One of the requirements for this project is that it must be able to launch w/out admin. It is a massive project, so I can't really show you the source and a meaningful and helpful way
I've gone to some people for help, and they suggest that I look throughout my project for any times I write files. However, I can't think of anywhere else I still do this, and yet the exe will only run in admin mode. If you try and run it in non-admin mode, it crashes.
I understand that it's difficult to debug if you can't see project, but the project is hundreds of files. Mainly, I'm looking for advice on the kinds of things that would cause a program to crash in not admin mode but run perfectly fine in admin mode
Just as the many people suggested, the issue was opening a file with read/write privileges. Even though we were only reading from the file, we opened the file as an fstream instead of an ifstream.
I missed it because the problem was hiding in some string utils functions that were written by another team member who is no longer with the team. Pretty much no one was using those string functions or was aware they existed.
Thanks for yours guys' suggestions regardless!
For starters, I don't think you can run and install vcredist_x86.exe without admin privileges.
Other than that, in general to not ask for UAC, I think you need to setup the PrivilegesRequired properly.
EDIT: To work-around the need to install vcredist you could use static runtime linking. However, that has some disadvantages as well (for example, memory allocation/deallocation must then be always done in the same memory context, i.e. the same dll/executable - which is always the best policy anyway).
Related
I'm creating a C++ linux application that needs some initial parameters of configuration to work correctly, these externals configurations is needed to avoid multiple compilations for parameters changes, and this configurations needs to be unknow by the end users. I was thinking an way do make an hidden configuration file that is consumed at the first execution, and always is researched at execution to verify possibles changes. Some suggestion to do this?
It is unlikely that you can hide the configuration file so that people do not know its existence: most Linux users would want to know which files you are installing in which location, and there are many ways to help them in discovering that, even if you try to do it without telling them (the simplest way that comes to my mind, they may do a file system snapshot and compare it before and after running the install program)
If your goal is to prevent people from changing the configuration without your permission (i.e., without paying for a license upgrade), you may do it by requiring the configuration to be signed from your company, storing the verification key inside the executable.
If you want to prevent the configuration from being read you don't have that much luck: there is not much that can stop a motivated attacker from reading the content of that file, since your application must be able to do it as well.
I recently downloaded the "CppCode" app for my iPhone and I was just wondering if it was at all possible to access files, change settings, delete things, make calls, etc.
Let's say I wanted to send a text to a friend - could this be possible within the C++ compiler on the iPhone?
This isn't really a question for stackoverflow, but the answer is no. Your phone, by default, protects its files from apps. Each app exists in its own "sandbox", and is not allowed to leave it under any circumstances. This is what jailbreaking does, it gives you root access to the rest of your phone's internal directories. Even then, I don't think it would be possible. If you really want to do stuff with that, you're better off making an app. I wouldn't try to program stuff from inside some compiler program on-board the phone..
I've been looking into using Mercurial for version management and wanted to try it out. I'm planning on doing a project on my own to help me learn C++ coming from Java and thought it would be a good idea to try version management with it. It would probably be a game or some sort of simple application, not sure with a GUI or not.
The problem is I don't know much about version management. When in a project is a good time to make the repository? Should I just do it right away? How often should I make commits?
I'll be using Netbeans for my development since it seems to be pretty good, also has Mercurial controls built in, but what should I set in the .hgignore for my project? I assume the repository would be the whole folder Netbeans creates but what should I make it ignore?
Bonus questions: I'll be using Bitbucket for hosting/backup, should I make the project public? Why/why not? Also would that make it open source? Should I bother with attaching a license? Because I have no idea how the licenses work and such. Then again, I sincerely doubt I'll be making anything anyone will want to copy too badly.
On repos:
You should use a VCS repository as soon as possible. Not only does it allow for off-site backups, but it allows you to track changes. To find out when a bug was introduced.
Having a VCS, particularly a distributed VCS like Mercurial, will change the way you code. You won't have to be careful not to break things, because you always have the old version that you can revert to. If, after a few weeks or months, you decide that a particular course of development was a bad idea, you can rewind all the way back to some prior point.
You should generally commit either every day, or every time you finish a task. Like, you might have a 4-hour task of "write this class and get it working". You commit after that. When you're done for the day, you commit. I wouldn't suggest committing in a non-compiling state, though, so you should try to stop for the day only when everything still builds.
As for ignoring, you should ignore things you don't intend to commit. Things that you wouldn't want in the repo. Generated files, temporary files, the stuff that you wouldn't need.
What should be in the repo is 100% of the information necessary to build the project from scratch (minus external dependencies).
On licenses:
I would say that it is very rude to put up a public repository without some kind of license attached. Without a license, that means that anyone even pulling from the repo (which is what you're inviting by making it public) is a violation of your copyright without direct, explicit permission from you.
So either look at how copyright works and pick a license to release your stuff under, or keep your repos private.
The instant you conceive of it, usually. There is no penalty for putting everything you have into a VCS right away, and who knows, you may want that super-duper prototype version later on down the road. Unless you're going to be checking in large media files (don't), my answer is: right now.
As for how often to commit, that's a personal preference. I use git, and as far as I'm concerned there is no problem with checking in every time you make some unit of significant change. The more snapshots along the way you have, the easier it becomes to track down bugs later on.
Your .hgignore is up to you. You need to decide what to version and what not to. As a rule of thumb, any files generated during compilation probably shouldn't be checked in.
Also, if you release it to the public, please attach a license. It doesn't matter what it is, but it makes all the bosses and lawyers in the world happy when they know what they can and can't do with your code. Finally, please don't release something to the public unless you think someone else will benefit from it. The internet already suffers from information overload.
Commit early, and commit often.
With distributed VCS like hg or git there's really no reason not to start a repo before you even write any code. If you decide to scrap your project, you can always delete your repo before you post it to whatever hosting site you're using. The more often you commit, the easier it will be to hone in on where you messed up later on (you will).
Stuff to put in your ignore file would be build files and anything that your IDE generates periodically, like user preferences and tag caches. You don't want to foist your preferences on someone else and you don't want to have to create a commit every time you change the position of a window in the IDE. What's in the repo should be the minimum that someone would need to be able to work on your project.
If you're just doing a small project to learn, then I wouldn't worry about licenses or having a private repo. You can always add a license later. Alternatively, just pick a permissive license and go with it.
Based on my experience with git, I would recommend the following:
Create repository along with project.
Commit as often as you can with detailed comments
When you want to test a new idea - create a branch. If the idea is successful, merge your code to the master branch. If the idea is not successful, you can just discard the branch. Probably this is the most important idea.
Put the names of object files, executables and editor backup files in the ignore list.
Disclaimer: I'm not a c++ developer, I can only do basic things. (I understand pointers, just my knowledge is so rusty, I haven't touch c/c++ for about 20 years :) )
The setup: I have an Outlook addin, written in C#/.Net 1.1. It uses a c++ shim to load.
Usually, this works pretty well, and I use in my c# code nlog for logging purposes. But sometimes, the addin fails to load, i.t. it does not hit the managed code at all for me to be able to investigate the problem from the log files.
So, I need to hook some basic logging into the c++ shim - just writing in a file. I need to make it as simple as possible for our users to enable. Actually I would prefer not to ship it by default.
I was thinking about something, which will check if a specific dll is present (the logging dll), and if so, to use it. Otherwise, it will just not log anything. That way, when I have a user with such a problems, I can send him only the logging dll, the user will save it in the runtime directory, and I'll have the file.
I guess this have to be done with some form a factory solution, which returns either a dummy logger, or if the dll is found, a real one.
Another option would be to make some simple logger, and rebuild the shim with or w/o using it, based on directives. This is not the desirable approach, because the shim needs to be signed, and I have to instruct the user to make a backup copy of the "real" one, then restore when done, etc., instead of just saving and deleting a dll.
I'd appreciate any good suggestion how to approach it, together with links or sample code how to go after this.
Cheers
The loading of the logging dll's seams like a complicated way of handling the configuration issue. Why not use the registry. If you use conditional loading on dlls you will be using LoadLibrary and GetProceAddress and as you said your not really a c++ coder so why introduce the complexity. Also there have to be n+1 c++ logging libraries available have you looked into any of those.
Some I found after a Google search
log4cpp
rlog
Why not have a registry key for that? The user opens regedit, adds a key and your library starts logging. The logging code will be in place all the time, just not invoked when the key is absent or set to "no logging".
Our win32 applications (written in C++) have been around for over 10 years, and haven't been updated to follow "good practices" in terms of where they keep files. The application defaults to installing in the "C:\AppName" folder, and keeps application-generated files, configuration files, downloaded files, and saved user documents in subfolders of that folder.
Presumably, it's "best practices" to default to installing under "c:\Program Files\AppName" nowadays. But if we do that, where should we keep the rest of our files? Starting from Vista, writing to the program files folder is problematic, and there seem to be a million other places that you can put different files, and I'm confused.
Is there a reference somewhere for what goes where?
Edit: To expand on questions people have asked so far:
I'm familiar with the SHGetFolderPath function, but there are lots and lots of options that you can get from it, and I can't find a resource that says "Here is exactly what each of these options is used for, and when you might want to use it".
Up until now, we've done the "All files, including saved user files, under one folder" thing, and it's worked fine - but not when people want to install the app under the Program Files folder. For some reason, the virtualization monkeying around that Vista does isn't working for our application; if we're going to be making changes anyway, we might as well make an effort to do things the "right" way, since we don't want to have to change it again in 12 months time.
Further question:
We include some "sample" documents with our app, which we update every now and again. Is it appropriate to install them into My Documents, if we'll be overwriting them every few months? Or is My Documents assumed to be totally safe for users to mess around in?
If we can't install them to My Documents, where should we put them so that users can see them easily?
Presumably, it's "best practices" to default to installing under "c:\Program Files\AppName"
Close, but not quite. Users can configure the name of the Program Files folder and may not even have a C: drive. Instead, install to the %ProgramFiles%\AppName environment variable folder.
Note you should assume you only have read access to this folder after the installation has finished. For program data files where you might need write access, use %AppData%\AppName.
Finally, are you sure yours is the only app with that name? If you're not 100% certain of that, you might want to include your company name in there as well.
The mechanisms you use to retrieve those variables will vary depending on your programming platform. It normally comes down to the SHGetFolderPath() Win32 method in the end, but different platforms like Java or .Net may provide simpler abstractions as well.
Some guidelines are in this Knowledge Base article: How to write a Windows XP Application that stores user and application data in the correct location by using Visual C++. Also, if you search MSDN for Windows Logo Program you will find documentation regarding what an app needs to do to be truly compliant.
SHGetKnownFolderPath can get you the directories you need. If backwards compatibility with XP and earlier is required, use the deprecated SHGetFolderPath
Having said that, if you app came with documentation that said "everything used by this app is in this directory" I would love it ;)
Use the Windows SHGetFolderPath() function to get the correct directories.
Edit: To reply to your other question, added in the edit: Where to put the sample files of your application does very much depend on whether your application is installed for a single user or for all users, and whether the person installing the application can be assumed to be the one who uses it.
If your program is to be used by multiple users on a system, copying stuff into "My Documents" is not going to work - the files would be accessible only for the user installing the application. Worse, if the only user of your application needed to install as Administrator, then [s]he will not have access to the files either. So unless you are fairly certain that there is only one user for your application, and they have sufficient permissions to install the application using their own account, don't use "My Documents".
IMO you should install sample files into the directory identified by CSIDL_COMMON_APPDATA. This will give you exactly one copy for all users, and since you want every user to see the original, unaltered sample files all users should consider them read-only. In fact, your setup program should probably make them read-only. Opening one of the samples will work for all users, but as soon as they try to save their modifications the application should detect that the file is read-only, and open the "Save As" dialog, pointing to "My Documents" or suitable directory inside. That will also keep all user modifications when the installer updates the sample files later on.
It is of course somewhat more difficult for the users to find the sample files. You could add a link to the samples folder to the start menu group of your application, so that access to the files is fast, and of course you should properly document everything.
For your application binaries, you can assume that you may write to the PROGRAM FILES directory (use the %ProgramFiles% environment variable to support installations other than the default English version - e.g. in german Installations this will be c:\Programme by default). Wikipedia lists the most common variables. Another option are the SHGetFolderPath or newer SHGetKnownFolderPath functions.
For User data, you should assume that the application is running with limited access rights and may only write to the user's home directory. Same applies for registry entries. This path should probably be configurable b the user, as the home directory may actually be a network server and a user might have a second disk attached for data storage. For information on the current (Vista) filesystem guidelines see this article.
Regarding plugins, this might be more complicated. The best practice seams to be offering the option to install for the current user only, and placing the plugin in the user directory, or install for all users and place the files into your program files directory (but remember to check for write permission and request elavated access if needed).
There are plenty of environment variables like: %USERPROFILE%, %HOMEPATH%, %APPDATA% all of these points to some user-specific directories, where you can put your user-specific files.
For system-wide storage you can use %ALLUSERSPROFILE%, that is the place where you should put your read/write datafiles that are not specific to any user.
Sorry I don't know the correct answer, but...
Do you have a business case for wanting to do that? Are your customers complaining that files aren't stored where they expect? Are your applications crippled in some way because you store files in non-standard locations? If not, I don't see a reason for spending time and budget to redo your file storage strategy just to meet "best" practice. If your programs just work, then IMHO you should leave them alone and spend money and time on things that matter.
There is a directory structure under c:\users for user oriented data.
There is documentation for porting apps from older windows OSs to Vista.
Check out http://www.innovateon.com and follow the links to Vista. There is documentation regarding certification that has the details on topics like this.
We have a similar app created ~10 years ago using MFC. The easiest thing to do was create a folder right off of C:\ (e.g. C:\OurApp). No install files, no special permissions, no registry changes, etc. Clients (and particularly their sys admins) LOVE it.
One other consideration - are you planning to all of a sudden change the installation folder for existing clients (assuming this is installed in many locations)? If something isn't broke, why fix it?