mirror of https://github.com/gogs/gogs.git
47 lines
1.0 KiB
Go
47 lines
1.0 KiB
Go
// Copyright 2020 The Gogs Authors. All rights reserved.
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// Use of this source code is governed by a MIT-style
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// license that can be found in the LICENSE file.
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package strutil
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import (
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"crypto/rand"
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"math/big"
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"unicode"
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)
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// ToUpperFirst returns s with only the first Unicode letter mapped to its upper case.
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func ToUpperFirst(s string) string {
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for i, v := range s {
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return string(unicode.ToUpper(v)) + s[i+1:]
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}
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return ""
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}
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// RandomChars returns a generated string in given number of random characters.
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func RandomChars(n int) (string, error) {
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const alphanum = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
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randomInt := func(max *big.Int) (int, error) {
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r, err := rand.Int(rand.Reader, max)
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if err != nil {
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return 0, err
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}
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return int(r.Int64()), nil
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}
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buffer := make([]byte, n)
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max := big.NewInt(int64(len(alphanum)))
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for i := 0; i < n; i++ {
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index, err := randomInt(max)
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if err != nil {
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return "", err
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}
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buffer[i] = alphanum[index]
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}
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return string(buffer), nil
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}
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