DECC$PIPE_BUFFER_SIZE

   The system default buffer size of 512 bytes for pipe write
   operations can limit performance and generate extra line feeds
   when handling messages longer than 512 bytes.

   DECC$PIPE_BUFFER_SIZE allows a larger buffer size to be used for
   pipe functions such as pipe and popen. A value of 512 to 65535
   bytes can be specified.

   If DECC$PIPE_BUFFER_SIZE is not specified, the default buffer
   size 512 is used.

   Default: 512

   Minimum: 512

   Maximum: 65535