Question: I have an ASCII-art box and I need a program to open it.

Examples
--------

Input:

```
-------
|     |
|_____|

```

Output:

```
      /
     /
    /
   /
  /
 /
/
|     |
|_____|

```

Specification
=============

* The first line will only consist of `-`, at least 3 of them
* The middle rows will start with `|` have spaces, and end with `|`
	+ All the middle rows will be the same
* The last row will start with `|` have `_` and end with a `|`
* All rows will be the same length

Opening the box:

* Each `-` should be replaced by a `/` in ascending lines and position.

Answer: 
Retina, ~~34~~ 20 bytes
=======================

```
-(?=(-*))¶?
$1/¶
-

```

In the first step every `-` is substituted with the `-`'s following it, a `/` and a newline. The newline at the end of the original first line is deleted. In the second step we change the new `-`'s to spaces which results in the desired output.

[Try it online here.](http://retina.tryitonline.net/#code=LSg_PSgtKikpwrY_CiQxL8K2Ci0KIA&input=LS0tLS0tLQp8ICAgICB8CnxfX19fX3w)
PowerShell, 55 bytes
--------------------

```
$d,$b=$args-split"`n";($d.length-1)..0|%{" "*$_+"/"};$b

```

Takes input `$args` as a string, `-split`s on newlines  ``n` ([reference link](https://technet.microsoft.com/en-us/library/hh847835.aspx)), stores the first line into `$d` (as a string) and the remaining into `$b` (as an array of strings). We then loop from the `length` of the first line (minus 1) to `0` and each iteration output that number of spaces plus a `/`. Finally, output `$b` (the rest of the input string) which by default will output one per line.

### Example Run

```
PS C:\Tools\Scripts\golfing> .\help-me-open-the-box.ps1 "----`n|  |`n|__|"
   /
  /
 /
/
|  |
|__|

```