math

Evaluate a mathematical expression.

math(EXPR <variable> "<expression>" [OUTPUT_FORMAT <format>])

Evaluates a mathematical <expression> and sets <variable> to the resulting value. The result of the expression must be representable as a 64-bit signed integer. Floating point inputs are invalid e.g. 1.1 * 10. Non-integer results e.g. 3 / 2 are truncated.

The mathematical expression must be given as a string (i.e. enclosed in double quotation marks). An example is "5 * (10 + 13)". Supported operators are +, -, *, /, %, |, &, ^, ~, <<, >>, and (...); they have the same meaning as in C code.

Added in version 3.13: Hexadecimal numbers are recognized when prefixed with 0x, as in C code.

Added in version 3.13: The result is formatted according to the option OUTPUT_FORMAT, where <format> is one of

HEXADECIMAL

Hexadecimal notation as in C code, i. e. starting with "0x".

DECIMAL

Decimal notation. Which is also used if no OUTPUT_FORMAT option is specified.

For example

math(EXPR value "100 * 0xA" OUTPUT_FORMAT DECIMAL)      # value is set to "1000"
math(EXPR value "100 * 0xA" OUTPUT_FORMAT HEXADECIMAL)  # value is set to "0x3e8"