nodemcu-firmware/docs/en/modules/bit.md

# bit Module
| Since  | Origin / Contributor  | Maintainer  | Source  |
| :----- | :-------------------- | :---------- | :------ |
| 2014-12-24 | [https://github.com/LuaDist/bitlib](https://github.com/LuaDist/bitlib), [Zeroday](https://github.com/funshine) | [Zeroday](https://github.com/funshine) | [bit.c](../../../app/modules/bit.c)|


Bit manipulation support, on 32bit integers.

## bit.arshift()
Arithmetic right shift a number equivalent to `value >> shift` in C.

####Syntax
`bit.arshift(value, shift)`

####Parameters
- `value` the value to shift
- `shift` positions to shift

####Returns
the number shifted right (arithmetically)

## bit.band()

Bitwise AND, equivalent to `val1 & val2 & ... & valn` in C.

####Syntax
`bit.band(val1, val2 [, ... valn])`

####Parameters
 - `val1` first AND argument
 - `val2` second AND argument
 - `...valn` ...nth AND argument

####Returns
the bitwise AND of all the arguments (number)

## bit.bit()

Generate a number with a 1 bit (used for mask generation). Equivalent to `1 << position` in C.

####Syntax
`bit.bit(position)`

####Parameters
`position` position of the bit that will be set to 1

####Returns
a number with only one 1 bit at position (the rest are set to 0)

## bit.bnot()

Bitwise negation, equivalent to `~value in C.

####Syntax
`bit.bnot(value)`

####Parameters
`value` the number to negate

####Returns
the bitwise negated value of the number

## bit.bor()
Bitwise OR, equivalent to `val1 | val2 | ... | valn` in C.

####Syntax
`bit.bor(val1, val2 [, ... valn])`

####Parameters
- `val1` first OR argument.
- `val2` second OR argument.
- `...valn` ...nth OR argument

####Returns
the bitwise OR of all the arguments (number)

## bit.bxor()

Bitwise XOR, equivalent to `val1 ^ val2 ^ ... ^ valn` in C.

####Syntax
`bit.bxor(val1, val2 [, ... valn])`

####Parameters
- `val1` first XOR argument
- `val2` second XOR argument
- `...valn` ...nth XOR argument

####Returns
the bitwise XOR of all the arguments (number)

## bit.clear()
Clear bits in a number.

####Syntax
`bit.clear(value, pos1 [, ... posn])`

####Parameters
- `value` the base number
- `pos1` position of the first bit to clear
- `...posn` position of thet nth bit to clear

####Returns
the number with the bit(s) cleared in the given position(s)

## bit.isclear()

Test if a given bit is cleared.

####Syntax
`bit.isclear(value, position)`

####Parameters
- `value` the value to test
- `position` bit position to test

####Returns
true if the bit at the given position is 0, false othewise

## bit.isset()

Test if a given bit is set.

####Syntax
`bit.isset(value, position)`

####Parameters
- `value` the value to test
- `position` bit position to test

####Returns
true if the bit at the given position is 1, false otherwise

## bit.lshift()
Left-shift a number, equivalent to `value << shift` in C.

####Syntax
`bit.lshift(value, shift)`

####Parameters
- `value` the value to shift
- `shift` positions to shift

####Returns
the number shifted left

## bit.rshift()

Logical right shift a number, equivalent to `( unsigned )value >> shift` in C.

####Syntax
`bit.rshift(value, shift)`

####Parameters
- `value` the value to shift.
- `shift` positions to shift.

####Returns
the number shifted right (logically)

## bit.set()

Set bits in a number.

####Syntax
`bit.set(value, pos1 [, ... posn ])`

####Parameters
- `value` the base number.
- `pos1` position of the first bit to set.
- `...posn` position of the nth bit to set.

####Returns
the number with the bit(s) set in the given position(s)