i have a program that receives data from a wireless device over bluetooth...i now need to do some operations in the data and then send it to the website (web server!!!) as a .csv file...i also need to authenticate the device itself from it hardware address which is also obtained in the program.i am coding this in gcc linux compiler using C...can anyone tell me how do i go about doing this?
You should look into the LibCurl library. It handles uploading via HTTP and a number of other protocols.
Related
I have to write a C++ applicaton that has to read images from a local directory on client computer (linux, ubuntu) and send them to a server (linux, ubuntu).
There will be almost 1000 of such clients.
Assuming that the rest of my program is written in C++ I need some hint on what library+technologies to use to achieve this goal?
That would depend on a number of variables.
First, determine what type of format does the server accept? Is it SOAP or not? If yes, you can stream data to the server. Otherwise, you need to read the entire file first and then, send it.
Second, here is a very good article on how to create a web request in C++. Have a look at it: How do you make a HTTP request with C++?
I'm trying to use AT commands to setup a BGS2-W modem on a custom board to connect to a site over TLS, but the modem is not reacting to my commands and no certificates are being set.
I'm using the command
AT^SBNW
to send the commands as documented in Transport Layer Security for Client
TCP/IP Services doc (https://ptelectronics.ru/wp-content/uploads/organizatsiya_bezopasnogo_ssl-soedineniya.pdf#page=8).
Unfortunately, the document provides no examples, and I haven't been able to find any samples showing the usage of this command online.
The document linked has a java commandline tool attached that will send a cert from a PC, however I am unable to use this tool (I don't have the connection to the modem).
If anyone has any idea's on how to use this command I could very much use the help.
Note: I'm trying to set the certificates from within code running on a PIC18 - this isn't a final incarnation, I just need the certificates loaded so I can connect to our secure server.
Well, guess this one isn't going to find an answer anytime soon :)
So, its fairly easy to capture the output from the javatool - I'm using Com0Com to emulate 2 connected ports, then using termite to manually input on one port while telling the java app to connect to the other.
The first query from the java app expects an "OK" response, I find it easiest to send the response before starting the java app (I guess it gets cached in the recv buffer of the emulated port).
The javatool then sends "AT^SBNW=is_cert,1\r", and you can type in the reply in termite "SECURE CMD READY: SEND COMMAND ..."
After this a large binary dump comes through. You can decode the dump using the structure described in Application Note 62 (https://ptelectronics.ru/wp-content/uploads/organizatsiya_bezopasnogo_ssl-soedineniya.pdf). That should get all the data required to generate the same binary within code.
I'm searching for an efficient solution to make a C Freebsd platform communicate with a Node.js server.
Here are my requirements:
the client must be able to send binary streams and text messages (typically JSON messages)
those messages can be multiplexed: for instance, a text message can be sent while a binary stream is being sent.
I was heading to the libwebsockets library, but it seems to be a half-dead project, no multiplexing extension support, for instance.
I thought to implement a TCP/IP solution myself.
Do you know of any HTTP client library in C (with SSL support) that also allows direct communication with the remote server?
I have a client-server application where the client uses HTTP to start a session in the server and then tells the server to switch the connection from HTTP to a different protocol. All communication is encapsulated in SSL. It is written in Perl and works well, but I'm looking into implementing the client in C.
I know libcurl gives you access to the underlaying socket but it's not enough because of the SSL requirement.
Notice that libcurl doesn't do the SSL part by itself, it uses OpenSSL. So, if you can get the socket handle from libcurl after the first HTTP interactions, AND the session key it uses (some spelunking required) you can go on directly with OpenSSL from that point.
I think that you must be looking for this otherwise you must have to write it yourself, like this
Sounds like you want Web Sockets. Don't know if there's a C library available though. I would assume there is, if you dig.
So, i am assuming that i will need to use sockets(i am a newbie to C).
The program will be for Windows(in pure C). And i shall be using these examples
http://cs.baylor.edu/~donahoo/practical/CSockets/winsock.html
My question is, instead of the client program connecting via TCP, i want the server to accept connections via a web browser i.e via HTTP.
So if the server program is running you type http://yourip:port/?gettemps and the server responds, but how do i do it?
As you might have guessed, this program will be for monitoring temps, remotely, via a web browser. But not for the CPU, for the GPU using AMD's ADL library(so yeah, only AMD cards).
The simplest option that is supported by most web servers is CGI - Common Gateway Interface.
Microsoft, of cource, has their own way of running web apps - ISAPI.
HTTP is quite a big standard, you might want to use some library such as libcurl to handle the details for you.
If you decide to code it yourself, HTTP is running over TCP so you first need to open a TCP socket at the standard HTTP port 80. Then simply listen on the socket and parse the incoming HTTP data - a great summary is given here: http://www.jmarshall.com/easy/http/.
Web browsers sends http get request to the server via tcp. If you are writing a web server from scratch than, you will need to parse data from web browser. http get request are string like for example GET /images/logo.png HTTP/1.1. So tokenize that string as it comes through tcp and get the command.
As you received your commands to the server call appropriate functions to handle your request.
Here is an great example of simple http server. You might want to make server multi-threaded as you may have multiple simultaneous users.
If you have already set up your web server to run the app on the appropriate port you can use getenv("QUERY_STRING") to access the web equivalent of command line parameters.
It would be better to call your program directly rather than just using the server to access a single default program as your example does, thus you could use http://yourip:port/yourprogram?cmd=gettemps. In this example getenv("QUERY_STRING") would return 'cmd=gettemps'.