ifs seems a holdover. it's only ever used in `{} yet it's a global inherited variable. so it's easy to write a script that assumes that ifs is set to the default.
a seemingly useful way to use ifs is as a local. one would think ifs=burble fu=`{bar} would be sensible, but unfortunately this is doubly wrong. the assignments aren't local since there is no command, just assignments. this could be fixed by ifs=burble {fu=`{bar}} but if bar is a script and isn't quite careful about setting ifs before using it, bar will produce surprises. it seems to me the easiest way to fix this is to introduce a new form of `{} that allows the splitting characters to be specified without fidding ifs, so fu=`burble {bar} (fortunately rc didn't adopt byron's `word form.) this has the advantage of not breaking anything while still allowing one to write scripts more precisely. the code is contrib quanstro/rchistory. enjoy. - erik