What is the numeral for base greater than 16 in bc?

Question

I recently read about bc and found that it supports obase upto 999. Can anyone point me to the numeral set for bc for base greater than 16.

the decimals from 0 to ($base minus one)? echo "obase=20; 20" | bc, echo "obase=20; 39" | bc, echo "obase=20; 40" | bc — Jeff Schaller, Jul 12 '17 at 18:45
So, it is a space separated decimal numbers for each digit ? — Palash Kanti Kundu, Jul 12 '17 at 18:50
It wouldn't have been particularly difficult for you to try this out yourself. — Chris Davies, Nov 25 '18 at 17:20

score 6 · Answer 1 · answered Jul 12 '17 at 18:56

This is covered in the manual page for bc:

For bases greater than 16, bc uses a multi-character digit method of printing the numbers where each higher base digit is printed as a base 10 number. The multi-character digits are separated by spaces. Each digit contains the number of characters required to represent the base ten value of "obase-1".

score 1 · Accepted Answer · answered Jul 12 '17 at 19:51

Yes, bc can process numbers with bases up to 999.

As an example:

$ echo "ibase=10;obase=40;3*40^2+7" | bc
03 00 07

Or, as it should be "307" = 3*40^2 + 0*40^1 + 7*40^0. Or 4807 in decimal.

$  echo "ibase=10;obase=10;3*40^2+7" | bc
4807

So, the values are printed as a two digit (decimal) number with an space as separator.
Some other example:

$ echo "ibase=10;obase=530;371*530^9+222*530^3+127" | bc
371 000 000 000 000 000 222 000 000 127

Or, maybe (in bash), the same number:

$ bc <<<"obase=530;1224212292558591376050694127"
371 000 000 000 000 000 222 000 000 127

What is the numeral for base greater than 16 in bc?

2 Answers2