51dc35cf23
This patch implements an Ellipsis utility to append an ellipsis (...) when truncating strings in output. It also fixes the existing Truncate() utility to be compatible with unicode/multibyte characters. Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
101 lines
2.4 KiB
Go
101 lines
2.4 KiB
Go
// Package stringutils provides helper functions for dealing with strings.
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package stringutils
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import (
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"bytes"
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"math/rand"
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"strings"
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"github.com/docker/docker/pkg/random"
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)
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// GenerateRandomAlphaOnlyString generates an alphabetical random string with length n.
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func GenerateRandomAlphaOnlyString(n int) string {
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// make a really long string
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letters := []byte("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
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b := make([]byte, n)
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for i := range b {
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b[i] = letters[random.Rand.Intn(len(letters))]
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}
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return string(b)
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}
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// GenerateRandomASCIIString generates an ASCII random string with length n.
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func GenerateRandomASCIIString(n int) string {
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chars := "abcdefghijklmnopqrstuvwxyz" +
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"ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
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"~!@#$%^&*()-_+={}[]\\|<,>.?/\"';:` "
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res := make([]byte, n)
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for i := 0; i < n; i++ {
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res[i] = chars[rand.Intn(len(chars))]
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}
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return string(res)
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}
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// Ellipsis truncates a string to fit within maxlen, and appends ellipsis (...).
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// For maxlen of 3 and lower, no ellipsis is appended.
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func Ellipsis(s string, maxlen int) string {
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r := []rune(s)
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if len(r) <= maxlen {
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return s
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}
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if maxlen <= 3 {
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return string(r[:maxlen])
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}
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return string(r[:maxlen-3]) + "..."
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}
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// Truncate truncates a string to maxlen.
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func Truncate(s string, maxlen int) string {
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r := []rune(s)
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if len(r) <= maxlen {
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return s
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}
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return string(r[:maxlen])
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}
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// InSlice tests whether a string is contained in a slice of strings or not.
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// Comparison is case insensitive
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func InSlice(slice []string, s string) bool {
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for _, ss := range slice {
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if strings.ToLower(s) == strings.ToLower(ss) {
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return true
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}
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}
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return false
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}
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func quote(word string, buf *bytes.Buffer) {
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// Bail out early for "simple" strings
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if word != "" && !strings.ContainsAny(word, "\\'\"`${[|&;<>()~*?! \t\n") {
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buf.WriteString(word)
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return
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}
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buf.WriteString("'")
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for i := 0; i < len(word); i++ {
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b := word[i]
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if b == '\'' {
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// Replace literal ' with a close ', a \', and a open '
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buf.WriteString("'\\''")
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} else {
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buf.WriteByte(b)
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}
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}
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buf.WriteString("'")
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}
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// ShellQuoteArguments takes a list of strings and escapes them so they will be
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// handled right when passed as arguments to a program via a shell
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func ShellQuoteArguments(args []string) string {
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var buf bytes.Buffer
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for i, arg := range args {
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if i != 0 {
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buf.WriteByte(' ')
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}
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quote(arg, &buf)
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}
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return buf.String()
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}
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