OpenEuphoria

Re: Opening a file - File Open Dialog spoils future code

• Posted by Andy Drummond <andy at kest?el?ele.com> Jan 16, 2008
• 516 views

CChris wrote:
> 
> Matt Lewis wrote:
> > 
> > CChris wrote:
> > > 
> > > open() doesn't understand Windows folders, because Windows doesn't have a
> > > notion
> > > of a current directory. open() uses the PATH environment variable, which
> > > is
> > > a DOS/Unix thing Windows supports for backward compatibility only) and
> > > looks
> > > for MyFileName.CFG in places completely different from where Windows looks
> > > for
> > > them, so it probably just can't see the file there.
> > 
> > I thought that it did, and that %PATH is only used for executables and for
> > dlls.  What do current_dir() and chdir() do then?
> > 
> > Matt
> 
> All right, I should have checked first, but the bottom line is the same: never
> use current_dir() under Windows. Here is what I found on MSDN:
> <quote>
> The directory at the end of the active path is called the current directory;
> it is the directory in which the active application started, unless explicitly
> changed. An application can determine which directory is current by calling
> the GetCurrentDirectory function.
> 
> An application can change the current directory by calling the
> SetCurrentDirectory
> function.
> </quote>
> 
> I have recently wondered why I wasn't finding ex.err after a program crash.
> Searching ex.err on my machine reported 9 different directories, some of which
> I'd havd never thought about. Since ex.err is created using
> open("ex.err","w"),
> I consider the "current directory" to be undefined for practical use: it is
> defined, but as something volatile (what is the active application on a
> multiprocess
> platform?). I'd go as far as recommending to drop support of current_dir() and
> chdir() under Windows.
> 
> CChris

I disagree CChris.  There IS such a thing as the current directory; just because
a program can change it doesn't make it less valid.  Ex.err gets dumped into
the current directory, which is why it is a good idea to use crash_file() to
be sure your ex.err gets put where you want.  The current directory is where
the file system performs actions unless otherwise instructed. If I say something
like open("fred.fil","r") Windows will attempt to open that file in the current
directory - where ever that may be.  Current directory is simply a default
folder
to access in the absence of further information. I get and set current directory
all the time; if you took them out I'd put them into my own library!!

AndyD