nodemcu-firmware/docs/modules/bit.md

bit Module

Since	Origin / Contributor	Maintainer	Source
2014-12-24	https://github.com/LuaDist/bitlib, Zeroday	Zeroday	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)