OpenEuphoria

Re: program directory

• Posted by Nick <metcalfn at ALPHALINK.COM.AU> Apr 22, 1999
• 504 views

Thanks Ralf.  I suspected there was something I had overlooked, and that was
indeed it.

--Nick

Ralf Nieuwenhuijsen wrote:

> > A question:
> > I have been wondering for a while now, how does one find out the
> > directory a program is in when it was run?  Not the directory it was run
> > from, given by current_dir() or the location of ex.exe given by
> > examining the command_line() (the program is not bound), but the
> > location of the .ex file itself.
>
> include misc.e
> constant cl = command_line ()
> sequence s
> s = reverse(cl[2])
> if find ('\\', s) then
>     s = s[find('\\',s)..length(s)]
> end if
> puts (1, "The directory of the .ex file or the .exe file (when bound) is: " &
> reverse (s) & '\n')
>
> -- An explenation:
> -- Command line always returns at least a 2-element-sequence.
> -- { path_name_of_interpreter , path_name_of_code , ...}
>
> With bound files, where the path and filename of the interpreter is the same
> as that of the code, the first two arguments are
> the same. With unbound file they are not. Most likely it will be something
> like ..
>
> { "c:\\euphoria\\bin\\ex.exe" , "c:\\projects\\progs\\frog.ex", ...}
>
> > for example..
> > I have a program, frog.ex  in the directory c:\euphoria\progs\frog.  It
> > needs a data file in the same directory.
> > Say a friend of mine gets the program, installs it in windows and
> > double-clicks on the .ex icon.  (he has .ex files calling ex.exe)  My
> > program will then look in c:\windows or some other strange place for
> > it's data file, exiting ungracefully when it can't be found.
>
> This is what 'pifs' are really for. You can tell windows for an dos-executable
> what the 'target'-directory must be.
> This is the default directory that applies when opening files without any
> path.
>
> > I am reluctant to specify an absolute path to the data file, after all
> > programs that force install into a particular directory kind of suck,
> > huh.  I can't tell my friend to change his system configuration either,
> > just to run my program? no way!
>
> > I hope I have overlooked the obvious.  Most of us appear to be content
> > with looking in the current directory, or relative to it for data and
> > images, hoping the user hasn't typed something like
> > c:\>ex c:\euphoria\progs\frog.ex
> > as I suspect happens sometimes, well maybe not, but windows does this
> > kind of thing and one can't guarantee it won't happen after all.
>
> Well, anyways, thankfully Euphoria _is_ quite capable of telling us the
> source-directory.
> Good luck with your program.
>
> Ralf