Starting serverside print job via PHP - c#

This is most likely not an easy one but here is the situation:
I have written a C# command line application which:
creates a PDF using ITextSharp
writes it to disk
uses Acrord32.exe (this is Acrobat Reader) via System.Diagnostics.Process in order to silently print the generated PDF
If I build my solution and double click the pdfGen.exe, it works as expected. The PDF is created and printed.
Now, my app has to be deployed on a internal server with Windows Vista running IIS 7. This server has some PHP webapp running. And it will be called via PHP using shell_exec() so that the resulting PDF will be printed on the printer attached to the server.
So my PHP page looks basically like this:
shell_exec('/path/to/pdfGen.exe');
But here things go wrong. What happens is according to task manager etc.:
pdfGen.exe starts
the PDF is created
Acrord32.exe starts
pdfGen.exe hangs forever (and so does the PHP script) and nothing is printed
I am pretty sure it is some permission related problem. I already gave IIS_IUSRS access to the default printer, and to the directory where Acrord32.exe is located. But still, no printing. However, if I start my pdfGen.exe manually it works.
Any idea what I am missing?
EDIT:
I am not bound to use Acrobat Reader in order to print the PDF. If there is another way in order to silently print the created PDF serverside, I would not mind at all.

In order to check what is going on, try to run
the process monitor from Sysinternals and filter the events to the adobe acrobat process. You will see the system calls of acrobat and it will allow you to know more or less what is going wrong.

I know a small improvement to your solution: SumatraPDF has a nice command-line interface that can be used to auto-close Sumatra after printing.
I used PHP "system" or "exec" functions to execute a batch file to open SumatraPDF:
sumatrapdf.exe -print-to-default -exit-on-print <path_to_PDF_file>
(you can also specify the printer name to print on)

that's an interesting program.
IIS_IUSRS
seems to have no permission to print, try adding IIS_IUSRS to Print Operators Group / grant Print permission to the user.

Shell_exec() is almost intended for shell commands (ls/dir, cp, etc.)
Have you tried to use exec() instead of shell_exec() ?

Thanks all for your comments. Unfortunately this "php start printjob" thing was part of a larger project that was cancelled today because of, well... I dont know... political reasons. Guess the project is pretty much dead.
Anyway, I tried myself a few more times in the last days and could not get it to work with IIS. My solution that I implemented and tested already: remove IIS, install a XAMPP or WAMPP package with a local apache and PHP that runs with admin access rights.
This did the trick. I used pclose(popen('...command...', 'r')); in PHP in order to start the .exe and so that PHP does not wait until the PDF is finished. It all worked great.
Here is my C# code which starts the print job using Acrobat Reader
public void Print(string pathname, string acrobatDirectory)
{
var proc = new Process
{
StartInfo =
{
Arguments = String.Format("/t \"{0}\"", pathname),
FileName = acrobatDirectory,
UseShellExecute = false,
CreateNoWindow = true,
RedirectStandardOutput = false,
RedirectStandardError = false,
}
};
proc.Start();
}
The first argument is the path to the PDF that should be printed, the second parameter is the absolute path to the AcroRd32.exe.
The only problem left was that AcroRd32.exe was started, printed and never got closed again. So every printjob started a new instance of AcroRd32.exe (I am using Acrobat Reader 9.0). So if you printed 10 times, 10 acrobat reader instances were created.
What I did was starting the print job, then waiting X seconds, hoping that the printer was finished and then killing all AcroRd32.exe instances:
public void Print(string pathname, string acrobatDirectory)
{
Debug.WriteLine("Printing...");
Printer.Print(pathname, acrobatDirectory);
Thread.Sleep(30000);
try
{
Debug.WriteLine("Trying to kill runnung AcroRd32.exe's ");
FindAndKillProcess("AcroRd32");
}
catch (Exception)
{
Debug.WriteLine("AcroRd32.exe could not be killed...");
}
}
private bool FindAndKillProcess(string name)
{
foreach (Process clsProcess in Process.GetProcesses())
{
if (clsProcess.ProcessName.StartsWith(name))
{
clsProcess.Kill();
return true;
}
}
return false;
}
This worked out quite well.
Note that the above (killing all AcroRd32.exe and running PHP with admin privilegs) was only doable because: The whole thing is only used by one user at a time and has a very limited area of use.
It should be used on a touchscreen application deployed at the clients POS. A salesman would use the PHP app in order to configure a product, and then PHP would call my .exe which would create and print a PDF in the background. The printed document is then handed to the client. So security etc. was not really a concern in this case.
If anyone has a solution in order to use it with IIS, I am still willing to accept it as an answer.

Related

DirectX app unable to load through Process.Start on Windows Server 2012 R2, works fine through CMD or on local machine

I have an app that runs DirectX 11 that plays a scene and generates an mp4.
I am trying to launch it through Process.Start so that I can manage the process and force it to timeout if it crashed or doesn't close correctly.
When I test the function on my local Win10 machine it works perfectly, and when I run it through CL or a .BAT file on the WinServ2012R2 machine it works perfectly too.
However when I try to run it through the Process.Start function on the server machine it fails to open DirectX
var startInfo = new System.Diagnostics.ProcessStartInfo($"{AppLocation}", $"{Parameters}")
{
WindowStyle = System.Diagnostics.ProcessWindowStyle.Normal,
UseShellExecute = false,
RedirectStandardOutput = true,
CreateNoWindow = false,
WorkingDirectory = $"{DirectoryName}",
Verb = "runas"
};
var loop = 0;
while (!System.IO.File.Exists($"{FileLocation}"))
{
loop++;
using (var p = System.Diagnostics.Process.Start(startInfo))
{
Logger.Info("Process Running....");
if (!p.WaitForExit(300000))
{
p.Kill();
}
if (loop >= 5)
break;
}
}
Edit: The DirectX error is: DXGI_ERROR_NOT_CURRENTLY_AVAILABLE
0x887A0022
It’s probably something about the environment.
If the parent process is a normal Win32 console or GUI app running inside a desktop of that server, put something like Sleep( 60000 ); in the first line of your main() or WinMain function, and use Process Explorer to find differences between manual launch which works, and programmatic launch which fails. Check the “Image”, “Security” and “Environment” tabs of the processes.
If the parent process is a system service, it’s more complicated. Services generally run under another user account and you gonna need some setup to allow the service, or a child process launched by the service, to access GPU.
Another possible reason is anti-virus or anti-malware breaking things.
P.S. Note you have minor bugs in your code.
One thing, when you detect timeouts, Process.Kill is asynchronous, you need to wait afterwards.
Another one, you specifying RedirectStandardOutput = true but you don't consume that stream. If the child process prints a lot of text it will eventually stall waiting for the parent process to consume the data buffered in that pipe. If you don’t care about output, don’t redirect these streams. If you do care, redirect and consume the data as soon as it printed, either on a separate thread or with async/await.

Diagnostics.Process doesn't open PDF file using adobe reader

I'm having a problem while trying to open a PDF file using Process.Start().
The program runs the process as a background process but no adobe reader window show up. A solution i found was to use chrome.exe, but my client want to open on adobe-reader, as it's the default windows program.
(I have also trying without forcing "AcroRd32.exe" and passing the full path of "AcroRd32.exe". Same problem).
Anyone solved this?
My code:
var p = new Process
{
StartInfo = new ProcessStartInfo(#"AcroRd32.exe", #"D:\Tests\81803130000326__.pdf")
};
p.Start();
Background Processes:
I also have checked this question: Process.Start(/* path to pdf */) doesn't work with Adobe Reader on Windows 8
Edits
EDIT INFO: Forgot to say i'm running Windows 10 with Adobe Reader DC 2018.009.20044
EDIT 2: Found a "problem" of Adobe Reader DC. It mantains a level of security that doesn't let me run it as administrator (don't ask me why). Check this link for more information: https://forums.adobe.com/thread/1955530
Now I'll try to find a solution to run it without administrator privileges, or ask my client to uncheck the checkbox
Solution
So, I've found a solution for my problem. The Adobe Reader, since version 10.0, has a "Protected Mode" setting. I wrote a code to change that setting in the registry, so the user won't need to do that. Link: https://www.adobe.com/devnet-docs/acrobatetk/tools/AppSec/protectedmode.html
I hope it helps others in the future!
Solution Code:
var registroAdobe = Registry.LocalMachine.OpenSubKey(#"Software\Policies\Adobe\Acrobat Reader\DC\", true);
registroAdobe.SetValue("bProtectedMode", 0);
This works for Acrobat Reader DC. You can run through "Software\Policies\Adobe\" Products and Versions if you need it.
Actually, I found that this didn't work on my computer, but it led me to look deeper.
I found my solution to be:
var regAdobe = Registry.CurrentUser.OpenSubKey(#"Software\Adobe\Acrobat Reader\DC\Privileged", true);
regAdobe.SetValue("bProtectedMode", 0);
Very similar, but ended up having to edit the user setting rather than the local machine's setting.
Cheers!
You can directly use System.Diagnostics.Process.Start("") to open with default pdfreader program on respective client system.

Printing any file type

I'm creating a service that will monitor a specific folder and print any file that is put in this folder. I'm having difficulties with the various file types that could be sent to the folder to be printed.
My first attempt is with Microsoft Office files. What I'm trying to do is start the office to print the file. It's more like a catch, I'm not really using a library or anything like it.
So far this approach would work, but when no Office application has ever started on the machine the Office asks for the user initials. So, in this case my application would just not work, since I'm doing this programatically.
ProcessStartInfo info = new ProcessStartInfo(myDocumentsPath);
info.Verb = "Print";
info.CreateNoWindow = true;
info.WindowStyle = ProcessWindowStyle.Hidden;
Process.Start(info);
Right now I am trying with Microsoft Office files, but I will apply the same approach for other types as well.
There is anyway to get around the Initials required by the first Office run?
Or any better approach to my problem?
Any help is appreciated, thanks in advance.
There's not really anything that you can do; for the application which will print each type of file that you're going to support, you need to make sure the application is configured correctly.
This means that for office (since it is run as an out-of-process COM server) you should run it under the account that is performing the printing so you can enter the initials and won't be prompted for it when the server attempts to print it.
The same for every other application (assuming the application is executed to print it), it needs to be run as the account the process is going to be run under and configured correctly.
Use Winternals's regmon registry activity monitor to figure out where Office stores the initials in the windows registry, then write these keys prior to printing.

Failing to programatically overwrite a file in an IIS Virtual Directory/Application (file is always locked)

At first I thought I'm facing a very simple task. But now I realized it doesn't work as I imagined, so now I hope you people can help me out, because I'm pretty much stuck at the moment.
My scenario is this (on a Windows 2008 R2 Server):
A file gets uploaded 3 times per day to a FTP directory. The filename is always the same, which means the existing file gets overwritten every time.
I have programed a simple C# service which is watching the FTP upload directory, I'm using the FileSystemWatcher class for this.
The upload of the file takes a few minutes, so once the File Watcher registers a change, I'm periodically trying to open the file, to see if the file is still being uploaded (or locked)
Once the file isn't locked anymore, I try to move the file over to my IIS Virtual Directory. I have to delete the old file first, and then move the new file over. This is where my problem starts. The file seems to be always locked by IIS (the w3wp.exe process).
After some research, I found out that I have to kill the process which is locking the file (w3wp.exe in this case). In order to do this, I have created a new application pool and converted the virtual directory into an application. Now my directory is running under a seperate w3wp.exe process, which I supposedly can safely kill and move the new file over there.
Now I just need to find the proper w3wp.exe process (there are 3 w3wp.exe processes running in total, each running under a seperate application pool) which has the lock on my target file. But this seems to be an almost impossible task in C#. I found many questions here on SO regarding "Finding process which locked a specific file", but none of the answers helped me.
Process Explorer for example is exactly telling me which process is locking my file.
The next thing I don't understand is, that I can delete the target file through Windows Explorer without any problem. Just my C# application gets the "File is being used by another process" error. I wonder what's the difference here...
Here are the most notable questions on SO regarding locked files and C#:
Win32: How to get the process/thread that owns a mutex?
^^
The example code here does actually work, but this outputs the open handle IDs for every active process. I just can't figure out how to search for a specific filename, or at least resolve the handle ID to a filename. This WinAPI stuff is way above my head.
Using C#, how does one figure out what process locked a file?
^^
The example code here is exactly what I need, but unfortunately I can't get it to work. It is always throwing an "AccessViolationException" which I can't figure out, since the sample code is making extensive use of WinAPI calls.
Simple task, impossible to do? I appreciate any help.
EDIT
Here are some relevant parts of my server code:
Helper function to detect if a file is locked:
private bool FileReadable(string file, int timeOutSeconds)
{
DateTime timeOut = DateTime.Now.AddSeconds(timeOutSeconds);
while (DateTime.Now < timeOut)
{
try
{
if (File.Exists(file))
{
using (FileStream fs = File.Open(file, FileMode.Open, FileAccess.Read, FileShare.None))
{
return true;
}
}
return false;
}
catch (Exception)
{
Thread.Sleep(500);
}
}
m_log.LogLogic(0, "FileReadable", "Timeout after [{0}] seconds trying to open the file {1}", timeOutSeconds, file);
return false;
}
And this is the code in my FileSystemWatcher event, which is monitoring the FTP upload directory. filepath is the newly uploaded file, targetfilepath is the target file in my IIS directory.
// here I'm waiting for the newly uploaded file to be ready
if (FileReadable(filepath, FWConfig.TimeOut))
{
// move uploaded file to IIS virtual directory
string targetfilepath = Path.Combine(FWConfig.TargetPath, FWConfig.TargetFileName);
if(File.Exists(targetfilepath))
{
m_log.LogLogic(4, "ProcessFile", "Trying to delete old file first: [{0}]", targetfilepath);
// targetfilepath is the full path to my file in my IIS directory
// always fails because file is always locked my w3wp.exe :-(
if(FileReadable(targetfilepath, FWConfig.TimeOut))
File.Delete(targetfilepath);
}
File.Move(filepath, targetfilepath);
}
EDIT2:
Killing the w3wp.exe process while clients are downloading the file would be no problem for us. I'm just having a hard time finding the right w3wp.exe process which is locking the file.
Also, my client application, which is downloading the file on the clients, is checking the HTTP HEAD for the Last-Modified date. The client is checking the date every 10 minutes. So it is possible that the file is being locked by IIS because there are clients continously checking the HTTP HEAD for the file. Nonetheless, I don't understand why I can manually delete/rename/move the file through windows explorer without any problems. Why does this work, and why does my application get a "Locked by another process" exception?
One problem I've run into is that a file exists while it is still being written, which means it would be locked as well. If your FileReadable() function were called at this time, it would return false.
My solution was to, in the proc which writes the file, write the file to, say, OUTPUT1.TXT, and then after it is fully written and the FileStream closed, rename it to OUTPUT2.TXT. This way, the existence of OUTPUT2.TXT indicates that the file is written and (hopefully) unlocked. Simply check for OUTPUT2.TXT in your FileReadable() loop.
Everybody say...
"Do it a better way"
Nobody say how!!!
Here's how. Because you mentioned 'My Client Application,' there is a key opportunity here that you would not have if you didn't have control over the apps reading the file.
Just use new filenames each time.
You have control of the program reading and writing the files. Put an incrementing # in the filesnames, have the client pick the biggest # (Actually the latest date, then your numbers can wrap around). Have the writer program clean up old files if it can; if not, they won't hurt anything. IIS will eventually let go of them. If not, just open up explorer every week and do it yourself!
Other keys that make this work are the low frequency of updates (files won't build up too bad), and the fact that the FTP+webserver are on the same drive (Otherwise the MOVE is not atomic and clients could get a half-copied file. Solution if FTP drive is different would be to copy to a temp drive on the webserver then move).
but what if you can't change the client or it has to read just one name?
Front-end it with a script. Have the client hit an ASPX that sets the right HTTP headers and has the 'pick the right file' logic, and spits out the file contents. This is a very popular trick pages use to write images stored on a database out to the browser, while the img tag appears to read from a file. (google along that lines for sample code).
sounds like a hack, it's not. Modern lockless memory cache systems do a similar thing. It is impossible for a lock or corruption to occur; until the 'write' is complete, readers see the old version.
plus, it's simple, everybody from a script kiddie to a punchcard vetern will know exactly what you're up to. Go low-tech!
You're troubleshooting a symptom of the problem not a fix for the root cause. If you want to go down that path here is the code to kill processes http://www.codeproject.com/Articles/20284/My-TaskManager - but the better idea would be to do it properly and work out whats wrong. I suggest in the Catch Exception of FileReadable:
catch (Exception ex) {
if (ex is IOException && IsFileLocked(ex)) {
//Confirm the code see's it as a FileLocked issue, not some other exception
//its not safe to unlock files used by other processes, because the other process is likely reading/writing it.
}
}
private static bool IsFileLocked(Exception exception)
{
int errorCode = Marshal.GetHRForException(exception) & ((1 << 16) - 1);
return errorCode == 32 || errorCode == 33;
}
Turn off any Anti-Virus software and re-test
Increase the polling timeout duration to see if its just a timing thing
Check the FTP logfile and see the status for the disconnected client and compare the status code with the ones here.
I don't see in your sample code where you are closing your file stream. Keeping the file stream open will keep a lock on the file. It would be a good idea to close the stream. You probably don't want to be killing your w3wp.exe process, as others here have mentioned.
restarting IIS can unlock the file taken by w3wp.exe.
cmd (run as administrator) -> iisreset /stop -> update/delete file in
windows explorer -> iisreset /start

how to program to integrate with filezilla in C#.[sftp]

I would like to integrate FileZilla with my application written in C#.
please someone show me sample code or web site that shows sample code.
although i found article on web, and that article was saying
"application is integrated with FileZilla is so slow".
but i don't know if i can stand that late or not.
so i would like to challenge.
To support FTP/SFTP or any other protocol in C# you can do it in 3 ways:
1. NEW APP PROCESS - Start an app that does the FTP communication in separate process, and be able to control what file to download, where to save it and to tell the app to terminate when download is finished. This way, you can use FileZilla only if it lets you pass certain parameters in command line, like the URI of the resource you want to transfer through FTP/SFTP, and the path where the file should be saved to. And as I can see HERE this could work.
To start the process and pass it command line arguments in C# you would do something like this:
static void StartNewProcess(string app, string args)
{
ProcessStartInfo startInfo = new ProcessStartInfo();
startInfo.FileName = app; //full app path
startInfo.Arguments = args; //command line arguments
startInfo.CreateNoWindow = true; //dont create app window
startInfo.WindowStyle = ProcessWindowStyle.Hidden; //hide app from taskbar
Process.Start(startInfo);
}
Now you can execute FileZila app, pass it args containing file URL and let it do its job... But you cant know how long will it take to download the file, when the download is ended, do you need to log in to get it...
2. EXISTING CLASS LIBRARY - Include a Class Library that is written by someone else, that does the job. This way you are in TOTAL control of the process. And as many other suggested, this would be a perfect way for you. Many answers here contain good class libraries that you can use and be happy with the results.
3. HOME-MADE CLASS LIBRARY - Open RFC 959, read it all and write your code... (Now 2. sounds better, doesn't it? :D)
Filezilla is a GUI FTP client, you can't use it to "script" SFTP operations (it only accepts a very limited set of command line arguments).
You must seek a third party C# component or write one yourself (not recommended) to do the job.
To support FTP or SFTP from your C# application, you could use an external library like the one from Chilkat http://www.chilkatsoft.com/ftp-2-dotnet.asp. I use it and it works great!
In theory, you could also implement the FTP protocoll using socket connections by yourself, but you should save yourself that trouble -> don't reinvent the wheel...
I recommend using SharpSSH, if you need to send files via SSH/SFTP in your application.

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