RE: "unable to open pipe" problem

[John W. Eaton]

On 26-Feb-1999, George White <address@hidden> wrote:

| With octave, at least on SGI, once you have allocated memory it does not
| get released until the program exits.

Octave does free memory when it runs, by calling either the C++
operator delete or the C function free.  Whether that returns memory
to the operating system for other programs to use or just makes space
available for Octave to reuse depends on the implementation of the
allocator on your system.  On most traditional Unix systems, I believe
that calling free doesn't return memory to the OS.

| My work typically uses 20M
| arrays.  It is not unusual to see about the same profile you report:  in
| the process of transforming input array A to output array B the total
| allocation for octave grows to around 200M, but at the end only the array
| B is left in all that memory and popen fails.  The result is that I have
| to write B to a file and then process it with the program that generates
| the final output format.  Having to exit octave plus the extra disk I/O
| means the task takes significantly longer than it would if popen was
| available (and negates one of the advantages of octave over matlab!).

If you think there is a bug in Octave, can you please send a precise
bug report that includes enough information to reproduce the problem
ot address@hidden

Thanks,

jwe