Why is it whenever I use scandir() I receive periods at the beginning of the array?

Question 1

Array
(
    [0] => .
    [1] => ..
    [2] => bar.php
    [3] => foo.txt
    [4] => somedir
)
Array
(
    [0] => somedir
    [1] => foo.txt
    [2] => bar.php
    [3] => ..
    [4] => .
)

Question 2

Those are the current (.) and parent (..) directories. They are present in all directories, and are used to refer to the directory itself and its direct parent.

Question 3

Try using absolute file paths if your PHP scripts can be invoked (or requested) from different directories. For example, the current directory of a PHP script executed under example.com/one.php will be different from example.com/folder/two.php.

Your change to

$config['etc'] = parse_ini_file('../config/config.txt');

is still relative, except this time it's just "one directory up from the current directory > config > config.txt", rather than before, where you were looking in the same current directory.

A generic fix would be to do the following:

$root = $_SERVER['DOCUMENT_ROOT'];
// ... code ...
$config['etc'] = parse_ini_file($root . '/config/config.txt');

There are possible issues with using the DOCUMENT_ROOT field, but it should be fine for the most part (such as DOCUMENT_ROOT not being defined under the CLI). Also, check if DOCUMENT_ROOT has a trailing slash, even though the standard is not to have it, some hosts may have the trailing slash included. If it does, remove your slash at the beginning of your file path.

Question 4

Use unshift. It's like push, except it adds elements to the beginning of the array instead of the end.

unshift/push - add an element to the beginning/end of an array
shift/pop - remove and return the first/last element of an array

A simple diagram...

   unshift -> array <- push
   shift   <- array -> pop

and chart:

          add  remove  start  end
   push    X                   X
    pop           X            X
unshift    X             X
  shift           X      X

Check out the MDN Array documentation. Virtually every language that has the ability to push/pop elements from an array will also have the ability to unshift/shift (sometimes called push_front/pop_front) elements, you should never have to implement these yourself.

As pointed out in the comments, if you want to avoid mutating your original array, you can use concat, which concatenates two or more arrays together. You can use this to functionally push a single element onto the front or back of an existing array; to do so, you need to turn the new element into a single element array:

const array = [3, 2, 1]

const newFirstElement = 4

const newArray = [newFirstElement].concat(array) // [ 4, 3, 2, 1 ]

console.log(newArray);

concat can also append items. The arguments to concat can be of any type; they are implicitly wrapped in a single-element array, if they are not already an array:

const array = [3, 2, 1]

const newLastElement = 0

// Both of these lines are equivalent:
const newArray1 = array.concat(newLastElement) // [ 3, 2, 1, 0 ]
const newArray2 = array.concat([newLastElement]) // [ 3, 2, 1, 0 ]

console.log(newArray1);
console.log(newArray2);

Question 5

Assuming you are trying to access the remote server using HTTP, you won't be able to do this directly. Since HTTP is really going access the web service of your remote server, it controls how the files are presented to you. In the case of many web servers, you can turn on "indexes" for folder contents. This causes the entries in the folder to be displayed in your browser as HTML. In order to traverse the directory structure, you would need to parse this HTML to find the path information.

If you are using FTP, you can pass the ftp://... URL to opendir() as of version 5.0. Note that this capability can be turned off by your server admin. If you cannot use this feature directly, see the FTP functions manual for PHP (including ftp_nlist() for listing files).

An example from the above references:

<?php

// set up basic connection
$conn_id = ftp_connect($ftp_server);

// login with username and password
$login_result = ftp_login($conn_id, $ftp_user_name, $ftp_user_pass);

// get contents of the current directory
$contents = ftp_nlist($conn_id, ".");

// output $contents
var_dump($contents);

?>

Question 6

The example in the manual states:

It is usually best not to mix garbage-collected allocation with the system malloc-free. If you do, you need to be careful not to store pointers to the garbage-collected heap in memory allocated with the system malloc.

And more specifically for C++:

In the case of C++, you need to be especially careful not to store pointers to the garbage-collected heap in areas that are not traced by the collector. The collector includes some alternate interfaces to make that easier.

Looking at the source code in the manual you will see the garbage-collected memory is handled through specific calls, hence, the management is handled separately (either by the collector or manually). So as long your library handles its internals properly and doesn't expose collected memory, you should be fine. You don't know how other libraries manage their memory and you can use them as well, don't you? :)

Why is it whenever I use scandir() I receive periods at the beginning of the array?

Answers

php,directory