我很难确定以下代码的作用。
我没有这方面的经验，我在每个变量上做了一个console.log（）来查看最新情况，但它看起来像是某种递归eval？谁能给我一些指示？
谢谢。
eval(function(r, e, a, l) {
var x = 0,
y = 0,
z = 0;
var t = [],
token = [];
while (1) {
if (x < 5) token.push(r.charAt(x));
else if (x < r.length) t.push(r.charAt(x));
x++;
if (y < 5) token.push(e.charAt(y));
else if (y < e.length) t.push(e.charAt(y));
y++;
if (z < 5) token.push(a.charAt(z));
else if (z < a.length) t.push(a.charAt(z));
z++;
if (r.length + e.length + a.length + l.length == t.length + token.length + l.length) break;
}
var d = t.join('');
var k = token.join('');
y = 0;
var bearer = [];
for (x = 0; x < t.length; x += 2) {
var c = -1;
if (k.charCodeAt(y) % 2) c = 1;
bearer.push(String.fromCharCode(parseInt(d.substr(x, 2), 32) - c));
y++;
if (y >= token.length) y = 0;
}
return bearer.join('');
}('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', '84a1843d3m3j3f3b123a300p1b1h3u1l311q1l361q1o3b1i3a1n1a3a3f3k1h39301p1s3i0a1n3f3f373f3i1j39301p1q1c373r1l341h393d322j3a1634373r1d38381h373f322j3a1o1s391k3g3d3m39123j371a3d3v3910363l1j3m37143j371a3a1a1j343l14363l10363j1d363j1u1b383c3a3f3d393f3d393h3c3n3v1l3e391a300c3e3f3g371a3s1n31303j2s3g1p1q1l343l1p1h3n3v1e1a1a3932363914141q323j3k393h383j323j331h3k2d153k3l1p181j121s1c353v3e3f363j1q1q363j013j3d3a181q181k1k1o3i1q1i1k3k1f3k1o3i123i1o3i181k1n1i1a1i1a3i1e3g1a1k1a3i1a3k123g1c1g1a3i181k183i183i1e3g1a3k1n3i183k1g3g1c1i1h3i183i183i1a3g1n3g1c3i1h3i183i1b3g1c1g1b3i181i1b3i183i1g3g1a3i163i1a3k1m3g1c1g1l3i183i1n3i181g1g3g1a3k173i1a3i1e3g1c3g123i161i113i183i153g1a3k1e3i183k1c3g1a3i1h3i181i183i181i1q3g1c3i1o3i183k1o3g1c1i1c3i163k113i1a3g183g1a3k1o3i1a1i1a3g1a3i133i161i123i183i1q3g1c3k1e3i183k1q3g1c1g133i163k113i181i1g3g1a1k1n3i1a1k1g3g1a1i133i181k1o3i183i1q3g1a1k1n3i183k1q3g1c1i153i163k1o3i1a3i1g3g1a1k1m3i181i153g1a3i1q3i183k1e3i183g1b1g1p3i1f1k163k133i193g1k3k113k1i3k1i1g183i1q1k1m1k1g1i1l3g1e1g1b1i101i103k1a1i1j3g1c3i133k153i1o1g1k3i1l3k151k1h3k1l1i1l3i123k131j103i1o3i143i143k103k1k3k1o3i1n3g1n3i1f3k1k3k1n3i1d1g171i1g3k1l3i1o3i151i1m3k1i3k1j3k1b3g1a1i191j131k1h3k193i1c3i1b3i1n3i1g3k131i193i1i1k141i1o1k183g1h3g1b3i1d1i133i1a3i1j3g1b1i171k173i193i193g1e1i173i1j1i1b1g1l1g1d3730133i173i103i1g3k1b1g1l3i173j1j1k1j3k1i3i133g1d3k1n3i183i1f3g1a3i1h3i1a1k173i1a3i183g1c1i1f3i163k1i3g1a1g1f3i1a3k1k3i1a3i1g3g1a1k113i161i1q3g1a3g153i183i1m3i1a1g1j3g1a1i1g3i181i133g1a1g1l3i1a3k1k3i183g1p3g1c3i183i183k1q3g1a1g1o3i1a3k1a3i1a3g123g1c3k103i161k1g3g1a3i1n3i183k1m3i1a3i1k3g1a3k113i161k173g183i1q3i1a1k183i183i1q3g1a1k123i161k1q3g1a3i1e3i183k1o3i1a1g173g1a3k103i181k1c3g183i133i181k1m3i183i1q3g1c1k1g3i163k1q3g1a1g1j3i181k1o3i181g1g3g1a1k1o3i181k1g3g181i133i181k103i183i1o3g1c1k1e3i163k1o3g181i1c3i183k1m3i181g1j3g1a3i131i1b1k1p1g133i1m3i171i1i3k1k1i1p1i1d1i1o3k191i1l1i131i191k1h3k1d3k1c3i1c1g1b1i133k1j1k1b3i1j3i123i1h1k133i1o1g1i3g1j3k1o3k1f1k1h3g1m3i1q3k1o3k1m3k1o3i1b3i151k131k1j3k1k3i1n3i1m3k101i151i193h193g173k121k1h3k151h1h3g1m1k153i1n3k1o1i1h1i171k133i1n3i1o3i153i1m3k151k1o3i1k1i193g1a1k143i173i1g3i1o3g1b3i193i1b3i1a3i193g1b1k1g3k1c3i173g1e3g1b3i1b121n1i1l3g133i1q3k131k1i3i1b1i1j3i193j193k1f1i1k1i1l1g191i183i183k1o3g1a1g1l3i1a3i1l3i1a1g1e3g1a3k193i181i1g3g1a3g123i181i1o3i1a3i133g1a3k1g3i163k1e3g183i1h3i1a1i163i1a3g1e3g1c3i1f3i183k1h3g1a1i1b3i1a3k163i1c1g1f3g1a3k1i3i181i1f3g1a3i1o3i1a3k1e3i1a3i1q3g1a1i113i181i153g183g1q3i1a1i113i1a3i1q3g1c1k1i3i163k133g181g1q3i183k1o3i1c1i1o3g1a1k1o3i181i153g181i1q3i1a1k1e3i1a3i1o3g1c1i173i163k133g1a3i183i183k1o3i1a3g1o3g1a3k113i161i1e3g183i133i183k183i1a3i1o3g1a1k123i161k133g183i123i183k1o3i1a1g123g1a3k1o3i181k173g183i1q3i183i1c3i1a3i1n1g1k1k1c3k111k1j3g173g1i3i1l3i113k1h3i153g1q1i1i3i1d3k1q3i191i1h3i1m3i1j3k171h1p1i1o3i1n3i1m3k1d3g1i1g183k1o1k1m1k1i1g1l3g1e1i191i101i1n3g1l3g1n3i1l3i111k143i1o3i1q3k1d1i141i1j3i153i123i1g1k1i3i1k3i1b3g1f3i103k1h1k1n1g1h3i1q3k191k1i3k171i1b3g1b1i121k143k1d3g1l3g1b3k1n3i1k3i1b3g133g1a3i1g3k1f3i1b3i1a3g153i1a1i1h3i1b3i1a1g1m1i1a3k173i1c3i1p1b1m17131j1k141415161j141q12181q', 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'95f6fd7de7271537c80cb8f29e67434c35952ca4'));