Re: OpenRead crashes System 7
- To: mathgroup at yoda.physics.unc.edu
- Subject: Re: OpenRead crashes System 7
- From: withoff
- Date: Tue, 23 Nov 93 16:08:53 CST
> Dear MathGroupers:
> I have just found a way to crash Macintosh System 7.1 with the Mma 2.2.1
> operator OpenRead. It's not much fun, but here are detailed instructions
> for those who might like to try it:
>
> 1. Use FileNames["*xxx*",$Path,Infinity] to locate all files in your home
> directory that have xxx anywhere in their name. (I assume $Path still has
> its automatically initialized value).
>
> 2. Use control-t to unformat the return, and copy out the desired
> pathname, including its surrounding quote marks. If it is long enough to
> have a line continuation in it, take out the \, the carriage return(s), and
> any extraneous spaces. Paste it on the right in
>
> dataPath = "<<path from current directory to desired file>>"
>
> 3. Verify dataPath with FileDate[dataPath]. When you have the dataPath
> correct, the date of last alteration of your data file be returned.
>
> 4. Now issue OpenRead[dataPath]. Mma will go into a seemingly endless
> loop, it will not abort, the cursor will be dead or disabled, and all you
> can do is hit the reset button.
>
> OpenRead["fileNameOnly] does work if you do one of the following:
>
> (1) Prepend to $Path the path to the directory that directly contains the
> desired file, or
>
> (2) Use SetDirectory to change the current directory to the subdirectory
> that directly contains the desired file. (I find this awkward, since
> SetDirectory seems to work only one level at a time. Even DOS did better
> than that! But this is a separate complaint...).
>
> Regards- Martin
I'm afraid I wasn't able to duplicate any of this. The functions involved
quite quickly call Macintosh system and C library functions, and the only
known problems are related to differences in file naming conventions.
I have a hard time imagining how this could crash a computer unless
the system or the C library or the file being opened is somehow messed up.
SetDirectory also worked fine when I tried things like
SetDirectory[":Packages:Statistics:Common"]
(or whatever the proper Macintosh pathname separator convention is).
This sounds like a question that could be sent to our technical
support department (support at wri.com).
Dave Withoff
Research and Development
Wolfram Research