On Sun, Sep 06, 2020 at 01:18:22PM -0700, L A Walsh wrote: > > as it's pure & directly viable in PS1 env. var. > > PS1=`echo \!` > --- > Doesn't work if you don't have '!' support (I generally found > '!' more often did unwanted things, but I never used csh):
You're talking abuot csh-style history expansion (set -o histexpand), right? That has nothing to do with the expansion of \! within PS1. I've got histexpand disabled, and PS1='\! ' gives the number just fine.
