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.
Related
I'd like to use terminal for all of my normal git and compiling and running processes (my school has a server that is linked to my repo on bitbucket), but I really don't like terminal-based text editing software such as Emacs and Vim. Is it possible to open and edit files from the terminal using a GUI based text editor? The reason I'm asking is because the terminal is the only way I can access the server files. Thanks in advance!
Aw, but vim is the best! :) Well, you can use nano, which is friendlier. Or, if you insist: if you are using SSH to connect to the server (and the server has an X server running !) then you can look into the ssh -X option to view X windows on your remote machine.
Oh and you could look into scp command as well (behaves almost just like regular cp, but the destination is on another host). That way you could edit on your machine, then copy it via SSH (although you'd want to be careful when copying files directly to the server filesystem)
Edit: Also, if you really don't like using the terminal (why though? (-: ), some file managers allow you to get the same functionality of the previous commands purely via GUI (for example).
You've left out some important information that someone would need to know to answer your questions. The other posters have made some assumptions.
You've mentioned this "terminal", but it's not clear exactly what that is, or how you're getting to it. What kind of computer do you have in front of you? What shell is running in that terminal? Is the shell running on your local computer, or have you remotely connected to a server and running that shell on the remote computer?
Based on what you said, I have a feeling you're making a remote connection to a server, perhaps using ssh. You likely have either a Windows or Mac PC in front of you. In those circumstances, running a GUI editor like Eclipse is possible, but likely not practical. You would have to have Eclipse installed on that remote computer, and you would be displaying the Eclipse window on your local computer using the X11 protocol. That takes a lot of bandwidth.
If my assumptions are correct, my recommendations depend on how long you expect you're going to want to stay familiar with this environment. If you intend to do this sort of work forever, then you should learn vi and Emacs to the best of your ability. As someone who's been using Emacs likely longer than you've been alive, I'd recommend you learn it, but vi is also a critical skill.
UNIXY systems provide open or gopen, depending on your OS, that should get the job done. From the man page:
By default, gopen will open filename with the application currently assigned to the file's extension. But by specifing the -a flag on the command line you can tell gopen to open the file with another application.
This means that you can use it to open files in your preferred editor
with a line like
gopen -a Eclipse file
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 have a linux server has an ad-hoc wireless network for clients to connect to. Once connected I want users to always be redirected to it's own web server no matter what URL they type in. The large solution would be to set up a full DNS server (with BIND or equivalent) but that seems like overkill. All I need is a simple program that will listen for any DNS request and always respond with the same IP address.
I looked around for one but couldn't seem to find one. It would preferably be written in C or Perl as I don't really want to install any other scripting languages.
Use Net::DNS::Nameserver and write your own reply handler.
For C, look at:
How to Build a custom simple DNS server in C/C++
Create custom DNS name server in C
I would suggest using dnsmasq. It's more full-featured than you absolutely need, but it's very well-written, small, and easy to install, and the only configuration you would need to give it is --address='/#/1.2.3.4' to tell it to answer all queries (that don't match some other rule) with the address 1.2.3.4. dnsmasq is well-known and maintained and probably a more robust server than Net::DNS::Nameserver.
I've used fakedns.py when reversing malware. It may be too limited for your situation.
As I answered in the other related question, I wrote a basic DNS server in C++ for a job interview under BSD license.
I think the code was pretty clean, though I didn't made unit tests :-(
I tested it with dig, and it took about a week understanding DNS protocol + implementing + documentation.
If anyone would want to extend it, I guess it would not be very difficult.
Because I think it only supported inverse queries, as that was asked in the exercise.
The code could be found here:
http://code.google.com/p/dns-server/
It was migrated to: https://github.com/tomasorti/dns-server
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, ...)