This project objective consists on recreating some functionalities of [`wget`](https://www.gnu.org/software/wget/manual/wget.html) using a compiled language of your choice (like C, Rust, Go or other).
Wget is a free utility for non-interactive download of files from the Web. It supports HTTP, HTTPS, and FTP protocols, as well as retrieval through HTTP proxies.
To see more about wget you can visit the manual by using the command `man wget`, or you can visit the website [here](https://www.gnu.org/software/wget/manual/wget.html).
- Time that the program started: it must have the following format **yyyy-mm-dd hh:mm:ss**
- Status of the request. For the program to proceed to the download, it must present a response to the request as status OK (`200 OK`) if not, it should say which status it got and finish the operation with an error warning
- Size of the content downloaded: the content length can be presented as raw (bytes) and rounded to Mb or Gb depending on the size of the file downloaded
1. The flag `-B` should be handled, this flag should download a file immediately to the background and the output should be redirected to a log file. When the program containing this flag is executed it should output : `Output will be written to "wget-log"`. Example:
```console
$ go run . -B https://pbs.twimg.com/media/EMtmPFLWkAA8CIS.jpg
Output will be written to "wget-log".
$ cat wget-log
start at 2017-10-14 03:46:06
sending request, awaiting response... status 200 OK
3. It should also handle the path to where your file is going to be saved using the flag `-P` followed by the path to where you want to save the file, example:
4. The program should handle speed limit. Basically the program can control the speed of the download by using the flag `--rate-limit`. If you download a huge file you can limit the speed of your download, preventing the program from using the full possible bandwidth of your connection, example:
5. Downloading different files should be possible. For this the program will receive the `-i` flag followed by a file name that will contain all links that are to be downloaded. Example:
6. [**Mirror a website**](https://en.wikipedia.org/wiki/Mirror_site). This option should download the entire website being possible to use "part" of the website offline and for other useful [reasons](https://www.quora.com/How-exactly-does-Mirror-Site-works-and-how-it-is-done). For this you will have to download the website file system and save it into a folder that will have the domain name. Example: `http://www.example.com`, will be stored in a folder with the name `www.example.com` containing every file from the mirrored website. The flag should be `--mirror`.
The default usage of the flag will be to retrieve and parse the HTML or CSS from the given URL. This way retrieving the files that the document refers through tags. The tags that will be used for this retrieval must be `a`, `link` and `img` that contains attributes `href` and `src`.
You will have to implement some optional flags to go along with the `--mirror` flag.
Those flags will work based on [Follow links](https://www.gnu.org/software/wget/manual/wget.html#Following-Links). The command `wget` has several mechanisms that allows you to fine-tune which links it will follow. For This project you will have to implement the behavior of (note that this flags will be used in conjunction with the `--mirror` flag):
- [Types of Files](https://www.gnu.org/software/wget/manual/wget.html#Types-of-Files) (`--reject` short hand `-R`)
> this flag will have a list of file suffixes that the program will avoid downloading during the retrieval
- [Directory-Based Limits](https://www.gnu.org/software/wget/manual/wget.html#Directory_002dBased-Limits) (`--exclude` short hand -X)
> this flag will have a list of paths that the program will avoid to follow and retrieve. So if the URL is `https://example.com` and the directories are `/js`, `/css` and `/assets` you can avoid any path by using `-X=/js,/assets`. The fs will now just have `/css`.
