After I had modified our configuration to support AIX and IRIX, I was surprised to start receiving DfChkEmergency alerts from the IRIX test host. After looking at the input data, I readily saw the problem.
Spot the difference? Under Solaris (and all the other supported non-IRIX OSes), the "Capacity" or "%use" figures are all displayed as percents (e.g., "52%"), while in IRIX alone the trailing percent sign (%) is missing (e.g., "22").
So, the #cap for /dev/root was "22", that is, 2200%, and the alarm got triggered.
//      rule    // irix displays "100", not "100%"
As the comment says, this won't work, because I am trying to set anew a fixed dat value, which to pikt is a no-no.
then refer to #usage, not #cap, in all subsequent rules.
input proc "=dfl | =grep '^/'"
#if irix        // irix displays "100", not "100%"
$1, $2, $3, $4, $5, $6, $7)}'"
with the "%" now consistently applied.
After that, the rest of the alarm worked as is. And no more erroneous alerts!