blob: 91615bf5c825e3d8d8a3e92e9a5feaae76f2edb1 [file] [log] [blame]
// Copyright 2017 The LUCI Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package prober
import (
"os"
"path/filepath"
"strings"
"go.chromium.org/luci/common/errors"
"go.chromium.org/luci/common/system/environ"
)
func chkStat(file string) error {
d, err := os.Stat(file)
if err != nil {
return err
}
if d.IsDir() {
return os.ErrPermission
}
return nil
}
func hasExt(file string) bool {
i := strings.LastIndex(file, ".")
if i < 0 {
return false
}
return strings.LastIndexAny(file, `:\/`) < i
}
func findExecutable(file string, exts []string) (string, error) {
if len(exts) == 0 {
return file, chkStat(file)
}
if hasExt(file) {
if chkStat(file) == nil {
return file, nil
}
}
for _, e := range exts {
if f := file + e; chkStat(f) == nil {
return f, nil
}
}
return "", os.ErrNotExist
}
// findInDir is a paraphrased and trimmed version of "exec.LookPath"
// (for Windows),
//
// Copied from:
// https://github.com/golang/go/blob/d234f9a75413fdae7643e4be9471b4aeccf02478/src/os/exec/lp_windows.go
//
// Modified to:
// - Use a supplied "dir" instead of scanning through PATH.
// - Not consider cases where "file" is an absolute path
// - Ignore the possibility that "file" may be in the CWD; only look in "dir".
func findInDir(file, dir string, env environ.Env) (string, error) {
var exts []string
if x, ok := env.Lookup(`PATHEXT`); ok {
for _, e := range strings.Split(strings.ToLower(x), `;`) {
if e == "" {
continue
}
if e[0] != '.' {
e = "." + e
}
exts = append(exts, e)
}
} else {
exts = []string{".com", ".exe", ".bat", ".cmd"}
}
if f, err := findExecutable(filepath.Join(dir, file), exts); err == nil {
return f, nil
}
return "", errors.New("not found")
}