| // Copyright 2017 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 base |
| |
| import ( |
| "os" |
| "path/filepath" |
| "runtime" |
| "strings" |
| "sync" |
| ) |
| |
| var cwd string |
| var cwdOnce sync.Once |
| |
| // UncachedCwd returns the current working directory. |
| // Most callers should use Cwd, which caches the result for future use. |
| // UncachedCwd is appropriate to call early in program startup before flag parsing, |
| // because the -C flag may change the current directory. |
| func UncachedCwd() string { |
| wd, err := os.Getwd() |
| if err != nil { |
| Fatalf("cannot determine current directory: %v", err) |
| } |
| return wd |
| } |
| |
| // Cwd returns the current working directory at the time of the first call. |
| func Cwd() string { |
| cwdOnce.Do(func() { |
| cwd = UncachedCwd() |
| }) |
| return cwd |
| } |
| |
| // ShortPath returns an absolute or relative name for path, whatever is shorter. |
| func ShortPath(path string) string { |
| if rel, err := filepath.Rel(Cwd(), path); err == nil && len(rel) < len(path) { |
| return rel |
| } |
| return path |
| } |
| |
| // RelPaths returns a copy of paths with absolute paths |
| // made relative to the current directory if they would be shorter. |
| func RelPaths(paths []string) []string { |
| var out []string |
| for _, p := range paths { |
| rel, err := filepath.Rel(Cwd(), p) |
| if err == nil && len(rel) < len(p) { |
| p = rel |
| } |
| out = append(out, p) |
| } |
| return out |
| } |
| |
| // IsTestFile reports whether the source file is a set of tests and should therefore |
| // be excluded from coverage analysis. |
| func IsTestFile(file string) bool { |
| // We don't cover tests, only the code they test. |
| return strings.HasSuffix(file, "_test.go") |
| } |
| |
| // IsNull reports whether the path is a common name for the null device. |
| // It returns true for /dev/null on Unix, or NUL (case-insensitive) on Windows. |
| func IsNull(path string) bool { |
| if path == os.DevNull { |
| return true |
| } |
| if runtime.GOOS == "windows" { |
| if strings.EqualFold(path, "NUL") { |
| return true |
| } |
| } |
| return false |
| } |