurse_copy($src . '/' . $file,$dst . '/' . $file);
            }
            else { 
                copy($src . '/' . $file,$dst . '/' . $file);
            }
        }
    }
    closedir($dir);
}
?>

It's worth noting that copy() sets the destination file's last modified time/date.

If you try to copy a file to itself - e.g. if the target directory is just a symlink to the source directory - copy will return false. just like on the command line.

some hosts disable copy() function and say its for security 

and for some copy is important so this is and simple function that do same as copy function effect 

how smart php can help us l like php 

<?php
    function copyemz($file1,$file2){
          $contentx =@file_get_contents($file1);
                   $openedfile = fopen($file2, "w");
                   fwrite($openedfile, $contentx);
                   fclose($openedfile);
                    if ($contentx === FALSE) {
                    $status=false;
                    }else $status=true;
                    
                    return $status;
    }
?>

Copying large files under Windows 8.1, from one NTFS filesystem to another NTFS filesystem, results in only the first 4 GiB copied and the rest of the file is ignored.

So, if you think to have files larger than 4 GiB, instead of doing:
   copy($source,$destination);
it is much better to do something like:
   exec("xcopy $source $destination");

I will check to see if this issue is valid also under Linux.
It depends on PHP not being compiled in 64 bit mode?