纯lua实现 utf-16le 和 utf-8互转

来源：互联网发布：linux 本地socket通信编辑：程序博客网时间：2024/04/29 00:01
原帖地址：http://www.cocoachina.com/bbs/read.php?tid-312194.html
做了一些小小的修改：
do    local bit = require("bit")    local resultStr={}    local function utf16le_to_utf8(convertStr)        if type(convertStr)~="string" then            return convertStr        end                local i=1        local len = 1;        while true do            local num1=string.byte(convertStr,i)            local unicode;            if num1 ~= nil then                local num2=string.byte(convertStr,i+1)                unicode = bit.bor(num1, bit.lshift(num2, 8));                i=i+2;            else                break;            end            -- print(unicode)                  if unicode <= 0x007f then                resultStr[len] = string.char(bit.band(unicode,0x7f))                len = len + 1;            elseif unicode >= 0x0080 and unicode <= 0x07ff then                                resultStr[len] = string.char(bit.bor(0xc0,bit.band(bit.rshift(unicode,6),0x1f)))                len = len + 1;                resultStr[len] = string.char(bit.bor(0x80,bit.band(unicode,0x3f)))                len = len + 1;            elseif unicode >= 0x0800 and unicode <= 0xffff then                resultStr[len] = string.char(bit.bor(0xe0,bit.band(bit.rshift(unicode,12),0x0f)))                len = len + 1;                resultStr[len] = string.char(bit.bor(0x80,bit.band(bit.rshift(unicode,6),0x3f)))                len = len + 1;                resultStr[len] = string.char(bit.bor(0x80,bit.band(unicode,0x3f)))                len = len + 1;            end                end                -- resultStr[len] = '\0'        -- print(resultStr)                return table.concat(resultStr, "", 1, len-1)            end    local function utf8_to_utf16le(convertStr)        if type(convertStr)~="string" then            return convertStr        end                local i=1        local len = 1;        local num1=string.byte(convertStr,i)                while num1~=nil do                    -- print(num1)                        local tempVar1,tempVar2                        if num1 >= 0x00 and num1 <= 0x7f then                tempVar1=num1                tempVar2=0            elseif bit.band(num1,0xe0)== 0xc0 then                local t1 = 0                local t2 = 0                                t1 = bit.band(num1,bit.rshift(0xff,3))                i=i+1                num1=string.byte(convertStr,i)                                t2 = bit.band(num1,bit.rshift(0xff,2))                                                tempVar1=bit.bor(t2,bit.lshift(bit.band(t1,bit.rshift(0xff,6)),6))                                tempVar2=bit.rshift(t1,2)            elseif bit.band(num1,0xf0)== 0xe0 then                local t1 = 0                local t2 = 0                local t3 = 0                                t1 = bit.band(num1,bit.rshift(0xff,3))                i=i+1                num1=string.byte(convertStr,i)                t2 = bit.band(num1,bit.rshift(0xff,2))                i=i+1                num1=string.byte(convertStr,i)                t3 = bit.band(num1,bit.rshift(0xff,2))                                tempVar1=bit.bor(bit.lshift(bit.band(t2,bit.rshift(0xff,6)),6),t3)                tempVar2=bit.bor(bit.lshift(t1,4),bit.rshift(t2,2))                        end                        resultStr[len] = string.char(tempVar1) .. string.char(tempVar2);            len = len + 1;            -- print(resultStr[len - 1])                        i=i+1            num1=string.byte(convertStr,i)        end                return table.concat(resultStr, "", 1, len - 1)    endend
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