blob: bfe1f209584e26cb77391a0bb6d26b7d76157318 [file] [log] [blame]
// Copyright 2020 The Go 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 main
import (
"path/filepath"
"strings"
)
// hasPathPrefix reports whether the slash-separated path s
// begins with the elements in prefix.
// Copied from cmd/go/internal/str.HasPathPrefix.
func hasPathPrefix(s, prefix string) bool {
if len(s) == len(prefix) {
return s == prefix
}
if prefix == "" {
return true
}
if len(s) > len(prefix) {
if prefix[len(prefix)-1] == '/' || s[len(prefix)] == '/' {
return s[:len(prefix)] == prefix
}
}
return false
}
// hasFilePathPrefix reports whether the filesystem path s
// begins with the elements in prefix.
// Copied from cmd/go/internal/str.HasFilePathPrefix.
func hasFilePathPrefix(s, prefix string) bool {
sv := strings.ToUpper(filepath.VolumeName(s))
pv := strings.ToUpper(filepath.VolumeName(prefix))
s = s[len(sv):]
prefix = prefix[len(pv):]
switch {
default:
return false
case pv != "" && sv != pv:
return false
case len(s) == len(prefix):
return s == prefix
case prefix == "":
return true
case len(s) > len(prefix):
if prefix[len(prefix)-1] == filepath.Separator {
return strings.HasPrefix(s, prefix)
}
return s[len(prefix)] == filepath.Separator && s[:len(prefix)] == prefix
}
}
// trimFilePathPrefix returns the given filesystem path s without the leading
// prefix.
func trimFilePathPrefix(s, prefix string) string {
sv := strings.ToUpper(filepath.VolumeName(s))
pv := strings.ToUpper(filepath.VolumeName(prefix))
s = s[len(sv):]
prefix = prefix[len(pv):]
if !hasFilePathPrefix(s, prefix) || len(prefix) == 0 {
return s
}
if len(s) == len(prefix) {
return ""
}
if prefix[len(prefix)-1] == filepath.Separator {
return strings.TrimPrefix(s, prefix)
}
return s[len(prefix)+1:]
}
// trimPathPrefix returns p without the leading prefix. Unlike
// strings.TrimPrefix, the prefix will only match on slash-separted component
// boundaries, so trimPathPrefix("aa/b", "aa") returns "b", but
// trimPathPrefix("aa/b", "a") returns "aa/b".
func trimPathPrefix(p, prefix string) string {
if prefix == "" {
return p
}
if prefix == p {
return ""
}
return strings.TrimPrefix(p, prefix+"/")
}