I used rebar to create a release for my Erlang application.
My application need to read data from a file. Normally, it is located in the directory where I start erl.
But when it comes to release, I don't know where can I put the data so as the application can access it. I tried to put the file in both rel/myrelease/bin and rel/myrelease/release/myverison but the log always show:
{{badmatch,{error,enoent}},
As explained in the application design principles documentation, normally you put application data into the application's priv directory, and your application code uses the code:priv_dir/1 function to locate its priv directory at runtime in order to find its data files.
Related
I'm writing a console app for windows that sets up an environment and launches (popen) various hpc-apps using msmpi mpiexec.exe.
I have an msmpi installation installed locally to the application I'm writing. All works fine and parallel processing is OK.
However, as soon as I happen to have a system installation of msmpi as well (as installed by e.g. msmpisetup.exe), my applications stubbornly loads the Windows/system32/msmpi.dll instead of the msmpi.dll that I point at using PATH. Since the system msmpi.dll is of a different version, my apps does not run.
The PATH env.var. is set within my app, and it is apparently inherited correctly by the child processes, including mpiexec.
The only remedy I've found is to either (1) Rename system32/msmpi.dll or (2) place a copy of "my" msmpi.dll into every folder in which I have a parallel executable. Both remedies are... not nice.
How can I prevent my apps from selecting the system32/msmpi.dll and use the instance that's in the PATH instead??
Thank you for any advice.
N
The standard DLL search order in Windows is documented to be
The directory from which the application loaded.
The system directory. Use the GetSystemDirectory function to get the path of this directory.
The 16-bit system directory. There is no function that obtains the path of this directory, but it is searched.
The Windows directory. Use the GetWindowsDirectory function to get the path of this directory.
The current directory.
The directories that are listed in the PATH environment variable. Note that this does not include the per-application path specified by the App Paths registry key. The App Paths key is not used when computing the DLL search path.
If you want your application to check a specific location first before using the system locations, you can call SetDllDirectory in the parent application before letting it execute other binaries that require a particular DLL.
I'm trying to set CommType in connection string for Advantage DataBase Server using Entity Framework 5 and Advantage Data Provider in a .NET Web Application.
Connection string is in properties.config file.
I trie to use ads.ini but I don't know where to put it (I try in wwwroot/site/bin but nothing happened)
I need to set this parameters:
RETRY_ADS_CONNECTS = 5
PACKET_SIZE=512
USE_TCP_IP = 1
I can do this whiteout errors, but not using properties.config file.
AdsConnection conn = new AdsConnection("data source=\\\\SERVER1\\DATA; ServerType=remote;TableType=CDX;CommType = TCP_IP");
Any clue about how to solve this? Using ADS.INI or properties.config file, same for me.
Thank you!
Gaston Brave.
You can use the ADS.INI file for this purpose. Where it needs to be located (or how to tell Advantage where to find it) depends on the OS you're using.
From the Advantage Help file topic ADS.INI:
Windows
In order for the ads.ini file to be used, it must be located in the application directory, the Windows directory, the Windows System directory, or the client's search path.
In addition, if an environment variable exists with the name adsini_path, that path will be used to locate the ads.ini file. This can be helpful when you do not want to modify the application’s search path, but still need the ads.ini file to exist in a directory multiple users have rights to (for example on Windows Vista installations). An application can often set the environment variable at run-time before calling any Advantage functions, which avoids the need to set a per-workstation environment variable.
Linux
In order for the ads.ini file to be used, it must be located in the application directory, a directory specified in an environment variable named ADSPATH, in the users home directory, or in the /etc directory. If located in the users home directory the ads.ini file should be named .ads.ini (note the initial "dot").
How to correctly use JSON settings files in windows services build in 3.1 net core, that are published in a single file.
Publishing as single file, requires you to do two things. First, exclude the settings JSON file from the single file. If you do not do it, it will be unpacked together with the rest, loaded and it will appear to work, if there are default values in it. And second, copy the settings file to the publish directory. You can do this by adding this:
<ItemGroup>
<Content Update="appsettings.json">
<CopyToPublishDirectory>Always</CopyToPublishDirectory>
<ExcludeFromSingleFile>true</ExcludeFromSingleFile>
</Content>
</ItemGroup>
In your pubxml profile. Building it from the interface with: Build > Publish (Project name) will not work. You gotta use the command line from now on.
Once packed into a single file, the base path of your application is changed. Simply placing the JSON files next to your exe will not do the trick. Also, you will be using windows services. Starting the exe is one thing, starting the service is another universe. In most situations you can use the following:
Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName);
To get the directory of your single-file packed exe service.
The packed exe checks the temp folder it creates for resources, you need to redirect some of the features to another folder. You will want to do this, at least for your log files and settings. For example, if you want the application to check for JSON files near your exe, you add this:
.ConfigureAppConfiguration((context, config) =>
{
config.SetBasePath(Path.GetDirectoryName(Process.GetCurrentProcess().MainModule.FileName));
})
in your CreateHostBuilder method.
I hope that this will save you some time. Ive been fighting this all morning.
I have .Net desktop app which users can download from my website. I want to customize this app to per user basis.
Is there way to modify exe before downloading, just to change few strings with appropriate for the users downloading ?
Or it is possible to pass command line parameters to this exe via URL ?
The .exe file needs to be customized for it to behave differently for certain downloads.
Skip below to find the solution I found tolerable.
Add section to the .EXE file – Not ideal.
The .exe file has sections one after the other. You could add a section with your data in it, which the executable would then read. This requires you to modify (have access to) the source code of the executable for it to do anything meaningful with the data. Also getting familiar with the .exe file format and modifying it on the web server side as well al playing with it in the program's source code is somewhat tedious.
Change resources section of the .EXE file – Not ideal.
A dedicated "resources" section exists in the executable. You could add custom strings or blob of data to it. Same cons as the first one.
Overwrite data in the .EXE at a fixed position – Passable.
Have the executable read data from itself from a fixed position in the file, which is overwritten with the customization data when serving the .exe file. Requires modifying the executable's source code.
Append data to the .EXE – Passable.
Append data to the executable. Again, reading it and doing anything special with it requires the executable itself doing so.
☑ Wrap the .EXE in another .EXE and append your data to it – Tolerable.
Create a program to which the original executable and the custom data will be appended to. When this custom program is then executed, it will extract the embedded executable and launch it with the custom data as it arguments.
This kind of a bundle-executable is also easy to produce on most server-side (scripting) languages. When the download is requested, the server sends the wrapper-exe, the original exe, the customized data and of course some statically-sized data fields denoting the sizes of both of those data blocks so it can extract them.
Cons: Requires such a wrapper program to be created, unless someone already has.
Related links:
1. Best practices to let my web users download custom .exe from my site using PHP
2. Modifying executable upon download (Like Ninite)
If the application is ClickOnce deployed, passing URL parameters is an option in the ClickOnce options dialog. However, I have not yet used this feature.
EDIT
You might want to change some user settings in your configuration depending on the user that actually runs the application. You could also make sure this is done only once per user by adding an appropriate SettingsNeedUpdate setting you set to true after the initial initialization.
Example:
Add new setting "Option1", "Option2" and "SettingsNeedUpdate" which are user settings. In Main you could add something like:
...
try
{
if (Properties.Settings.Default.SettingsNeedUpdate)
{
Properties.Settings.Default.Option1 = ...;
Properties.Settings.Default.Option2 = ...;
Properties.Settings.Default.SettingsNeedUpdate = false;
Properties.Settings.Default.Save();
}
}
catch (Exception exp)
{
...
}
...
You could write a library which can modify an assembly resources (here string table).
This library could benefit from reflection.
When a user asks for your file, asp.net page could customize the exe (using your library) and send it to client.
Not like that, No.
You could however automatically zip (on your server) your exe with a custom app.config file for each user.
Update
Point your download location to a custom HttpHandler that zips together your exe (using http://www.sharpdevelop.net/OpenSource/SharpZipLib/) with a generated (for the current user) application configuration file ( http://generally.wordpress.com/2007/09/27/using-appconfig-for-user-defined-runtime-parameters/).
The user then unzips the two files (MyApp.exe & MyApp.exe.config) to any location and run MyApp.exe.
This method does not work if you have an installer.
Is there a standard place to put the mnesia database within erlang? At the moment I am putting it in the priv directory.
By default, Mnesia will create the schema in a subdirectory called Mnesia.<node name> of the current directory of the emulator process.
If that's not what you want, all you need to do is set Mnesia's dir application variable with something like
application:set_env(mnesia, dir, "/path/to/db").
As for where to place the database: that depends on your deployment scenario. Since application
variables can also be set using release config files or command line arguments, you can delay that
decision until you ship (or install on your own servers). For use in production, a standard directory like /var/lib/<your application>/mnesia-<node name>(on unix) should do.
For playing around, i'd recommend using a dedicated directory under the code root (NOT the priv directory) and setting that location within your application's startup section.
In my pet projects, i often use code such as
Root = filename:absname_join(filename:dirname(?FILE), ".."),
application:set_env(mnesia, dir, filename:join(Root, "db")).
for exactly that purpose.
As far as I know, when you create the schema every node creates a schema directory in its root directory.
Therefore, I guess that can be considered the default location.
If, for some reason, you have to include a schema together with your application, well, I guess the priv folder should be fine, since it is supposed to be used for application specific files and it's easily accessible via the code:priv_dir/1 function.