On Windows 7, I can hit Start then type "run" and it will give me the windows classic run dialog, in which I can type various programs and commands.
If I wanted to perform a Run action using a C++ program, how would I go about doing that?
Ex: If I open the Run dialog and type "mspaint", it opens Paint. How could I use C++ to run "mspaint" and get the same results as the Run dialog itself?
std::system("program call"); is one way to go in case you don't need to interact with the process of the opened program.
system() returns the return value of the called program.
First, a handy shortcut: rather than having to type "run" into the start menu, you can use Windows+R (hold down the Windows key and press R).
Second, ShellExecute will work, but system on Windows does in fact work on non-program files, and it's certainly simpler to use than ShellExecute, unless you need something specific like running an application minimized.
The only caveat is that system() cannot be called by a Windows application. It can only be called from a console app.
Related
This is kind of an odd question but does anyone know how to make a c++ program open multiple separate CMD prompts? they don't even have to be proper command prompts they can spit out text in a separate CMD like window that's fine. they don't need to talk to each other or do anything more than display text. the only reason I'm not doing this in Batch is because it needs to be a compiled EXE. I know I can run windows commands in c++ with "system(...)" however I'm not sure how to force these to be separate windows. if anyone knows a way to do that I would greatly appreciate it.
Thank you for your time
You can use CreateProcess to rum cmd,and communicate through pipe.
Your question is not clear to me, but let me try:
A single process can have no or exactly one console window. E.g. in Visual Studio, in the linker settings, you can set the subsystem to console, then the console window is opened automatically or you can use AllocConsole to get one. If you need more windows to display text, you have to create these windows by yourself (these windows aren't normal console windows). Another possibility is to start more backgroud processes, each having its own console window to display the text. To start these background processes, use CreateProcess and use for dwCreationFlags CREATE_NEW_CONSOLE.
If you have a batch file and want to display multiple console windows, use the start command to start your console program to create a new console and disply its output there, e.g.
start cmd.exe /k dir
My application is a GUI app that has helpful (though optional) information through the terminal (via cout).
In Windows I either have a console appear (by compiling as a console app, or allocating it dynamically) or I don't.
My intention is to make use of the console IF it is being run from the console, but ignore the console completely if it was not. (Essentially what happens in Linux and OS X).
I do not wish to redirect to a file (and in the case of using cin, this is not a viable solution anyway).
Is there a way to attach a GUI app in Windows to the console it is run from, if and only if it is run from a console?
and in the case of using cin, this is not a viable solution anyway
This is the killer detail in your question. It is simple on paper, just first call AttachConsole(ATTACH_PARENT_PROCESS) to try to attach to an existing console. That will fail when your program got started from a GUI program like Explorer or a desktop shortcut. So if it returns FALSE then call AllocConsole() to create your own console.
Using cin is a problem however. The command processor pays attention to your EXE and checks if it is console mode app or a GUI app. It will detect a GUI app in your case and then doesn't wait for the process to complete. It displays the prompt again and waits for input. You will then also wait for input but you'll lose, the command processor got there first. Your output is also intermingled with the command prompt, the easy problem to solve.
There's a simple workaround for that, your user should start your program with start /wait yourapp to tell the command processor to wait for the process to complete. Problem is: nobody ever uses that. And the user will not realize what happens when they type input, intending it to go into your program but it is actually interpreted by the command processor. Producing a mystifying error message or formatting the hard drive.
Only two good ways to solve this unsolvable problem. Either build your program as a console mode app and call FreeConsole() when you find out you want to display a GUI. Or always call AllocConsole(). These are not great alternatives. The first approach is the one used by the Java JVM on Windows. One of the oldest bugs filed against the JVM and driving Java programmers completely batty from the flashing console window.
The third alternative is the only decent one, and the one you don't want, create another EXE that will always use the console. Like Java does, javaw.exe vs java.exe.
A trick is possible, you can rename that file from "yourapp2.exe" to "yourapp.com". It will be picked first when the user types "yourapp" at the command line prompt, a desktop shortcut can still point to "yourapp.exe". Visual Studio uses this trick, devenv.com vs devenv.exe.
You can check CONSOLE_SCREEN_BUFFER_INFO (via GetConsoleScreenBufferInfo) on startup to determine if you've been run from within an existing console. If the buffer's position is 0,0, you were run from outside of the console. For details, see this Microsoft Knowledgebase Article which describes the process.
In order for this to work, you need to compile your application as a console application (using /SUBSYSTEM:CONSOLE), and then detach yourself from the console if the application started a new console (buffer at 0,0). This will cause the program to properly "attach" to the calling console when launched from a command line.
As others have pointed out you have to create a console app and a window app. So, you'd end up with console.exe and app.exe. To make it less obvious at the command-line, you can take advantage of the PATHEXT trick like devenv does. cmd.exe treats a file as a command if its extension is in the PATHEXT environment variable. COM is there by default so you could rename console.exe as app.com, allowing the command app to start the console app attached to the current console.
Note: Of course, a console app can show a GUI if desired.
The difference in the build between app.com and app.exe depends on your build system but it could just be the one attribute that sets the output type. With msbuild (for .vcxproj files), it's just a matter of another build configuration.
you can create an application in console that get a line using argc and prints it;
////
int main(int argc, char *argv[])
{
//here print argv....using cout or printf
}
save the file as console.exe in the folder of your app.
now in your app if you want to see any line in console you can call the command
system("console.exe this is the line i want to print and see in console");
Is it possible to embed system command line right inside your application window?
I want to be able to have the command line take some space on the bottom of my C++ application, and my application to take the above space. Ideally it should work on Mac, Linux and Windows, but for starters Windows is the primary goal as I am developing on it.
Speaking for Windows, the Windows console window is "special" in that it gets special treatment, different than any other window on the system. You will not succeed in manipulating it for your own use. For a good example, try using Spy++ on a console window.
Note that the window created with AllocConsole is not a command-line interpreter, it's just a console window.
You should implement your own console window, and as far as interpreting the commands I can think of a few options to explore depending on what you expect, behavior-wise and complexity-wise:
Delegate commands to a hidden cmd.exe
Interpret commands yourself
There are probably open-source solutions for command line interpreting.
In Windows, you can do that using some WinAPI functions like ShellExecute and CreateProcess (there are a few others that I don't remember). You get the command string from your GUI, pass it to one of these WinAPI functions, then send the output back to your GUI.
You want to do this on multiple platforms, so I would suggest making a generic module (class or namespace of functions, whatever fits you best) that allows using the OS terminal agnostic of the actual underling OS. Then. when you want to port your app to another OS, you just change the implementation of this module.
Note: Boost has (had?) a library under development that made running shell commands easier, Boost.Process. But it's currently on version 0.4 and hasn't been updated since October 4, 2010 (even though its status is still "on going").
I need to make a windows GUI application can run in console, so I attach the console to the process when the application is invoked with a command line. However, after the application exit, the console prompt with the path doesn't show unless the ENTER key is pressed. Is there any way that the prompt with the path can directly show up without pressing the enter key? Thanks.
Short answer: This is not possible.
Long answer: Well, it is sort of possible if you are willing to relax your requirements a little bit. You basically have three options:
What you have done already. You can attach GUI application to a console but cmd.exe will not wait for your application to exit.
Create a GUI application and open console in the GUI application. The console will only last as long as you application.
Or you can restructure your application/source a bit and provide two executables, GUI one that starts GUI directly, another that is console executable.
In C#, I use SendKeys.SendWait("{ENTER}"); to do that. I think in C++, the keybd_event function does something similar.
Like Autodesk Maya with MayaBatch, you can build a small console application which basically run your GUI application with CreateProcess and wait with WaitForSingleObject.
You will have to use this "batch" version of your application in the console.
I'm creating a Win32 program that will be executed every time the computer turns on. I manage to do this by adding the .exe path into the registry. The problem is; I want to make the program appear minimized in the system tray when the computer is turned on but if I double click it [after the computer turns on and the program is not currently running] the program should appear on its normal [maximized] size.
Question, I was thinking on whether is was possible to pass an argument to the program when the program is executed from the registry. Is this possible? If yes/no, how would I manage to do this?
(Using windows XP) Thanks.
Yes, if your using HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run you can simply quote the path & add a command line:
Your App = "c:\xxxx\yourapp.exe" /mycommand
Even if it's not possible to launch your program with command line arguments from the registry, you can use a batch script to do so. Just create a batch script that launches your program with the appropriate arguments, and use the registry to run that batch script instead.
Why not put arguments on the program's shortcut instead? That way you can make the default behavor be what it does on system startup, and use the arguments on the shortcut to tell it how to behave when the user starts it.