假设您可以使用String.fromCharCode
,您可以重新构建String以包含零字节(即,将String用于二进制数据),然后将其编码为Base64。
var cmd = 'New-Item -Path "C:\\" -Name "Test" -ItemType Directory',
ar = new Array(cmd.length * 2),
i, j, s, b64;
// build array of bytes
for (i = 0, j = 0; i < cmd.length; j = 2 * ++i)
ar[j] = cmd.charCodeAt(i);
// build string from array
s = String.fromCharCode.apply(String, ar);
// to base64
b64 = btoa(s);
此方法避免需要Blob、FileReader或异步方法。
刚刚写了一个库,用于在base64、base16、base8和base6之间转换二进制数据,以及在它们之间转换utf8和utf16 。这些函数都适用于Array、ArrayBuffer和Uint?Array ,但使用String的Conv86.utfX.toY
函数除外。
var Conv86 = (function () {
var chars = (
'ABCDEFGHIJKLMNOPQRSTUVWXYZ' +
'abcdefghijklmnopqrstuvwxyz' +
'0123456789+/'
),
inver = {}, i;
for (i = 0; i < chars.length; ++i) {
inver[chars[i]] = i;
}
function base8To6(arr8) {
var arr6 = [], i,
e1, e2, e3,
s1, s2, s3, s4,
d1, d2, d3;
for (i = 0; i < arr8.length; i += 3) {
e1 = (d1 = arr8[i] ) & 255;
e2 = (d2 = arr8[i + 1]) & 255;
e3 = (d3 = arr8[i + 2]) & 255;
// wwwwwwxx xxxxyyyy yyzzzzzz
s1 = e1 >>> 2 ;
s2 = ((e1 & 3) << 4) + (e2 >>> 4);
s3 = ((e2 & 15) << 2) + (e3 >>> 6);
s4 = e3 & 63 ;
arr6.push(s1, s2);
if (d3 !== undefined)
arr6.push(s3, s4);
else if (d2 !== undefined)
arr6.push(s3);
}
arr6.byteLength = arr8.length;
return arr6;
}
function base6To8(arr6) {
var arr8 = [], i,
e1, e2, e3,
s1, s2, s3, s4,
d1, d2, d3, d4;
for (i = 0; i < arr6.length; i += 4) {
s1 = (d1 = arr6[i] ) & 63;
s2 = (d2 = arr6[i + 1]) & 63;
s3 = (d3 = arr6[i + 2]) & 63;
s4 = (d4 = arr6[i + 3]) & 63;
// xxxxxx xxyyyy yyyyzz zzzzzz
e1 = ( s1 << 2) + (s2 >>> 4);
e2 = ((s2 & 15) << 4) + (s3 >>> 2);
e3 = ((s3 & 3) << 6) + s4 ;
arr8.push(e1);
if (d3 !== undefined)
arr8.push(e2, e3);
else if (d2 !== undefined )
arr8.push(e2);
}
if (arr6.byteLength !== undefined)
arr8.length = +arr6.byteLength;
return arr8;
}
function base6To64(arr6) {
var i, b64 = '';
for (i = 0; i < arr6.length; ++i) b64 += chars.charAt(arr6[i]);
/*if (arr6.bytesLength) {
i = arr6.bytesLength % 3;
if (i) ++i;
} else */
i = b64.length % 4;
b64 += ['', '==', '==', '='][i];
return b64;
}
function base8To64(arr8) {
return base6To64(base8To6(arr8));
}
function base64To6(b64) {
var arr6 = [],
i = b64.length, lenMod = 0;
while (b64.charAt(--i) === '=')
++lenMod;
for (i = 0; i < b64.length - lenMod; ++i)
arr6.push(inver[b64.charAt(i)]);
i = b64.length & 3;
if (i) i = 4 - i;
i = i + b64.length;
arr6.byteLength = 3 * i / 4 - lenMod;
return arr6;
}
function base64To8(b64) {
return base6To8(base64To6(b64));
}
// base16
function base8To16(arr8) {
var i, arr16 = [];
for (i = 0; i < arr8.length; i = i + 2)
arr16.push((arr8[i] << 8) + arr8[i + 1]);
return arr16;
}
function base16To8(arr16) {
var i, arr8 = [];
for (i = 0; i < arr16.length; ++i)
arr8.push(arr16[i] >>> 8, arr16[i] & 255);
return arr8;
}
function base6To16(arr6) {
return base8To16(base6To8(arr6));
}
function base16To6(arr16) {
return base8To6(base16To8(arr16));
}
function base16To64(arr16) {
return base8To64(base16To8(arr16));
}
function base64To16(b64) {
return base8To16(base64To8(b64));
}
// from UTF8 to X
function utf8To8(str) {
var arr8 = [], i;
for (i = 0; i < str.length; ++i)
arr8.push(str.charCodeAt(i) & 255);
return arr8;
}
function utf8To6(str) {
return base8To6(utf8To8(str));
}
function utf8To16(str) {
return base8To16(utf8To8(str));
}
function utf8To64(str) {
return base8To64(utf8To8(str));
}
// from X to UTF8
function utf8From8(arr8) {
var utf8arr = [];
for (i = 0; i < arr8.length; ++i)
utf8arr.push(arr8[i]);
return String.fromCharCode.apply(String, utf8arr);
}
function utf8From6(arr6) {
return utf8From8(base6To8(arr6));
}
function utf8From16(arr16) {
return utf8From8(base16To8(arr16));
}
function utf8From64(b64) {
return utf8From8(base64To8(b64));
}
// from UTF16 to X
function utf16To16(str) {
var arr16 = [], i, c;
for (i = 0; i < str.length; ++i) {
c = str.charCodeAt(i) & 65535;
arr16.push(((c & 255) << 8) + (c >>> 8));
}
return arr16;
}
function utf16To8(str) {
return base16To8(utf16To16(str));
}
function utf16To6(str) {
return base16To6(utf16To16(str));
}
function utf16To64(str) {
return base16To64(utf16To16(str));
}
// from X to UTF16
function utf16From16(arr16) {
var utf16arr = [];
for (i = 0; i < arr16.length; ++i)
utf16arr.push(((arr16[i] & 255) << 8) + (arr16[i] >>> 8));
return String.fromCharCode.apply(String, utf16arr);
}
function utf16From8(arr8) {
return utf16From16(base8To16(arr8));
}
function utf16From6(arr6) {
return utf16From16(base6To16(arr6));
}
function utf16From64(b64) {
return utf16From16(base64To16(b64));
}
return {
base6: {
to8: base6To8,
to16: base6To16,
to64: base6To64,
},
base8: {
to6: base8To6,
to16: base8To16,
to64: base8To64
},
base16: {
to6: base16To6,
to8: base16To8,
to64: base16To64
},
base64: {
to6: base64To6,
to8: base64To8,
to16: base64To16
},
utf8: {
to8: utf8To8,
to6: utf8To6,
to16: utf8To16,
to64: utf8To64,
from8: utf8From8,
from6: utf8From6,
from16: utf8From16,
from64: utf8From64
},
utf16: {
to8: utf16To8,
to6: utf16To6,
to16: utf16To16,
to64: utf16To64,
from8: utf16From8,
from6: utf16From6,
from16: utf16From16,
from64: utf16From64
}
};
}());
示例用法
Conv86.utf16.from64(
Conv86.utf16.to64('New-Item -Path "C:\\" -Name "Test" -ItemType Directory')
// "TgBlAHcALQBJAHQAZQBtACAALQBQAGEAdABoACAAIgBDADoAXAAiACAALQBOAGEAbQBlACAAIgBUAGUAcwB0ACIAIAAtAEkAdABlAG0AVAB5AHAAZQAgAEQAaQByAGUAYwB0AG8AcgB5AA=="
); // "New-Item -Path "C:\" -Name "Test" -ItemType Directory"