javascript - Converting text to hexadecimal on mac -

i trying convert text hexadecimal characters in order build dmg on mac.
i'm getting burned fact hexadecimals not seem refer same characters on mac , windows ascii characters > 127. , seems basic javascript functions give "windows" translation.
need "mac" translation hexadecimal...

i'm doing far:

const filedata = await parsejson(readfile(item.file, "utf-8")) const buttonsstr = labeltohex(filedata.lang)  function labeltohex(label: string) {   return hexencode(label).tostring().touppercase() }  function hexencode(str: string) {   let   let result = ""    (i = 0; < str.length; i++) {     result += unicodetohex(str.charcodeat(i))   }    return result }  function unicodetohex(unicode: number) {   const hex = unicode.tostring(16)   return ("0" + hex).slice(-2) } 

if pass in: français éàè
i get: 46 72 61 6e e7 61 69 73 e9 e0 e8
but when read back, get: franÀais ȇË
i'm expecting get: 46 72 61 6e 8d 61 69 73 8e 88 8f
so reading gives: 46 72 61 6e e7 61 69 73 e9 e0 e8

this corresponds sheets:
https://academic.evergreen.edu/projects/biophysics/technotes/program/ascii_ext-mac.htm https://academic.evergreen.edu/projects/biophysics/technotes/program/ascii_ext-pc.htm

nonetheless, not able find either npm package translate hex based on os or obscure js function still haven't stumbled upon?
i'm running out of ideas , do:

function unicodetohex(unicode: number) {   if (unicode < 128) {     const hex = unicode.tostring(16)     return ("0" + hex).slice(-2)   }    if (unicode === 233) { return "8e" }//é   if (unicode === 224) { return "88" }//à   if (unicode === 232) { return "8f" }//è    return "3f" //? } 

but avoid that...

i've found way it, code pages, stated @keith

const cptable = require("codepage") function hexencode(str: string, lang: string, langwithregion: string) {   let code   let hex   let   const maccodepages = getmaccodepage(lang, langwithregion)   let result = ""    (i = 0; < str.length; i++) {     try {       code = getmaccharcode(str, i, maccodepages)       if (code === undefined) {         hex = "3f" //?       } else {         hex = code.tostring(16)       }        result += hex     } catch (e) {       debug("there problem while trying convert char hex: " + e)       result += "3f" //?     }   }    return result }  function getmaccodepage(lang: string, langwithregion: string) {   switch (lang) {     case "ja": //japanese       return [10001] //apple japanese     case "zh": //chinese       if (langwithregion === "zh_cn") {         return [10008] //apple simplified chinese (gb 2312)       }       return [10002] //apple traditional chinese (big5)     case "ko": //korean       return [10003] //apple korean     case "ar": //arabic     case "ur": //urdu       return [10004] //apple arabic     case "he": //hebrew       return [10005] //apple hebrew     case "el": //greek     case "elc": //greek       return [10006] //apple greek     case "ru": //russian     case "be": //belarussian     case "sr": //serbian     case "bg": //bulgarian     case "uz": //uzbek       return [10007] //apple macintosh cyrillic     case "ro": //romanian       return [10010] //apple romanian     case "uk": //ukrainian       return [10017] //apple ukrainian     case "th": //thai       return [10021] //apple thai     case "et": //estonian     case "lt": //lithuanian     case "lv": //latvian     case "pl": //polish     case "hu": //hungarian     case "cs": //czech     case "sk": //slovak       return [10029] //apple macintosh central europe     case "is": //icelandic     case "fo": //faroese       return [10079] //apple icelandic     case "tr": //turkish       return [10081] //apple turkish     case "hr": //croatian     case "sl": //slovenian       return [10082] //apple croatian     default:       return [10000] //apple macintosh roman   } }  function getmaccharcode(str: string, i: number, maccodepages: any) {   let code = str.charcodeat(i)   let j   if (code < 128) {     code = str.charcodeat(i)   }   else if (code < 256) {     //codepage 10000 = mac os roman     code = cptable[10000].enc[str[i]]   }   else {     (j = 0; j < maccodepages.length; j++) {       code = cptable[maccodepages[j]].enc[str[i]]       if (code !== undefined) {         break       }     }   }    return code }