Launching Wordpad on Windows

[Patrick L. Nolan]

I'm trying to find a clean way to launch a Wordpad editor
on Windows. By "clean", I mean that it should work on as
many versions of Windows as possible, and it shouldn't
require installing any extra software. I assume everyone
has win32api and its friends.

The problem is to find the path to wordpad.exe. At first
I just copied the path from my XP machine:
c:\Program Files\Windows NT\Accessories\WORDPAD.EXE

I verified that the same path works on W2K, but I don't
know about older versions. With some labor I was able
to come up with a longer, more obfuscated bit of code:

item = "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\App Paths\\WORDPAD.EXE"
key = win32api.RegOpenKey(win32con.HKEY_LOCAL_MACHINE, item, 0,
win32con.KEY_QUERY_VALUE)
info = win32api.RegQueryValueEx(key, None)
win32api.RegCloseKey(key)
editor = win32api.ExpandEnvironmentStrings(info[0])

I would like to solicit learned opinions about this. Which
version will work in more versions of Windows? Is there a
better approach?

--
* Patrick L. Nolan *
* W. W. Hansen Experimental Physics Laboratory (HEPL) *
* Stanford University *

[Adonis]

"Patrick L. Nolan" <p...@razzle.Stanford.EDU> wrote in message
news:buhtvp$l0j$1...@news.Stanford.EDU...

This works for me:
(Using WinXP Pro)

Python 2.3.3 (#51, Dec 18 2003, 20:22:39) [MSC v.1200 32 bit (Intel)] on
win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.system("start wordpad")
0

Hope this helps.

Adonis

[Michael Geary]

> > I'm trying to find a clean way to launch a Wordpad
> > editor on Windows. By "clean", I mean that it should
> > work on as many versions of Windows as possible,
> > and it shouldn't require installing any extra software.
> > I assume everyone has win32api and its friends.
> >
> > The problem is to find the path to wordpad.exe. At
> > first I just copied the path from my XP machine:
> > c:\Program Files\Windows NT\Accessories\WORDPAD.EXE
> >
> > I verified that the same path works on W2K, but I
> > don't know about older versions.

Never hard code a path like that. It definitely won't work on all versions
of Windows. It won't even work on all XP systems. The Program Files
directory isn't always on the C: drive!

> > With some labor I was able to come up with a
> > longer, more obfuscated bit of code:
> >

> > [code using the App Paths registry key]

> >
> > I would like to solicit learned opinions about this.
> > Which version will work in more versions of
> > Windows? Is there a better approach?

You can do it with App Paths, but that's way too much work. It's not the
Windowsonic way to do it. :-)

> This works for me:
> (Using WinXP Pro)
>

> >>> import os
> >>> os.system("start wordpad")
> 0
>
> Hope this helps.

I wouldn't recommend os.system. The problem is that it starts a command
shell. You didn't notice this because you're testing from a console window,
so the secondary command shell runs in the same console window you're
already using. But if you put this code in a non-console app, it will open a
new console window in addition to the WordPad window. That window will close
right away because you're using the 'start' command, but it's extra screen
activity you don't want.

So what's the right way to do it? The underlying Windows function you're
looking for is ShellExecute(). That's the easiest way to launch an app. It
knows all about App Paths and the environment PATH. It's the same function
that gets called if you do a Start/Run... in the Windows UI.

You can use win32api.ShellExecute, or better yet, the os.startfile function
calls ShellExecute, so you don't even need win32api:

>>> import os
>>> os.startfile('wordpad.exe')

-Mike

[Gabriel Genellina]

At 20/1/2004 00:50, you wrote:

>item = "SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\App Paths\\WORDPAD.EXE"
>key = win32api.RegOpenKey(win32con.HKEY_LOCAL_MACHINE, item, 0,
> win32con.KEY_QUERY_VALUE)
>info = win32api.RegQueryValueEx(key, None)
>win32api.RegCloseKey(key)
>editor = win32api.ExpandEnvironmentStrings(info[0])
>
>I would like to solicit learned opinions about this. Which
>version will work in more versions of Windows? Is there a
>better approach?

I think this is the best way. Untested, but that should work even on Windows95.
Anyway, you could provide a default (simply WORDPAD.EXE), just in case the
application exists and is in the path but is not registered.

Gabriel Genellina
Softlab SRL