rrdtool xport - limit on DEFs

Question

I have a script that generates command line invocations of rrdtool xport based on input provided in a domain specific language. This works well, until the number of DEFs in the command line exceed a certain number - it seems to be around 50. At that point the command simply returns without any output or error information.

Is there a limit on the number of DEFs in rrdtool export? If so, then can it be raised or circumvented?

Answer 1

The issue turned out to be the character limit on the command line sent to the shell via Python's os.system method call. The issue can be worked around by creating a temporary executable script, writing the command line to the script and executing it.