For 'confess', it is trivial:
% perl -MCarp=confess -e"confess 'this ', 'is split'" this is split at -e line 1
If it isn't something that can deal with a list of strings, then I use join the vast majority of the time (because '.' has lousy precedence for such, 'sprintf' quickly leads to action-at-a-distance, '<<' can't be sanely indented, etc.).