I have a particular problem, I have some program that I cannot modify but that provides some functionality I'd like to use inside office. So I am writing a plugin for Office that takes my document, executes the program on the background, puts the document on the stdin. The program writes to the stdout, and I take that back to my program to post process that.
This all works fine except that the program asks for a password which I don't want to put on stdin. The tool has a way to read the password from any other input stream but it needs the number of the file-descriptor it should read from.
So here is my question: how do I (within the .net environment) open a stream on a file descriptor with a number that I can give as parameter to this program? Ideally I want to write something like:
process.start("start-program --password-fd " + x);
stream = new StreamWriter(x);
stream.write("secritpwd");
ect.. (but then magically corrected so it will work ;) )
I hope someone can help me.
Thanks
I'm not sure exactly what this app means by "file descriptor", but you may be able to pass the handle of an inheritable anonymous pipe. See AnonymousPipeServerStream. (This assumes you're on at least .NET 3.5.)
The basic outline would be something like this:
Instantiate an AnonymousPipeServerStream.
Pass the pipe handle (pipeServer.GetClientHandleAsString()) as a command-line parameter to your C executable.
Write to the AnonymousPipeServerStream.
File descriptors aren't part of Windows - they're part of the C runtime library. You would have to write a DLL in C or C++ to do your file I/O, then call it from your C# program. Get the file descriptor number from the C DLL to pass to your other code.
Maby this links will help you to start and to get the logic from:
How to use OpenFileById to open a file
Opening pipe connection to a file descriptor in C#
OpenFileById Function
Related
I'm trying to retrieve a file from the Process.Start()-Method.
Following scenario is given:
I obtain a link from a third party program. This link can be a UNC-path, direct link to PDF/JPG/TIF-files, such as "www.certainServer.de/test.pdf", as well as link to programs on the server, which return a special file type, such as "www.certainServer.de/test.aspx".
I open the file like this
Process.Start(_path)
If the link is like "www.certainServer.de/test.aspx" the returned file is automatically downloaded to the deposited download folder.
Is there a opportunity to retrieve the downloaded file or the path to the downloaded file?
The returned Process-object from the Process.Start()-Method doesn't seem to be helpful.
Process.Start does not necessarily download a file. It simply starts a process. You just as easily could start Notepad, which has no side effects (except, of course, what you do with notepad once it's started). If the process you start (in your case, calling a web page) has external effects, the process engine knows nothing about it.
It sounds like you know where the file is supposed to be deposited, so you could use something like a FileSystemWatcher to be alerted when a new file is added (which doesn't necessarily mean it came from your process, though) or get a list of files before and after the process is run.
But there's nothing inherent to System.Process to definitively know what that process did.
Another option might be to call the URL from your code (using WebClient or something similar) and capturing the result (which might be a file, or just a web page, depending on the URL). It's not as general as starting a process and letting the default browser handle the download, but it would capture the results more definitively.
I have a program that has c/c# abilities, and I have python. I want that program to update a text file, almost in milliseconds, and have the python to read that text file in milliseconds as well. How can I go achieve this?
Is it possible for a text file to be updated live by another program and be read live by python? Is there any alternative way to do this instead of relying on text file.
Basically what I want to do is a bunch of computations on live data from that program using python and send back those computations to the program in form of commands.Can a file not be closed and reopened and yet updated in the memory?
If you start the C/C# process from python with subprocess.Popen then your two programs can communicate via the stdin and stdout pipes:
c_program = subprocess.Popen(["ARGS","HERE"],
stdin = subprocess.PIPE, # PIPE is actually just -1
stdout= subprocess.PIPE, # it indicates to create a new pipe
stderr= subprocess.PIPE #not necessary but useful
)
Then you can read the output of the process with:
data = c_program.stdout.read(n) #read n bytes
#or read until newine
line = c_program.stdout.readline()
Note that both of these are blocking methods, although non blocking alternatives exist.
Also note that in python 3 these will return bytes objects, you can convert into a str with the .decode() method.
Then to send input to the process you can simply write to the stdin:
c_program.stdin.write(DATA)
Like the read above, in python 3 this method expects a bytes object. You can use the str.encode method to encode it before writing it to the pipe.
I have extremely limited knowledge of C# but from limited research it seems that you can read data from System.Console.In and write data to System.Console.Out, although if you have written programs in C# that run in a terminal, the same methods used to write data to the screen and read input from the user will work here too. (you can imagine the .stdout as the terminal screen and data python writes to .stdin the user input)
so what I'm trying to do is open a file (well, actually two folders, but I figure I'll start with a single file for now) using a third party comparison tool called UltraCompare. I'm working in a C# website project in Visual Studio 2010 (Express edition). I've seen how to open a file using a different program, here: Open a file with Notepad in C#.
Problem is, this only lets you open it using the default program for that file type. But I want to open it in a specified program. For example, a text file should open in UltraCompare, not notepad. Here's the code which does this:
string textBoxContents1 = TextBox1.Text;
Process.Start(textBoxContents1);
The textbox on the webform accepts a string, in which the user types the file's full path (not the most user-friendly design I know, but I'm not sure how to allow them to browse for a folder using a GUI interface in asp.NET). The file is then passed into the Process.Start() method, which opens it using the default program for that file type.
Is there any way to modify this to make it open using UltraCompare??
You can specify the program you want to open the file in:
Process.Start("yourprogram.exe", textBoxContents1);
Update
To open two files in Ultracompare, you'd probably do something like that:
Process.Start("yourprogram.exe", "file1.txt file2.txt");
Keep in mind that the second parameter of Process.Start method are the arguments passed to the program.
I said this is probably going to work because I assumed to be very likely that Ultracompare expects 2 arguments, but this might not be the case.
Quick question: Are you trying to do this for the client machine? Hope not
And I guess it looks into the PATH variable for finding your exe
I have a question about converting pdf to swf in real time in c# code behind, so that i can use FlexPaper to display the pdf document. I have tried to find any solution to generate the swf, but unluckily, I only got a method which use "pdf2swf.exe" by calling "System.Diagnostics.Process" and just like a call in command prompt in the code behind.
So, is this a proper approach? In order to let code behind to see the exe file, I have to place the exe file within the Web Dir branch, and this file may go to the public.
Can anyone can give me an advice on how to convert pdf to swf in proper way?
thanks
jack
I'd split the process that converts the pdf and shows the created swf.
Let a service of some sorts pick up pdf files in a special directory and convert them to a special directory. This way the asp.net process does not have to be able to start processes and write data. It just has to place the file in the correct folder.
Calling external processes can create dangerous situations if you don't handle error codes correctly. Do you catch convertion erros in any way?
I work for a company that makes application's in C#.
recently we got a customer asking us to look in to rebuilding an application written in PHP.
This application receives GPS data from car mounted boxes and processes that into workable information.
The manufacturer for the GPS device has a PHP class that parses the received information and extracts coordinates. We were looking in to rewriting the PHP class to a C# class so we can use it and adapt it. And here it comes, on the manufacturers website there is a singel line of text that got my skin krawling:
"The encoding format and contents of the transmitted data are subject to constant changes.
This is caused by implementations of additional features by new module firmware versions which makes it virtually impossible to document it and for you to properly decode it yourself."
So i am now looking for a option to use the "constantly changing" PHP class and access it in C#. Some thing link a shell only exposing some function's i need. Except i have no idea how i can do this. Can any one help me find a solution for this.
I know it's a really hacky solution, but if you need a bit of PHP code that you don't want to have to repeatedly port to C# each time, you could try the following approach, although it means that you would need the php command line tool on the target machine.
First step is to have a php script that continously reads data off stdin, decodes it using this special class from the vendor, and writes the result out to stdout. Really simple example:
<?php
include("VendorDecodingClass.php");
while(true)
{
$input = fgets(STDIN); //read off of the stdin stream
//can't remember if this is valid, but somehow check that there is some data
if($input)
{
//pass it off to the vendor decoding class
$output = VendorDecoding::decode($input);
fwrite(STDOUT, $output); //write the results back out
}
//sleep here so you don't suck up CPU like crazy
//(1 second may be a bit long tho, may want usleep)
//Edit: From Tom Haigh, fgets will block, so the sleep isn't necessary
//sleep(1);
}
?>
Anyway, once you have that in place, in your C# application, right at the start, create a new Process to run that script and then save the Process instance somewhere, so you can reference the STDIN and STDOUT at a later point. Example:
ProcessStartInfo procStartInfo = new ProcessStartInfo("php", "yourscript.php");
procStartInfo.RedirectStandardOutput = true;
procStartInfo.UseShellExecute = false;
procStartInfo.CreateNoWindow = true;
Process proc = new Process(); //store this variable somewhere
proc.StartInfo = procStartInfo;
proc.Start();
Then, when you want to decode your data, you just write to the stdin of the php process you created, and wait for a response on the stdout. Using the stdin/stdout approach is a lot more efficient than creating a new process each time you want to decode some data, because the overhead of creating that process can be noticeable.
proc.StandardInput.WriteLine(somedata); //somedata is whatever you want to decode
//may need to wait here, or perhaps catch an exception on the next line?
String result = proc.StandardOutput.ReadLine();
//now result should contain the result of the decoding process
Disclaimer here, I haven't tested any of this code, but that is the general gist of how I might do it.
Something else I just thought of, you will want some mechanism for terminating that PHP process. It may be OK to use Process.Kill, but if the decoding does any file IO, or anything critical you may want to send an interrupt signal to the php script somehow.
I assume the php script is on your machine and returns usefull data. The first -not very elegant solution- that pops into my mind is the following:
Make sure your machine has the php commandline installed, so that you are able to run the php script from commandline. To execute a commandlinetool from C# see code for that here. The returned data now probably needs to get processed my your C# program.
I have never tried this and do not know anyone that has, but I remember comming across this sometime ago and thought I would throw it out there as a possible option for you.
Phalanger is a compiler project that compiles PHP code to IL, so you can use that then have a managed assembly that you reference from your code directly.
If the format is a regex you can try to put it in an application setting file (not resources, these are compiled WITH the application, you can't change them without recompiling the app).
Application settings are not changeable by the user but you can do that by editing the XML.
Or you can set the settings to user mode and then you can change the format from inside your application code.
Why don't you just launch the PHP script from C#, have it output its results to a file and then use that file as input for your C# program?
Personally, I would setup a PHP web service with a proper and stable API that the C# project can access, implement the manufacturers supplied PHP class in the web service and let it be.