On May 8, 2008, at 8:06 AM, Josh Hursey wrote:
--> If not intended to be used by users (i.e., it's an internal
mechanism only), is there a reason why we're not using a zero-length
string (e.g., mpirun --mca foo "")?
I think a zero length string might get confusing with the empty
string. The empty string is taken to mean auto-select from all
available components, which currently cannot be specified on the
command line as an -mca option. The 0 length string is close and
nearly indistinguishable in an (A)MCA file from a NULL string.
Ah, right. Should we introduce another keyword, "all"? This would
then be symmetric to "none" and could be the default value. An empty
string would then be an error.
Per the larger issue, I wonder if we should simply disallow NULL
default string parameter values. This might simplify a lot of things...
--
Jeff Squyres
Cisco Systems
