Bc

I frequently use the command-line GNU bc calculator to do quick arithmetic while debugging C programs. An ongoing annoyance is bc's insistence that the hexadecimal digits A-F must be entered in uppercase. Other software, such as GDB and printf("%p",...), output lowercase hexadecimal digits, which keeps me from cutting and pasting the values into bc. Manually typing the values can be a big time sink when I need to perform a lot of calculations.