bc flags & options

Basic usage

Evaluate an expression from a pipe.

echo "2 + 3" | bc

Load the math library (enables s(), c(), a(), l(), e() and sets scale to 20).

echo "scale=2; 10/3" | bc -l

Suppress the welcome banner in interactive mode.

bc -q

Use scale to control decimal places.

echo "scale=4; 22/7" | bc

Common pattern for shell math with decimals.

result=$(echo "scale=2; 100 * 0.15" | bc)

echo "2^10" | bc

echo "scale=4; sqrt(2)" | bc -l

Convert between number bases using ibase and obase.

echo "obase=16; 255" | bc

echo "ibase=16; FF" | bc

echo "x=5; x^2 + 3*x + 1" | bc