prototype

esgd.py

@@ -0,0 +1,66 @@
+import socketserver
+import os
+
+class GopherError(BaseException): pass
+class RequestError(GopherError): pass
+
+def recieveRequest(context):
+    data = b''
+    while data[-2:] != b'\r\n':
+        data += context.request.recv(1)
+    decoded = data[:-2].decode('utf-8')
+    return decoded
+
+def requestParser(request):
+    try:
+        if request[0] == '/': request = request[1:]
+    except IndexError: pass
+    request = request.replace('?', '\t').split('\t')
+    try: return (request[0], request[1])
+    except IndexError: return (request[0], "")
+
+def returnRelative(file):
+    gph = False
+    if file == "":
+        ret = "gophermap"
+        gph = True
+    elif os.path.isdir(file):
+        ret = file + "/gophermap"
+        gph = True
+    elif os.path.isfile(file): ret = file
+    else: raise RequestError('unreachable state')
+    return (ret, gph)
+
+def fileSendable(file): return os.access(file, os.F_OK|os.R_OK)
+
+def fileCGI(file):
+    return os.access(file, os.F_OK|os.R_OK|os.X_OK)
+
+def notFound(context):
+    context.request.sendall(b"3error: file not found!\r\n.\r\n")
+
+def sendFile(file, context):
+    with open(file, "r") as fd:
+        [context.request.sendall(
+            (i.rstrip() + "\r\n").encode("utf-8")
+        ) for i in fd.readlines()]
+        context.request.sendall(b".\r\n")
+
+class gopherHandler(socketserver.BaseRequestHandler):
+    def handle(self):
+        decoded = recieveRequest(self)
+        parsed = requestParser(decoded)
+
+        try: file = returnRelative(parsed[0])
+        except RequestError:
+            notFound(self)
+            return
+
+        if fileSendable(file[0]): sendFile(file[0], self)
+        else: notFound(self)
+
+if __name__ == "__main__":
+    HOST, PORT = "localhost", 85
+
+    with socketserver.TCPServer((HOST, PORT), gopherHandler) as server:
+        server.serve_forever()