Under Windows 7, I need to run a file, say "file_name", with myapp.exe through a command line. When I call myapp and file_name with their full paths, it opens a new instance of myapp (it is not single-instanced). Is it at all possible to use a running instance of myapp, if there is one (as if I just dragged and dropped file_name into myapp's window) ?
I know how to check if myapp.exe is already running using tasklist. But in case there is a running instance, I don't know I can get some kind of application handle through which I can call file_name, without opening a new myapp.exe.
Thanks!
Related
In a Windows batch file, or in the Command Prompt, what's the difference between calling start mspaint, for example, and mspaint? They appear to do exactly the same thing.
Another example, where all 4 cases appear to do the same thing. Can you please help me understand what are the subtle differences, if any?
taskmgr
C:\Windows\System32\Taskmgr.exe
start taskmgr
start C:\Windows\System32\Taskmgr.exe
Follow-up: it looks like start opens a separate background command prompt to run the program you write after it (source: https://technet.microsoft.com/en-us/library/cc770297(v=ws.11).aspx). Is this the same as Linux's myApp & format--where you have the & suffix?
Starting a Program
See start /? and call /? for help on all three ways.
Specify a program name
c:\windows\notepad.exe
In a batch file the batch will wait for the program to exit. When
typed the command prompt does not wait for graphical
programs to exit.
If the program is a batch file control is transferred and the rest of the calling batch file is not executed.
Use Start command
start "" c:\windows\notepad.exe
Start starts a program and does not wait. Console programs start in a new window. Using the /b switch forces console programs into the same window, which negates the main purpose of Start.
Start uses the Windows graphical shell - same as typing in WinKey + R (Run dialog). Try
start shell:cache
Also note the first set of quotes, if any, MUST be the window title.
Use Call command
Call is used to start batch files and wait for them to exit and continue the current batch file.
With Reference to Start and just typing a program name.
Help Windows Find Programs and Documents
Programs and documents can be added to the registry so typing their name without their path in the Start - Run dialog box or shortcut enables Windows to find them.
REGEDIT4
;The bolded name below is the name of the document or program, <filename>.<file extension>
[HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\App Paths\IE.txt]
;The # means the path to the file is assigned to the default value for the key.
;The whole path in enclosed in a quotation mark ".
#="\"C:\\Program Files\\Internet Explorer\\IE.txt\""
;Optional Parameters. The semicolon means don't process the line. Remove it if you want to put it in the registry
;Informs the shell that the program accepts URLs.
;"useURL"="1"
;Sets the path that a program will use as its' default directory. This is commented out.
;"Path"="C:\\Program Files\\Microsoft Office\\Office\\"
For a technical discussion.
CMD preprocesses commands and finds the file then calls CreateProcess. Start - Run dialog or the Start command uses ShellExecuteEx which eventually calls CreateProcess.
This is CreateProcess rules - note CMD provides full paths to CreateProcess. https://msdn.microsoft.com/en-us/library/ms682425
1.The directory from which the application loaded.
2.The current directory for the parent process.
3.The 32-bit Windows system directory. Use the GetSystemDirectory function to get the path of this directory.
The 16-bit Windows system directory. There is no function that obtains the path of this directory, but it is searched. The name of this directory is System.
5.The Windows directory. Use the GetWindowsDirectory function to get the path of this directory.
6.The directories that are listed in the PATH environment variable. Note that this function does not search the per-application path specified by the App Paths registry key. To include this per-application path in the search sequence, use the ShellExecute function.
ShellExecuteEx is here https://msdn.microsoft.com/en-us/library/bb759784(v=vs.85).aspx
CMD preprocessing is available on my Skydrive - originally from MS web site but no more. See Windows NT Command Shell Ch 2 https://1drv.ms/f/s!AvqkaKIXzvDieQFjUcKneSZhDjw
you need to call start application when you want the application to launch and return immediately to the command shell for further commands.
(on Linux, closest equivalent of start is the & suffix)
Some commands have the ability to do that without start prefix. That's what you're experiencing.
On the other hand, if you want an application returning immediately to "block" the shell, prefix by cmd /c
Try cmd /c taskmgr for instance, you'll see it blocks the command window until you quit it.
About the question about taskmgr, the 3 possibilities amount to the same result:
taskmgr is in system path: with or without full path the system finds it
taskmgr returns to the command window immediately. In that case, start is redundant.
I'm writing myself a GUI utility for use in a CMD window to navigate between folders,
rather in the style of the old Norton Change Directory utility for DOS.
When run, the app pops up a folder tree to allow the user to select a folder to which
to navigate and then closes and returns to the CMD prompt. At the moment, the way it
works is that it is run as the first command in a "main" batch file. It writes a secondary batch
file, in my app's folder under AppData, containing the commands to change drive and
directory to the folder the user selected, and the main batch file then invokes this
second batch file using CALL.
It works fine, but this way of actually changing the CMD window's current directory
strikes me as inelegant both from the point of view of needing to be run from a batch file
(so that the user's selection can be acted upon after my app has closed) and of
needing the secondary batch file to do the actual navigation.
So, my question is, how can my app send the instructions to the instance of CMD
that owns the window in which the app is run to the folder the user selected? I've tried doing a ShellExecute
of "CMD /K ..." but although that does indeed navigate to the
selected folder, it does so in a new CMD window, not the one my app is run in. The
conceptual gap I have is how to get the current CMD to act on my app's instructions
after my app has terminated.
Fwiw, I thought of trying to write the user's folder selection into an environment variable in the CMD window's environment for the CMD processor to
act upon from there, but this seems to require that the CMD window be opened via "Run as Administrator", which I definitely don't want.
Your program cannot influence the environment variables of the command interpreter because they're separate processes. Your program cannot change the directory of the command interpreter directly, either, because, again, they're separate processes.
You need to use a batch file because the command interpreter executes batch files internally. Since it's all the same process, the batch file has the power to change the current directory, and for that change to remain in effect after the batch file finishes running.
Therefore, you need some way for your interactive program to communicate the directory selection back to the batch file so that it can act on it.
Instead of writing the instructions to another batch file, you could write the result to standard output. Have the batch file capture that output into a variable, and then execute cd on that variable. The batch code would look something like this:
for /f "tokens=*" %%a in ('[select_dir.exe]') do (
set DIRSELECTION=%%a
)
cd /d %DIRSELECTION%
Your Delphi code would look like this:
writeln(selected_dir);
To allow that command to work, you'll need to make sure your program is marked as a console program, as with {$APPTYPE CONSOLE}. If it's not, then the batch file won't receive any output, and probably won't even wait for your program to finish running before proceeding. It's OK for a console program to display a TForm, just like a GUI program.
system( "start /wait file.docx")
This starts the file but fails to wait if another docx file already open. Works perfectly if there is no file open.
What I am trying to do : I would like to open a file in windows with its default editor and wait for the user to input and do some changes to the file post save, hence I am using
/wait.
Thanks for any tip?
The default behaviour in winword is to reuse existing instances of the executable to open multiple documents. So, the second open file operation delegates its work into the existing one and exits, so the start command returns.
One usual option is to use COM to open the file and test for closing of the instance. But i know nothing of ruby or if it supports COM.
The best approach will be locate the winword executable and call it directly using as paramenters /w filename.docx to force opening the file into a new instance.
It is very stupid that windows will not let you add batch files to your quick launch or whatever they call in in windows 7. That bar across the bar, i can attach firefox there, command prompt, even paint (my favorite), but not a batch file. I can "pin" it to another program, which is just weird. I want it to standalone, the batch file does enough work by itself.
So lets say i have batch file. What is the simplest executable program I can write to invoke said script. Then I can finally pin all my useful batch files on that quick-jump-pin-bar.
If I remember right, you can do this by first pinning a shortcut to CMD.exe to the taskbar. Then edit the command, and change CMD.exe to CMD.exe /c MyBatchFile.bat. I believe this will execute the batch file.
Since you can only pin one cmd, here's an alternative, assuming you have the .NET framework installed - a very simple C# application:
Populate a textfile with the following contents:
class Program {
static void Main() {
System.Diagnostics.Process.Start(#"c:\test.bat");
}
}
where Program is the name of the executable you want to create, and c:\test.bat is the full path to the batch file. Save the file as Program.cs. Execute the following from the command line:
c:\Windows\Microsoft.NET\Framework\v2.0.50727\csc.exe Program.cs
You can replace 2.0.50727 with whatever directory exists on your machine - might be 1.1.something or 3.5 or 4.0.something - it's all the same for this scenario.
This will generate Program.exe. You can put that exe file wherever you want, and pin that executable to the taskbar. You can discard the .cs file once you're done making your executables.
Kind of a crappy solution, but it should work, assuming you don't find anything better. And if you don't have the .NET framework (which I'm not sure is even possible in Windows 7), you can install it pretty easily.
The easiest way is to create a folder, put your batch files in it, and pin the folder to the menu bar :D
You can also write a startup script, so the batch file will be executed on startup, but I don't know if you want to run those scripts on every bootup... You can also add the command prompt to the bar, and edit the startup path..
Use command switches on CMD.exe.
cmd.exe /c "myscript.bat"
As a sort of workaround you could use the following trick. Pin an arbitrary application to the task bar, Shift+right click on the pinned icon, select Properties, change 'Target' and 'Start in' accordingly. Rename it too if you like.
You can pin more than one .bat file using this technique.
I have a program that changes my desktop wallpaper by dragging the picture file onto it. I also have a wireless network program that can auto open programs everytime it connects to a certain network.
I want to change my desktop everytime it connects to a certain network, but running the wallpaper program doesn't do anything unless I drag the picture onto it. However, I can also run a cmd prompt "c:/program.exe picture.jpg"
I tried creating a batch file START C:/PROGRAM.EXE PICTURE.JPG, but it doesn't work.
So basically I am trying to create a program that can run the cmd prompt "c:/program.exe picture.jpg" - can you help, please?
Remove the "start" from the batch file, and make sure any paths with spaces in them are enclosed in quotes, otherwise they'll be broken into arguments.
For example:
"C:\Program Files\MyProgram.exe" "C:\Documents and Settings\Me\MyPicture.jpg"
A batch job should work. Try skipping that START from your example.
Start - Run - Type :
cmd /c "start /max ""C:\Program Files\MyProgram.exe"" ""C:\Documents and Settings\Me\MyPicture.jpg""" .
The cmd /c - starts a new cmd instance and quits