The usual way to launch a file is to use
which opens the file in the default program
registered to handle that type of file.
But what if you want to override the default?
some time ago
that if you know the ProgId of the program you want to run,
you can specify it in the
lpClass of the
to force the file to be treated as if it were a specific
kind of file.
Okay, but what if you aren't sure that the program you want to run has registered a ProgId at all? Or if you don't know what that ProgId is? For example, maybe you searched the hard drive for executable files and put them all in a list, and let the user pick one, and then you want to run that program to open the file.
In that case, you are in a bit of a pickle because
you don't know how an arbitrary program expects its
command line to be formatted in order to open a file.
Fortunately, most programs which can open files will
accept the file name on the command line with no other
so you will have a high chance of success if you
simply enclose the name of the file you want to open
in quotation marks (in case it contains spaces),
and then pass that as the command line.
equal to the program you want to run,
equal to the file you want to open,
enclosed in quotation marks if necessary.
Exercise: Does the path to the program need to be fully-qualified?
Exercise: Why do you have to quote the file you want to open, but not the program itself?
One reason you may want to use
instead of just going straight to
is if you need elevation.
You can pass
to do the work of prompting the user for elevation.