pipeProcess, interactions with stderr ... I am missing something here

[Ali Çehreli]

On 8/30/21 9:35 AM, james.p.leblanc wrote:
 > D-ers,
 >
 > I am attempting to use pipeProcess for interacting with an external
 > process.
 > My simplified routine can work somewhat.  But, trying to print any 
messages
 > that process writes to stderr yields the message:
 >
 > (master) gnuplot > gnuplot_example
 > **core.exception.InvalidMemoryOperationError at src/core/exception.d(647):
 > Invalid memory operation**

That error almost always means you are allocating memory in a 
destructor, which sometimes is presumably due to using parts of your 
object that have already been finalized by the GC. (Or, the GC has 
already been terminated? I am not sure.)

In this case, converting your ~this to a named function solves the issue:

   // Was: ~this()
   void close() {
     // ...
   }

// ...

   auto gp = new Gnuplot();
   scope (exit) {
     gp.close();
   }

Ali