4 ms·
Programmer's Calculator
- kazinator 9y agoPOSIX syntax, entered into BusyBox shell (not even Bash or anything), running __on__ an ARM embedded system: # echo $(( (0x0110 << 14) & 0xDEADBEEF )) 262144 # printf "%x\n" 262144 40000 Now let's make a calculator REPL out of these: # while read expression ; do eval "result=\$(( $expression ))"; printf "dec = %d, hex = %x\n" $result $result ; done 2 + 2 dec = 4, hex = 4 a=3 dec = 3, hex = 3 b=4 dec = 4, hex = 4 a + b dec = 7, hex = 7 (a + b) << 3 dec = 56, hex = 38 [Ctrl-D][Enter] #