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|It's suprisingly easy to use gopher and http without a proper client. |
| |
|To access gopher: |
| |
|The default port is 70, so use that if one is not specified. |
|To access gopher://host:port/0,1/path in your terminal, type this: |
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telnet host port
/path
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|Then, the document should show up on your terminal. You may also type path |
|without the slash, which will also work. |
| |
|to access gopher://host:port/7/path?query (a search query), type this: |
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telnet host port
/path<tab>query
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|<tab> is the tab key (You can also use a "?" instead in some cases.). |
| |
|To access HTTP: |
| |
|The default port is 80, so use that if one is not specified. |
|to access http://host:port/path?query in your terminal, type this: |
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telnet host port
GET /path?query
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|You have to press enter twice after typing the last line, but then you will |
|get the file you asked the web server for. |
| |
|You can also use the "long format" which lets you send headers. Headers are |
|little pieces of information about how the connection is carried out. For |
|example, you could send "Connection: keep-alive", which will tell the server |
|that you want to make another request without closing the connection (You |
|wouldn't need to reopen telnet to start with a new request to the same server)|
|(It's there just to make things go faster under the hood.) |
| |
|The one header that is required is "Host: host", where "host" is the same as |
|the host you put as the first argument to telnet. It might seem crazy that the|
|server doesn't know it's own name, but sometimes one server will serve |
|multiple websites at once, so it needs to know which one is which. |
| |
|Headers are case-insensitive, and spacing doesn't matter, though one space |
|is preferred. The standard says "any LWS," so you don't need space characters |
|specifically. |
| |
|A request might look something like this: |
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telnet host port
GET /path?query HTTP/1.0
Host: host
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|Make sure you press enter twice after typing your header (or headers if you |
|have multiple). |
| |
|You can also use HTTP/1.1, which gives you more stuff you can do, but is more |
|complicated. It also does "Connection: keep-alive" by default, and to remove |
|it, you do "Connection: close", which is the default in HTTP/1.0. The server |
|will occasionally decide it doesn't like your header, and do what it wants. |
|Not every server cares about your headers. It's a mean world out there. |
| |
|Let's do a HTTP/1.1 example: |
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telnet dread.life 80
GET / HTTP/1.1
Host: dread.life ============================================================
| <-- Press enter twice. The following is from the server. |
HTTP/1.1 200 OK ============================================================
Connection: keep-alive
Content-Length: 1104
Content-Type: text/html
Date: Sun, 15 Apr 2018 20:06:57 GMT
Last-Modified: Sun, 15 Apr 2018 19:48:13 GMT
Server: OpenBSD httpd ===========================================
| <-- Headers end here. File starts here. |
<!DOCTYPE=html> ===========================================
<html>
<head>
<meta charset="utf-8">
<title>Homepage of the Dabmancer</title>
<link rel="stylesheet" href="/style.css">
<body>
<ul class="navbar">
<li class="navbar"><a href="/">Home</a></li>
<li class="navbar">
<a href="http://gopher.floodgap.com/gopher/gw.lite?gopher://dread.life:70/1/">
Gopherhole</a></li>
<li class="navbar"><a href="/links.html">Links</a></li>
</ul>
<h3>Welcome to my website.</h3>
<p>The "Gopherhole" tab will take you to my gopherhole, which is like a website,
but is on the gopher protocol, rather than http. It will get you there through a
http-to-gopher proxy, so you can just use your regular web browser instead of a
special gopher client.</p>
<p>"Links" is a page that has links to websites I find useful or interesting. If
I keep going back to it, it will end up on that page.</p>
</body>
</html>
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|Make sure that you press enter twice after every HTTP request. |
| |
|The first thing a server gives you is an error code. It worked right, so it |
|gave us an "OK." |
| |
|As you can see, the server returns headers, too, before giving you your html |
|file. You know what a connection header is. Content-length is the length of |
|the file, in bytes. The alternative to content-length is "Transfer-Encoding: |
|Chunked", which is where the file is transmitted in increments, with the size |
|of the increment on its own line above the increment. It's useful for files |
|that are generated on-the-fly. "Content-Type:" is usually "text/html" or |
|"text/plain", but there are special content types for images and video. |
|"Date" and "Last-Modified" are pretty self-explanatory. "Server" is the |
|HTTP server you're using to transmit things. Usually, you'll see nginx or |
|Apache, but Google has it's own server. The server can transmit whatever kind |
|of wacky headers it wants, so don't be suprised if you see something that |
|is completely nonstandard. |
| |
|If you want to use ssl/tls (e.g. like you need to for https), replace "telnet |
|host port" with "openssl s_client -connect host:port" This will work with |
|http, but should work with gopher over ssl or tls as well. I just haven't seen|
|a server that uses gopher+tls, and I don't know what the port would be. |
| |
|The gopher part of this tutorial was pretty comprehensive, but I only covered |
|HTTP's GET requests, even though there are POST, DELETE, PUT, etc. |
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