C++ – Getting File Associations using Windows API

cfile-associationfile-typeregistrywindows

I'm working on a console based file browser for Windows in C++ and am having difficulties getting together a context menu that lists actions associated with a file and calls commands on them. The biggest issue right now is getting the actions tied to the file types.

I know of the process to open and tweak the registry keys in HKEY_CLASSES_ROOT but I can't find a way to actually get the actions and their commands so I can build a context menu out of it.

The general structure of these associations in the registry is:

HKEY_CLASSES_ROOT\(extension)\(default) – filetype
HKEY_CLASSES_ROOT\filetype\(default) – description of the filetype
HKEY_CLASSES_ROOT\filetype\shell\action\(default) – description of the action
HKEY_CLASSES_ROOT\filetype\shell\action\command\(default) – command called on file

I'm wondering if there is a way (hopefully using the Windows API) that I can get all of the actions associated with a file type. At least then I can check those actions for their commands in the registry…

Also, this approach doesn't seem to work with some common file types (e.g. mp3) on my system as the default key is left blank and another key ("PercievedType") is set to audio… How can I get the actions for something like this?

Lastly, if there is a better way to do this in general I would love to hear it, I generally hate dealing with the registry. I would much rather have a simple windows call that would get me the actions and commands…

Best Answer

Try this (error handling omitted for brevity):

TCHAR szBuf[1000];
DWORD cbBufSize = sizeof(szBuf);
HRESULT hr = AssocQueryString(0, ASSOCSTR_FRIENDLYAPPNAME,
   argv[1], NULL, szBuf, &cbBufSize);
if (FAILED(hr)) { /* handle error */ }
CStringA strFriendlyProgramName(szBuf, cbBufSize);

cbBufSize = sizeof(szBuf);
hr = AssocQueryString(0, ASSOCSTR_EXECUTABLE, 
   argv[1], NULL, szBuf, &cbBufSize);
if (FAILED(hr)) { /* handle error */ }
CStringA strExe(szBuf, cbBufSize);

std::cout << strFriendlyProgramName << " (" << strExe << ")" << std::endl;

Related Solutions

Windows – How to set up an editor to work with Git on Windows

Update September 2015 (6 years later)

The last release of git-for-Windows (2.5.3) now includes:

By configuring git config core.editor notepad, users can now use notepad.exe as their default editor.
Configuring git config format.commitMessageColumns 72 will be picked up by the notepad wrapper and line-wrap the commit message after the user edits it.

See commit 69b301b by Johannes Schindelin (dscho).

And Git 2.16 (Q1 2018) will show a message to tell the user that it is waiting for the user to finish editing when spawning an editor, in case the editor opens to a hidden window or somewhere obscure and the user gets lost.

See commit abfb04d (07 Dec 2017), and commit a64f213 (29 Nov 2017) by Lars Schneider (larsxschneider).
Helped-by: Junio C Hamano (gitster).
^{(Merged by Junio C Hamano -- gitster -- in commit 0c69a13, 19 Dec 2017)}

launch_editor(): indicate that Git waits for user input

When a graphical GIT_EDITOR is spawned by a Git command that opens and waits for user input (e.g. "git rebase -i"), then the editor window might be obscured by other windows.
The user might be left staring at the original Git terminal window without even realizing that s/he needs to interact with another window before Git can proceed. To this user Git appears hanging.

Print a message that Git is waiting for editor input in the original terminal and get rid of it when the editor returns, if the terminal supports erasing the last line

Original answer

I just tested it with git version 1.6.2.msysgit.0.186.gf7512 and Notepad++5.3.1

I prefer to not have to set an EDITOR variable, so I tried:

git config --global core.editor "\"c:\Program Files\Notepad++\notepad++.exe\""
# or
git config --global core.editor "\"c:\Program Files\Notepad++\notepad++.exe\" %*"

That always gives:

C:\prog\git>git config --global --edit
"c:\Program Files\Notepad++\notepad++.exe" %*: c:\Program Files\Notepad++\notepad++.exe: command not found
error: There was a problem with the editor '"c:\Program Files\Notepad++\notepad++.exe" %*'.

If I define a npp.bat including:

"c:\Program Files\Notepad++\notepad++.exe" %*

and I type:

C:\prog\git>git config --global core.editor C:\prog\git\npp.bat

It just works from the DOS session, but not from the git shell.
(not that with the core.editor configuration mechanism, a script with "start /WAIT..." in it would not work, but only open a new DOS window)

Bennett's answer mentions the possibility to avoid adding a script, but to reference directly the program itself between simple quotes. Note the direction of the slashes! Use / NOT \ to separate folders in the path name!

git config --global core.editor \
"'C:/Program Files/Notepad++/notepad++.exe' -multiInst -notabbar -nosession -noPlugin"

Or if you are in a 64 bit system:

git config --global core.editor \
"'C:/Program Files (x86)/Notepad++/notepad++.exe' -multiInst -notabbar -nosession -noPlugin"

But I prefer using a script (see below): that way I can play with different paths or different options without having to register again a git config.

The actual solution (with a script) was to realize that:
what you refer to in the config file is actually a shell (/bin/sh) script, not a DOS script.

So what does work is:

C:\prog\git>git config --global core.editor C:/prog/git/npp.bat

with C:/prog/git/npp.bat:

#!/bin/sh
"c:/Program Files/Notepad++/notepad++.exe" -multiInst "$*"

#!/bin/sh
"c:/Program Files/Notepad++/notepad++.exe" -multiInst -notabbar -nosession -noPlugin "$*"

With that setting, I can do 'git config --global --edit' from DOS or Git Shell, or I can do 'git rebase -i ...' from DOS or Git Shell.
Bot commands will trigger a new instance of notepad++ (hence the -multiInst' option), and wait for that instance to be closed before going on.

Note that I use only '/', not \'. And I installed msysgit using option 2. (Add the git\bin directory to the PATH environment variable, but without overriding some built-in windows tools)

The fact that the notepad++ wrapper is called .bat is not important.
It would be better to name it 'npp.sh' and to put it in the [git]\cmd directory though (or in any directory referenced by your PATH environment variable).

Ios – How to develop for iPhone using a Windows development machine

It's certainly possible to develop on a Windows machine, in fact, my first application was exclusively developed on the old Dell Precision I had at the time :)

There are three routes;

Install OSx86 (aka iATKOS / Kalyway) on a second partition/disk and dual boot.
Run Mac OS X Server under VMWare (Mac OS X 10.7 (Lion) onwards, read the update below).
Use Delphi XE4 and the macincloud service. This is a commercial toolset, but the component and lib support is growing.

The first route requires modifying (or using a pre-modified) image of Leopard that can be installed on a regular PC. This is not as hard as you would think, although your success/effort ratio will depend upon how closely the hardware in your PC matches that in Mac hardware - e.g. if you're running a Core 2 Duo on an Intel Motherboard, with an NVidia graphics card you are laughing. If you're running an AMD machine or something without SSE3 it gets a little more involved.

If you purchase (or already own) a version of Leopard then this is a gray area since the Leopard EULA states you may only run it on an "Apple Labeled" machine. As many point out if you stick an Apple sticker on your PC you're probably covered.

The second option is more costly. The EULA for the workstation version of Leopard prevents it from being run under emulation and as a result, there's no support in VMWare for this. Leopard server, however, CAN be run under emulation and can be used for desktop purposes. Leopard server and VMWare are expensive, however.

If you're interested in option 1) I would suggest starting at Insanelymac and reading the OSx86 sections.

I do think you should consider whether the time you will invest is going to be worth the money you will save though. It was for me because I enjoy tinkering with this type of stuff and I started during the early iPhone betas, months before their App Store became available.

Alternatively, you could pick up a low-spec Mac Mini from eBay. You don't need much horsepower to run the SDK and you can always sell it on later if you decide to stop development or buy a better Mac.

Update: You cannot create a Mac OS X Client virtual machine for OS X 10.6 and earlier. Apple does not allow these Client OSes to be virtualized. With Mac OS X 10.7 (Lion) onwards, Apple has changed its licensing agreement in regards to virtualization. Source: VMWare KnowledgeBase

Best Answer

Related Solutions

Windows – How to set up an editor to work with Git on Windows

launch_editor(): indicate that Git waits for user input

Ios – How to develop for iPhone using a Windows development machine

Related Topic

`launch_editor()`: indicate that Git waits for user input