Call strace with the -f option to have it trace forked processes as well (i.e. the js interpreter).

Comparing the output you get with what you get when doing the same steps interactively, would certainly help to figure out what's different. In particular look for the read(0, ...) calls from the subprocess.

In reply to Re^5: Diagnosing blocking io (or: finding the WHY of my Open2 woes). by almut
in thread Diagnosing blocking io (or: finding the WHY of my Open2 woes). by Socrates

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