String calculator

[test tube baby]

Are there any opensource c++ string calculators available for Linux? I know it is easy, but I do not wish to build one myself. I'd like a string calculator which will process a string such as "x+2*5" to "x+10", and so on. It should do add/subtract, mul/div, exponent, log, etc.

I'd like to modify the source code too, and also include it in my own software.

Does anybody know of any?

[kbw]

http://linux.die.net/man/1/bc