blob: 0c8aaeaca1fba0f5f2cbc0d27c2262d8d43932f5 [file] [log] [blame]
// Copyright 2018 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 str
import (
"path/filepath"
"strings"
)
// HasPathPrefix reports whether the slash-separated path s
// begins with the elements in prefix.
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.
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 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 s without the leading path elements in prefix.
// If s does not start with prefix (HasFilePathPrefix with the same arguments
// returns false), TrimFilePathPrefix returns s. If s equals prefix,
// TrimFilePathPrefix returns "".
func TrimFilePathPrefix(s, prefix string) string {
if !HasFilePathPrefix(s, prefix) {
return s
}
if len(s) == len(prefix) {
return ""
}
return s[len(prefix)+1:]
}