I'm having trouble getting this to work and hope that one of you have done this before in .NET. The code I have seems like it should work, but unfortunately I can't directly test it because it's being executed by a subversion hook script (post-commit.bat)... Essentially, my program is like a wrapper for svn export. I'm thinking that what's happening is svn is prompting for confirmation to accept the SSL certificate, but since it's an automated process there is no user to respond. As a result, I'm attempting to simulate the user's response by writing to svn's stdin stream.

I'm starting svn with a System.Diagnostics.ProcessStartInfo instance and System.Diagnostics.Process.Start() as follows...

I think it should work to WriteLine() a response to the StandardInput StreamWriter of the svn process.

I've added log messages before and after the above code where I write to the stdin stream. Both are logged, but nothing more. If svn fails to start, times out, or exits with a non-zero exit status that should be logged. If svn succeeds that should be logged. Instead, I get nothing to stderr, stdout, and nothing more to my log file. And my process just seems to hang there doing nothing.

I wonder if maybe the way I'm launching svn is wrong. Useful posts on the matter seem few and far between, but I did find one that suggested that the application being written to was terminating itself before the write could happen... Maybe something about the way I'm starting svn tells it to terminate if it starts to wait...

Does anybody have experience with this in .NET?

I agree, that is an excellent solution, but unfortunately I hit another snag there. I don't know why, but my Subversion hook (which is executing my program, which then executes svn) is being executed as a "phantom" user (and I just made that up so it has no specific meaning). The USERNAME environment variable is apparently an empty string. I haven't figured that out yet, since every workstation I've tested (as opposed to the development server) has an actual user executing it... So it's not going to be quite so easy, but I would certainly like to figure out why the USERNAME variable is empty... Does anybody know where the Subversion hook scripts get their user credentials from?

That sounds like a nice solution, but unfortunately the APPDATA environment variable is also empty when the hook script is executed. So I don't think Subversion is creating any kind of user data...

We're running VisualSVN Server, which AFAIK is using Apache. Personally, I wanted to just install Subversion and Apache myself...

I was looking at that, but I wasn't sure the --config-dir is the %APPDATA%\Subversion equivalent... I tried searching for confirmation, but couldn't find it... In hindsight I suppose it should be obvious, but testing is difficult and abstract through a hook script... Plus I've been pretty tired these past few days.

I can't say... I'm no longer at work and I'm honestly too tired to test it right now...

Heh, I'm now at work... Now I need to figure out how to go about testing this...

** EDIT **

It's taking longer than expected. Was having problems getting the service process to run as a custom user with restricted access and ownership of the desired directories. Hopefully I can confirm whether this --config-dir option solves my problem in the next hour.

I'm still curious why writing to stdin didn't work though... It was a poor solution to this problem, but it would be nice to understand how it works to write to stdin of another process like that for future reference.

** EDIT **

It just occurred to me to just try svn log on my local machine with a new --config-dir option specified to see if it would create the directory and prompt me again for authentication and the SSL certificate. It did so I'm pretty confident that this solution will work... At least, if nothing else goes wrong.

I'm unsure if the config directory is working or not... svn appears to be still prompting for confirmation, which doesn't seem to make sense because if a human user executes an svn command while pointing to the created Subversion client config directory they are not prompted to accept the certificate...

Well I wasn't actually writing the password to svn's stdin. Instead, I was writing a 't' character to temporarily accept the SSL certificate, which I just confirmed works from the command line in Windows by piping it.

svn log url
<svn prompt for confirmation>t
<output>
svn log url
<svn prompt for confirmation>t
<output>
echo t | svn log url
<output>

What exactly is the difference between reading from the owner terminal and stdin? I think that I was under the impression that the owner terminal would be writing to stdin, though I admit that my understanding of terminals is abstract and incomplete...

It seems to be working (at least in part) to specify the --config-dir option, but now I'm getting the following output to svn's stderr stream (by memory):

Authentication realm: (url) authentication_realm_name

It doesn't really resemble a prompt, but there is no further output and the program seems to hang there... When a colleague with server access executes the command from the Command Prompt it executes successfully and the above message isn't displayed (unless stderr isn't display by default in Windows, in which case I don't know if this message is written to stderr for the colleague). If it's not a prompt, then my only explanation is that it's actually just Apache being informative and my debugging code is blocking...

// Debugging code to try to see why/if svn is failing.

string line;

Program.StartLog("svn stderr:\n\n");
while((line = svn.StandardError.ReadLine()) != null)
  Program.Log(String.Format("{0}\n", line));

Program.StartLog("svn stdout:\n\n");
while((line = svn.StandardOutput.ReadLine()) != null)
  Program.Log(String.Format("{0}\n", line));

Does anybody know if this is the right/wrong way to read from the streams in C#? I've noted in examples that it seems the Flush() or Close() method needs to be called for some reason, but I don't really understand how you would go about reading again (as some programs would dictate) if the stream is closed... I don't really understand how to check if there is data to be read from a particular StreamReader; if so read it line by line and process it; and if not continue on with the program...

** EDIT **

I removed the above code from the program (I think) and it's still blocking on the svn process... I can't imagine any reason for svn to take more than a second to execute (it's only processing one file) unless it's prompting...

I'm not sure how I would do that in C#...

I originally wanted to use that option, but before I understood the --config-dir option I was trying to figure out how to respond to a prompt... I guess now I can go back to --non-interactive mode and hope that svn either succeeds or writes something useful to stderr.

Are you talking about svn's output when executed by my program or by my colleague from the command line? My colleague copied the output from svn to me and it was the standard successful output...

prompt>svn export arguments flags file Export complete.

From my program, svn is started with System.Diagnostics.Process.Start(ProcessStartInfo). The ProcessStartInfo instance has a FileName property (i.e. the executable) and an Arguments property. I'm not sure if it would work to add redirection arguments (especially with the UseShellExecute property set to false)...

I did try reading from the svn output streams and writing them to files:

Which seems to work on my local system, but is apparently never reached on the server... If there was an uncaught exception (while being executed by a user with no logon) what should happen to my program...? Would Windows terminate it or would it just stop executing and hang?

That's brilliant! I can't believe I didn't think of running svn from the batch file...

I'm not sure... Not that I can find... You did suggest that I call a more powerful script from my batch file, but instead I've opted to write a simple C# program to handle it. That's all I can find...

By executing svn from the batch file, the following was output to stderr:

svn: PROPFIND request failed on 'file' svn: PROPFIND of 'file': authorization failed (url)

stdout was empty.

You used --config-dir and --non-interactive? You should run it manually and add in the user and password information, since it seems it couldn't ask you for them.