On Dec 30, 2010, at 2:58 PM, Don Guinn wrote:
> If the purpose is to read the file if it exists, just go ahead and use fread
> which will return _1 if the file does not exist. Just test for _1 after the
> fread.
On Dec 30, 2010, at 3:40 PM, Devon McCormick wrote:
> Won't "fread" also return _1 for an existing file that cannot be read?
Here is the "fixed" code in the gnuplot package:
> NB. =========================================================
> NB. following builds a shell script for running gnuplot
> gphost=: 3 : 0
> f=. jpath '~temp/shell.sh'
> if. fexist f do. 1!:55 <f end.
> y=. y, LF -. {:y
> y 1!:2 <f
> 'rwx------' 1!:7 <f
> 2!:0 f
> NB. If you delete shell.sh here, it's gone before it can execute
> )
The original author (ceb 2006, I believe) couldn't get this to work, and it was
because (s)he did the sensible thing here:
1) create a temp file
2) write some data into it
3) change its permissions
4) execute it
5) delete it
What seemed to be happening, in my case, at any rate, was that (5) would occur
before (4) and there would be no shell script to execute gnuplot.
So, not the most elegant fix, but I leave the file, and simply delete before
writing the new one. I believe that delete returns an error if the file's not
found, so I need to test for the first use, where the wouldn't be a file yet.
As I said, none of this is very elegant, but it did get gnuplot to work on j701
on Darwin, which to me is preferable to GTK. Improvements to come...
Best wishes, Charles
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