Newly created scripts?

[John W. Eaton]

On 24-Feb-2010, Mikhail Zotov wrote:

| Hello everybody,
| 
| I am observing a strange behaviour of Octave-3.2.3 and 3.2.4 with
| newly created files (i.e. those that do not exist at the moment a
| script is started). Please, consider the following example:
| 
| # testrun.m
| 
| clear
| delete("testfile*")
| 
| filename0 = "testfile";
| 
| for i=1:9,
|       filename  = [filename0 int2str(i)];
|       diaryname = [filename0 int2str(i) ".m"];
|       opendiary = ["diary " diaryname];
| 
|       if exist(filename,"file")==2,
|               delete(diaryname)
|       else
|               disp("Nothing to delete")
|       endif
|       disp([diaryname " does not exist"])
| 
|       eval(opendiary)
|       disp(["i=" int2str(i)])
|       diary off
|       disp([diaryname " created"])
| 
|       if exist(diaryname,"file")==2,
|               eval(filename)
|               disp([filename " evaluated"])
|       else
|               disp("oops"), break
|       endif
| endfor
| # EOF
| 
| When I run it for the first time, I get:
| 
| octave:1> testrun
| error: no such file, `/path/to/testfile1.m'
| error: called from:
| error:   /path/to/testrun.m at line 13, column 2
| 
| The next run:
| octave:2> testrun
| warning: delete: no such file: testfile*
| Nothing to delete
| testfile1.m does not exist
| i=1
| testfile1.m created
| i =  1
| testfile1 evaluated
| Nothing to delete
| testfile2.m does not exist
| i=2
| testfile2.m created
| error: `testfile2' undefined near line 2 column 1
| error: called from:
| error:   /path/to/testrun.m at line 26, column 3
| 
| Then run `in cycle' sometimes breaking at testfile3.m
| 
| If I comment `delete("testfile*")' at the beginning of the script and
| make sure there are no testfile?.m in the Octave path, the situation
| changes: on the first run, the script breaks at testfile2, on the
| second run it breaks on testfile3, etc. Noticeably, `ls testfile*'
| shows that the `missing' file actually exists (as does
| `exist(...,"file")==2'!
| 
| I am sure all this worked in Octave releases prior to 3.2.x.  Is this
| a new feature? If so, what can I do to overcome it?

I can't duplicate this rpoblem with the current sources, so I guess
the problem has been fixed in teh development version of Octave.

But what are you really trying to do, and why are you using the diary
and eval to do it?  Maybe there is a better way to do what you want
that doesn't rely on such odd tricks.

jwe