BitArShift

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This functions performs an arithmetic shift on the integer value by integer n positions. In an arithmetic shift, zeros are shifted in to replace the discarded bits. In a right arithmetic shift, the sign bit is shifted in on the left, thus preserving the sign of the operand. See Bitwise operation for more details.

Syntax

int bitArShift ( int value, int n )

Required arguments

  • value: The value you want to perform the arithmetic shift on.
  • n: The amount of positions to shift the value by.

Returns

Returns the arithmetic shifted value as integer.

Example

Click to collapse [-]
Client

This example adds the clientside command /arshift [value] [positions = 1], which will print the result from the function bitArShift.

function getNumberAsBitString(value)
    if type(value) ~= 'number' then
        return false
    else
        local binary = ''

        for field = 31, 0, -1 do
            binary = binary .. bitExtract(value, field)

            if field % 4 == 0 then
                binary = binary ..' '
            end
        end

        return binary
    end
end

addCommandHandler('arshift',
    function (command, value, positions)
        if type(value) ~= 'string' or value:len() == 0 then
            return outputChatBox('* Syntax: /arshift [value] [positions = 1]')
        end

        if type(positions) ~= 'string' or positions:len() == 0 then
            positions = 1
        end

        local result = bitArShift(tonumber(value), tonumber(positions))
        local binary = getNumberAsBitString(result)

        outputChatBox('* Decimal: '.. result ..', Binary: '.. binary)
    end
)

If you trigger the command with /arshift 0xF0 4 and /arshift 0xF0 -4 you will receive as response:

* Decimal: 15,   Binary: 0000 0000 0000 0000 0000 0000 0000 1111
* Decimal: 3840, Binary: 0000 0000 0000 0000 0000 1111 0000 0000

See Also