Launching a program

[c-unit]

What is the best way to navigate to a certain folder, then launch a program? Other than using System()? in C++.

[i300]

Did you try google searching this?

[editline]11:45PM[/editline]

There are lots of answers on google. Lots of them. Facepunch won't google for you.

[turb_]

[QUOTE=c-unit;23196877]What is the best way to navigate to a certain folder, then launch a program? Other than using System()? in C++.[/QUOTE]

Let me guess, people said system() is bad, so you want to use something else which does the exact same thing.

[Chryseus]

[url]http://msdn.microsoft.com/en-us/library/ms682425%28v=VS.85%29.aspx[/url]
There

[esalaka]

The only cross-platform solution is system, and even that isn't really cross-platform. :P

[Spoco]

[URL=http://msdn.microsoft.com/en-us/library/bb762153%28VS.85%29.aspx]ShellExecute[/URL] if you want to for example open a file in the program it's associated with or open web URLs in the default browser.

[jA_cOp]

Pretty sure boost has a portable interface for creating and managing child processes.

(And portable folder navigation)

[efeX]

[QUOTE=esalaka;23198683]The only cross-platform solution is system, and even that isn't really cross-platform. :P[/QUOTE]

shit I wish my program that launched another program was cross platform! Better not use system() !

[jA_cOp]

[QUOTE=efeX;23199238]shit I wish my program that launched another program was cross platform! Better not use system() ![/QUOTE]

Portable libraries are often much easier (and nicer) to use than native system interfaces anyway. Working with the WinAPI in C++ isn't exactly the most pleasant experience, even if you're very familiar with it. Same can be said for POSIX, if he's on Linux, Unix or Mac etc.

edit:

And the system function might not do what he wants, as it blocks.

[Spoco]

I'm sure using the WinAPI for a newbie is a much more pleasant experience than trying to figure out how to install/use third party libraries, and he's probably launching a Windows specific program anyway.

But using system() for this is just bad practice.

[jA_cOp]

[QUOTE=Spoco;23199430]I'm sure using the WinAPI for a newbie is a much more pleasant experience than trying to figure out how to install/use third party libraries, and he's probably launching a Windows specific program anyway.

But using system() for this is just bad practice.[/QUOTE]

I don't see how configuring a third-party library is any difficult at all. Boost even comes with an installer, and most boost modules are header-only (although the file-system stuff requires you to link against one library). And you still have to figure out how to use the WinAPI, which isn't any easier than learning boost-filesystem. If he just wants working code, there's lots of examples out there for either, but the WinAPI examples won't make any sense to a beginner, compared to the nice object-oriented interfaces boost provides.

[c-unit]

So for ShellExecute

ShellExecute(handle, "open", "C:\\Program Files\\Steam\\steamapps\\vypr11\\garrysmod\\hl2.exe, NULL, NULL, SW_SHOWNORMAL);

I just want my program to launch gmod, will the code above work?

[CammieDee666]

[QUOTE=c-unit;23208869]So for ShellExecute

will the code above work?[/QUOTE]

Test it and see

[c-unit]

Didn't work..it said handle is an unknown identifier

[cdlink14]

[QUOTE]ShellExecute(handle, "open", "steam://rungameid/4000", NULL, NULL, SW_SHOWNORMAL);[/QUOTE]

Should work...

[editline]08:57PM[/editline]

ShellExecute(handle, "open", "C:\\Program Files\\Steam\\steamapps\\vypr11\\garrysmod\\hl2.exe, NULL, NULL, SW_SHOWNORMAL);

The closing quote is missing on the filepath.
it should be:

ShellExecute(handle, "open", "C:\\Program Files\\Steam\\steamapps\\vypr11\\garrysmod\\hl2.exe[B]"[/B], NULL, NULL, SW_SHOWNORMAL);

[c-unit]

How can I find out what the game Id's are?

[cdlink14]

GMOD's ID is "4000"

try this:
[QUOTE]ShellExecute(handle, "open", "steam://rungameid/4000", NULL, NULL, SW_SHOWNORMAL);[/QUOTE]

[c-unit]

Also when using the fixed ShellExecute you gave me, I get this build error

steam game launcher.cpp(22): error C2065: 'handle' : undeclared identifier

[editline]02:00PM[/editline]

Ok I will try it thanks

[editline]02:01PM[/editline]

I still get that same build error using

ShellExecute(handle, "open", "steam://rungameid/4000", NULL, NULL, SW_SHOWNORMAL);

[ZeekyHBomb]

What does the error tell you >_>

[c-unit]

That I am forgetting to #include something, right?

[ZeekyHBomb]

No. It's telling you that on line 22 you're using something called 'handle', which it doesn't know about.
handle could in theory be defined in some header you can #include, but the msdn-page more or less can tell you that this is certainly not what's missing.

[c-unit]

Ah I was missing the Shellapi header

[Spoco]

[quote=MSDN]hwnd [in, optional]
HWND

A handle to the owner window used for displaying a UI or error messages. This value can be NULL if the operation is not associated with a window.[/quote]

Since you don't have a window, you use NULL.

[c-unit]

Still not working D:

[editline]02:21PM[/editline]

Oh I Will try that thanks

[editline]02:21PM[/editline]

Build Error:

steam game launcher.cpp(24): error C2664: 'ShellExecuteW' : cannot convert parameter 2 from 'const char [5]' to 'LPCWSTR'
1> Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast

[Spoco]

[URL]http://social.msdn.microsoft.com/forums/en-US/vclanguage/thread/c1b08c0a-a803-41c3-ac8c-84eba3be1ddb/[/URL]

Basically there are two versions of every WinAPI function that takes or returns strings. Wide/Unicode version (ShellExecuteW) and an ANSI version (ShellExecuteA), which one is used when you call ShellExecute depends on your IDE/compiler settings. Nowadays in Visual Studio, the wide versions are used by default.

You can either explicitly call ShellExecuteA, or prefix your literals with L ("open" becomes L"open").

[pikzen]

cannot convert parameter 2 from 'const char [5]' to 'LPCWSTR'

should be const char[8] no ?

[editline]10:30PM[/editline]

const char yourChar[8] { 'L', 'P', 'C', 'W', 'S', 'T', 'R' };

If not, excuse me, I'm not really fluent with C++.

[esalaka]

[QUOTE=pikzen;23214224]

cannot convert parameter 2 from 'const char [5]' to 'LPCWSTR'

should be const char[8] no ?

[editline]10:30PM[/editline]

const char yourChar[8] { 'L', 'P', 'C', 'W', 'S', 'T', 'R' };

If not, excuse me, I'm not really fluent with C++.[/QUOTE]

No. LPCWSTR is some weird Microsoft datatype. I think it means Long Pointer to C Wide STRing. Which means that you have enabled Unicode support and should convert your strings into wide characters first.

[pikzen]

Oh, thanks.
I guess I'll go to sleep smarter tonight :eng101:

[editline]11:11PM[/editline]

[url]http://www.cplusplus.com/forum/windows/2359/[/url]
?

[c-unit]

[QUOTE=esalaka;23215285]No. LPCWSTR is some weird Microsoft datatype. I think it means Long Pointer to C Wide STRing. Which means that you have enabled Unicode support and should convert your strings into wide characters first.[/QUOTE]

How do I go about doing so

[jA_cOp]

[QUOTE=c-unit;23215957]How do I go about doing so[/QUOTE]

Do what Spoco said, and prefix the string literal with L.

[cpp]
// ShellExecute defaults to ShellExecuteW on your system, so we need 16-bit character (wide) strings:
ShellExecute(NULL, L"open", L"steam://rungameid/4000", NULL, NULL, SW_SHOWNORMAL);

// or explicitly use ANSI ASCII version:
ShellExecuteA(NULL, "open", "steam://rungameid/4000", NULL, NULL, SW_SHOWNORMAL);
[/cpp]

I thought you wanted to actually search for a file in a directory structure, then execute it. For just launching a game, the WinAPI is fine.