[nonesuchluck]

ksh93 depends exclusively on the kernel implementation of /dev/fd devices. I just checked `cat <(ls)` a moment ago on both Linux and AIX 7.2--the latter fails in ksh93t+.

Bash uses /dev/fd when available, but also appears to have an internal implementation which silently creates named pipes and cleans them up. In Bash 5.0.18 on AIX, fake process substitution works just fine, in my testing.

[pgtan]

Yes, you are right. Bash 5 on AIX 7.2 works with process substitution. Thanks for the advise!