Does bc support hex calculations?

Question

I'm trying to do a hex calculation directly with bc, I already specified the scale.

echo 'scale=16;c06b1000-c06a5e78' | bc

But I still get a zero. What could be wrong?

score 47 · Accepted Answer · edited Jan 10 '19 at 14:45

47

echo 'ibase=16;C06D1000-C06A5E78' | bc
176520

Note that only UPPER CASE hex digits are supported as lower case ones would conflict with function and variable names, which is why you got 0 in your example (var1 - var2)

If you need the answer in hex too, just set the obase variable:

echo 'obase=16;ibase=16;C06D1000-C06A5E78' | bc
2B188

PS: FYI scale isn't designed for conversion base. From man bc:

scale defines how some operations use digits after the decimal point.
The default value of scale is 0.

edited Jan 10 '19 at 14:45

Roland

115
5

answered Oct 04 '12 at 07:07

rush

27,055
7
87
112

So the real answer on 'what could be wrong' is that bc only supports UPPER CASE for the hex digits, with credits to editor Stephane. – Roland Jan 10 '19 at 10:23
5

Note that it's important to set `obase` before you set `ibase`. If you set `ibase` first, then it affects the value parsed for `obase` too. ie `ibase = 16; obase = 16;` sets `obase` to 0x16 = 22 – Arnavion Dec 10 '19 at 01:41

Does bc support hex calculations?

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