php 可能的字符 base64 url 安全功能
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possible characters base64 url safe function
提问by Chris Muench
What is the range of possible characters returned from this string?
从这个字符串返回的可能字符的范围是多少？
function base64url_encode($data)
{
return rtrim(strtr(base64_encode($data), '+/', '-_'), '=');
}
My guess is [a-z0-9-_]
我的猜测是 [a-z0-9-_]
回答by Floern
Base64 encoded strings may contain the characters a-z A-Z 0-9 + / =.
Base64 编码的字符串可能包含字符a-z A-Z 0-9 + / =。
You're removing the right-padding =and replacing +with -and /with _.
您要移除右填充=和更换+用-和/用_。
So in your case, yes, the possible characters are a-z A-Z 0-9 - _
所以在你的情况下，是的，可能的字符是 a-z A-Z 0-9 - _
回答by salathe
The range of possible characters returned are:
可能返回的字符范围是：
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Za, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z0, 1, 2, 3, 4, 5, 6, 7, 8, 9-(minus) and_(underscore)
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Za, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z0, 1, 2, 3, 4, 5, 6, 7, 8, 9-（减号）和_（下划线）
In your regex-style, that would be [a-zA-Z0-9_-].
在您的正则表达式风格中，这将是[a-zA-Z0-9_-].
