what is the right format of the cmd command "start"?

Question

Someone told me that if I want to use the cmd command "start" to open a file with a exe application, the format should be like this :" start "" "cai\BB2.swf" "cai\aa1.exe" ".

So I use "os.system("start "" "cai/bb1.swf" "cai/aa1.exe"")" to run it by python. Actually , it works .However ,sometimes a window asking me to find an application will appear instead of the window of "aa1.exe".When I change it into " os.system("start "cai/bb1.swf" "cai/aa1.exe"")" , the aa1.exe started,but it didn't open the bb1.swf.

What's worse, when I opened the folder in powershell and ran this command, it failed like this.

Then I changed the command into " start "cai/BB2.swf" "cai/aa1.exe" ". It worked properly.

But when I created a .bat file and wrote it down , It did't work. It became fine when I change it back to " start "" "cai/BB2.swf" "cai/aa1.exe" ".

It seemed like running command in cmd / powershell /the os.system( ) function in python can be very different.And the usage of "/"and "",and even the number of argument in the start command veried.

So why? And which is the right format , in the os.system( ) function of python and cmd shell /powershell?

Answer 1

You put the program name first and pass the file name as an argument.

In a command prompt:

start notepad.exe c:\temp\AdminTest.txt
start "My window title" notepad.exe c:\temp\AdminTest.txt
help start 

In a Powershell prompt:

start-process notepad.exe C:\temp\AdminTest.txt
start-process notepad.exe -ArgumentList C:\temp\AdminTest.txt
get-help start-process

However ,sometimes a window asking me to find an application

If you try to "start c:\temp\somefile.txt", Windows looks to see what program is associated with .txt files and launches it. You'll get that prompt if there is no program associated with the file extension.

So I use "os.system("start "" "cai/bb1.swf" "cai/aa1.exe"")" to run it by python.

Start is a cmd.exe command. There is no start.exe. I don't have Python installed but I would expect one of these options would work. The first example might cause python to hang while aa1.exe is running. You will just have to test.

os.system("cai/aa1.exe cai/bb1.swf")
os.system("cmd.exe /c start cai/aa1.exe cai/bb1.swf")

You may also need to specify the full path to the files. (C:\SomeFolder\cai\aa1.exe)

Python's os module may implement it's own start command. I've seen examples like os.system('date'), which I would normally not expect to work because there is no date.exe program. Again, I don't have python installed to be able to test.

https://www.w3schools.com/python/module_os.asp