I want to make a program that reads a serial port (V.24).
with the info from the serial port I need to split a string up, and add it to a MySQL database.
I don't know C very well, so I need some help with what functions I should use
The program has to run under windows XP, and I have to make it an service.
thanks,
Sebastian
Services are a pain to debug. I suggest writing your code as a normal application first - command line will do - and then, once it works, converting it to a service (which is a mechanical process).
In general, Windows GUI based apps in C are a PITA to write for the first time. Very finicky, very sensitive. A command line app or a service will be quite a bit easier.
I recommend reading this. As for if this will work as a service, I am not sure, but it should.
You can also look at existing open source projects, to see if you can take that source as a starting point, or if they already solve your problems.
Related
I'm looking for the simplest possible (cross-platform, but not necessarily cross-browser) code to send data from a local web page to a C (not C++) application running locally. Basically, I have an HTML page with a form and I want to send the data from that form to another process in the simplest way possible. (I know that I can read local data from a webpage relatively easily, especially now with HTML5, but writing outside of the javascript sandbox is a mystery.)
I know that browsers make this very hard to do for security concerns, and I don't want to open up my machine to attacks, but maybe I can run a very simple server inside the C application to receive the submitted data... Either way, I cannot run any standard webserver, so I need to have a C library/app that does it for me.
I've looked into .hta files (seem to only work for Windows) and some C web servers (all I've found are *nix specific). A similar question is how to transfer of data from webpage to a server c program , except that user allows the use of Java and other webserver platforms (I must use C).
UPDATE: Promising libraries: https://stackoverflow.com/questions/175507/c-c-web-server-library
Have you considered FastCGI? I have a fast CGI library written in C that might be helpful. It still needs a lot of work and I'm not sure if I would want to use in a production environment.
If you find any bugs or make any enhancements, please share them so that it can help others.
https://github.com/manvscode/shrewd-cgi
You could write a very simple web server in C, serve the page from it (avoids security issues), and post the form to it.
If you're bound to c, you'll have to go low-level and deal with all the nifty details around the sockets library. (There's a reason why people abstract that in high-level languages). Check out some example code for RPC in C with server and client here. If you can afford to bind to C, e.g. using Tcl, i would implement the server in a tcl script and bind your C functions as a Tcl command. That way you pass the content directly to your c method while avoiding to write all the sockets code low-level.
Send the desired data from web to specific port of your system (for example port X). Then run your application (e.g. APP) in background using following command:
nc -l X | ./APP
And of course you need nc package.
I'm currently writing a little commercial PHP Script which would be a VPN (PPTP) manager, in command line.
Actually, it's a socket server which is waiting for commands like "create", "suspend", "unsuspend", "changepassword"... Then it parses the PPTP files and modify them.
The thing is that I will have to give the PHP files which are so simple that they ONLY need php5-cli to be installed (and no apache, nothing else), I need to protect it from being read (actually, it's only 1 file, which is an entire class. The rest can be clear).
I want the system to be lightest as possible, that's why there is no need of GUI, web-server, curl, *sql...
I thought about IonCube, but it's very expensive and can't be used on with cli scripts because it needs a loader, which is loaded by apache. This is the problem of every encoder I think.
I thought about HipHop PHP (From Facebook), but it's hard to understand how to use (because I can compile my sources, but the user guide says how to launch our clear source with it :/ ).
So, I'm here to get help about that. I have some PHP-cli scripts, which must run in command line, which don't need a webserver to work, and I only need (as it's a commercial product) to protect my sources from reading and illegal ditribution (it will be easy to bypass the licence system). This file is simply a PHP class.
Thanks.
-- Edit --
Precisly, I want to make it paid by month, 6 months, year. If it's clear, then everybody will be able to comment the licence check, and have it for free. I love the opensource, for proof, I've written 3 classes for this project, a debug/warning/error manager with output handling (stdout/stderr/logfile) and a Socket class, which you just have to include and extends from, and you have a complete server (and you just have to implement needed functions, the server will call the "received commmand"(), and I don't want to obfuscate these 2 classes.
As to ionCube, there is an online encoder available that does a one-time encode of your script for just a few bucks, depending on the size of your codebase. If you write your own licensing mechanism, you could be able to use that. Besides, your statement about the ionclube loader is incorrect, no apache necessary, it's just a module that can be loaded in php.ini. IonCube is - in my opinion - a good choice.
Do take your time to really ask how much protection you need. A computer will always understand how to interpret your code, so eventually a human being will be able to peek inside, if he really wants to.
If the ionCube loader isn't an option on your clients, there are several 'obfuscators' for PHP out there that will probably stop the "quick peekers" from understanding the code in less than one hour. These obfuscaters won't encrypt your code, but they will make it less readable by changing all your variables, functions and class names into some arbitrary hashes, and remove all your comments and whitespace. They don't need anything on the server to be run, but in the end your PHP code will still be just the same.
I need to open a lightweight X server in C language. I figure vnc may be lightweight enough and universal in all Linux flavor and windows. Is there a C API to start vnc server? What libraries does it need?
If you know the name of the binary (executable) that you want to start, you can probably just use system() to start it. Assuming the binary is in /usr/bin/vncserver:
system("/usr/bin/vncserver");
Note though, as pointed out in a comment, that your question is fairly confused. A VNC server is not an X server. It's perfectly possible to run a VNC server without running X "inside" it. So starting a VNC server will most likely not help with your problem. I suggest you post a new question with a more clear description of what you're trying to achieve, this sounds a lot like you're "jumping" to a solution.
I want to make project for my final year in college.
So someone suggested me to make Remote Desktop in C.
Now I know basic socket functions for windows in C i.e. I know how to make
echo server in C.
But I don't know what to do next. I searched on internet but couldn't find
something informative.
Could someone suggest me how to approach from this point..any tutorial...or any source ?
I think this is do-able. For a college project, you don't need to have something as complex and as full-featured as VNC. Even demonstrating simple keyboard and mouse control and screen feedback would be enough, in my opinion, and that's well within reach.
If you're doing everything from scratch and using Win32, you can get the remote screen using the regular "printscreen" example all around the internet.
http://www.codeproject.com/KB/cpp/Screen_Capture__Win32_.aspx has it, for one. You can then compress the image with a third-party library, or just send it raw; this wouldn't be very efficient but it would still be a viable demonstration.
Apart from capturing the screen data remotely and showing it in the local window, you'll need to listen for local window messages for mouse and keyboard events, send them to the remote host, and then play them back. http://msdn.microsoft.com/en-us/library/ms646310%28VS.85%29.aspx will probably do that for you.
Check tightvnc TightVNC is a free remote control software package. The source code is also available.
For sending the image of the screen I would probably use rtp. The JRTPLIB is really handy for that.
And yes, as KevinDTimm says, an echo server is the very easiest part.
KevinDTimm may well be right, writing an RDP client would a fairly significant undertaking. To give you some idea, the current spec, available at the top of this page, is 419 pages long and includes references to several additional documents for specific aspects of RDP like Audio Redirection and Clipboards.
If it's possible, I'm interested in being able to embed a PostgreSQL database, similar to sqllite. I've read that it's not possible. I'm no database expert though, so I want to hear from you.
Essentially I want PostgreSQL without all the configuration and installation. If it's possible, tell me how.
Run postgresql in a background process.
Start a separate thread in your application that would start a postgresql server in local mode either by binding it to localhost with some random free port or by using sockets (does windows support sockets?). That should be fairly easy, something like:
system("C:\Program Files\MyApplication\pgsql\postgres.exe -D C:\Documents and Settings\User\Local Settings\MyApplication\database -h 127.0.0.1 -p 12345");
and then just connect to 127.0.0.1:12345.
When your application quits, you can always send a SIGTERM to your thread and then wait a few seconds for postgresql to quit (ie join the thread).
PS: You can also use pg_ctl to control your "embedded" database, even without threads, just do a "pg_ctl start" (with appropriate options) when starting the application and "pg_ctl stop" when quitting it.
You cannot embed it, nor should you try.
For embedding you should use sqlite as you mentioned or firebird rdbms.
Unless you do a major rewrite of code, it is not possible to run Postgres "embedded". Either run it as a separate process or use something else. SQLite is an excellent choice. But there are others. MySQL has an embedded version. See it at http://mysql.com/oem/. Also several java choices, and Mac has Core Data you can write too. Hell, you can even use FoxPro. What OS you on and what services you need from the database?
You can't embed it as a in process type thing like sqlite etc, but you can easily embed it into your application setup using Inno setup at http://www.innosetup.org. Search their mailing list archive and you will find someone did most of the work for you and all you have to to is grab the zipped distro and you can easily have postgresql installed when the user installs your app. You can then use the pg_hba.conf file to restrict the server to local host only. Not a true embedded DB, but it would work.
PostgreSQL is intended to run as a stand-alone server; it's probably possible to embed it if you hack at it hard and long enough, but it would be much easier to just run it as intended in a separate process.
HSQLDB (http://hsqldb.org/) is another db which is easily embedded. Requires Java, but is an excellent and often-used choice for Java applications.
Anyone tried on Mac OS X:
http://pagesperso-orange.fr/bruno.gaufier/xhtml/prod_postgresql.xhtml
http://www.macosxguru.net/article.php?story=20041119135924825
(Of course sqlite would be my embedded db of choice as well)
Well, I know this is a very very very old post, but if anyone has nowadays this question, I would refer to:
You can use containers running Postgres. Here's a post that could be helpful, doing something along this line using R:
https://rsangole.netlify.app/post/2021/08/07/docker-based-rstudio-postgres/?utm_source=pocket_mylist
Take a look at duckdb https://duckdb.org/docs/installation/ It is relatively new and still needs to mature. But it works pretty much like an embedded database ("In-process, serverless"), with bindings for several languages (Python, R, Java, ...)