tailscale/util/strs/strs.go
Brad Fitzpatrick 01e8ef7293 util/strs: add new package for string utility funcs
Updates #5309

Change-Id: I677cc6e01050b6e10d8d6907d961b11c7a787a05
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2022-08-05 15:06:08 -07:00

37 lines
1.2 KiB
Go

// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package strs contains string-related utility funcs.
package strs
import "strings"
// CutPrefix returns s without the provided leading prefix string
// and reports whether it found the prefix.
// If s doesn't start with prefix, CutPrefix returns s, false.
// If prefix is the empty string, CutPrefix returns s, true.
//
// TODO: remove this once Go 1.20 is out with it.
// See https://github.com/tailscale/tailscale/issues/5309
func CutPrefix(s, prefix string) (after string, found bool) {
if !strings.HasPrefix(s, prefix) {
return s, false
}
return s[len(prefix):], true
}
// CutSuffix returns s without the provided ending suffix string
// and reports whether it found the suffix.
// If s doesn't end with suffix, CutSuffix returns s, false.
// If suffix is the empty string, CutSuffix returns s, true.
//
// See https://github.com/tailscale/tailscale/issues/5309
// TODO: remove this once Go 1.20 is out with it.
func CutSuffix(s, suffix string) (before string, found bool) {
if !strings.HasSuffix(s, suffix) {
return s, false
}
return s[:len(s)-len(suffix)], true
}