I had a need the other day for dealing with some really big numbers. Unfortunately, the machine I was using did not have mpexpr installed. Woe is me. Until I came up with the following fast and very dirty workaround. Works on Unix systems and Windows systems with Cygwin:
proc mpexpr { args } {
return [ exec echo $args | bc -l ]
}
% mpexpr 12342342354564636*94852304570297207525
1170699616126044020647089347918085900Is it a cheat? Well, yeah, it's a cheat. But it was darn handy!
CMcC I've written bignum, a quick critcl wrapper for libgmp, giving arbitrary precision ints and floats.
Sarnold I have written a little library for multiple precision arithmetics, in pure Tcl : see MPA. It should be cross-platform, although I have tested it only on Windows with ActiveTcl.
DKF: Time to learn a bit more exec magic:
proc mpexpr args {
exec bc -l <<[join $args]
}