Add finger demo to redbean and fix regression

This change fixes a regression in unix.connect() caused by the recent addition of UNIX domain sockets. The BSD finger command has been added to third_party for fun and profit. A new demo has been added to redbean showing how a protocol as simple as finger can be implemented.
2025-06-27 06:48:31 +00:00 · 2022-06-23 03:39:44 -07:00 · 2022-06-23 03:39:44 -07:00 · 17cbe73411
commit 17cbe73411
parent 2415afab0e
34 changed files with 2454 additions and 29 deletions
--- a/tool/net/demo/unix-finger.lua
+++ b/tool/net/demo/unix-finger.lua
@ -0,0 +1,70 @@
+-- UNIX Finger Example
+
+local function WriteForm(host, user)
+   Write([[<!doctype html>
+     <title>redbean unix finger demo</title>
+     <style>
+       body { padding: 1em; }
+       h1 a { color: inherit; text-decoration: none; }
+       h1 img { border: none; vertical-align: middle; }
+       input { margin: .5em; padding: .25em; }
+       pre { margin-left: 2em; }
+       p { word-break: break-word; max-width: 650px; }
+       dt { font-weight: bold; }
+       dd { margin-top: 1em; margin-bottom: 1em; }
+       .hdr { text-indent: -1em; padding-left: 1em; }
+     </style>
+     <h1>
+       <a href="/"><img src="/redbean.png"></a>
+       <a href="unix-finger.lua">redbean unix finger demo</a>
+     </h1>
+     <p>
+       Your redbean is able to function as an finger client. Lua server
+       pages can use the <code>unix</code> module to implement protocols
+       that your redbean wasn't originally intended to support. All it
+       takes is few lines of code!
+     </p>
+     <form action="unix-finger.lua" method="post">
+       <input type="text" id="host" name="host" size="40"
+              value="%s" placeholder="host" autofocus>
+       <label for="host">host</label>
+       <br>
+       <input type="text" id="user" name="user" size="40"
+              value="%s" placeholder="user">
+       <label for="user">user</label>
+       <br>
+       <input type="submit" value="finger">
+     </form>
+   ]] % {EscapeHtml(host), EscapeHtml(user)})
+end
+
+local function main()
+   if IsPublicIp(GetClientAddr()) then
+      ServeError(403)
+   elseif GetMethod() == 'GET' or GetMethod() == 'HEAD' then
+      WriteForm('graph.no', 'new_york')
+   elseif GetMethod() == 'POST' then
+      ip = assert(ResolveIp(GetParam('host')))
+      fd = assert(unix.socket())
+      assert(unix.connect(fd, ip, 79))
+      assert(unix.write(fd, GetParam('user') .. '\r\n'))
+      response = ''
+      while true do
+         data = assert(unix.read(fd))
+         if data == '' then
+            break
+         end
+         response = response .. data
+      end
+      assert(unix.close(fd))
+      WriteForm(GetParam('host'), GetParam('user'))
+      Write('<pre>\r\n')
+      Write(EscapeHtml(VisualizeControlCodes(response)))
+      Write('</pre>\r\n')
+   else
+      ServeError(405)
+      SetHeader('Allow', 'GET, HEAD, POST')
+   end
+end
+
+main()