| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 files |
| |
| import ( |
| "os" |
| "os/exec" |
| "path/filepath" |
| ) |
| |
| import ( |
| "github.com/pkg/errors" |
| ) |
| |
| type LookupPathFn = func() (string, error) |
| |
| // LookupNextToCurrentExecutable looks for the binary next to the current binary |
| // Example: if this function is executed by /usr/bin/dubbo-dp, this function will lookup for binary 'x' in /usr/bin/x |
| func LookupNextToCurrentExecutable(binary string) LookupPathFn { |
| return func() (string, error) { |
| ex, err := os.Executable() |
| if err != nil { |
| return "", err |
| } |
| return filepath.Dir(ex) + "/" + binary, nil |
| } |
| } |
| |
| // LookupInCurrentDirectory looks for the binary in the current directory |
| // Example: if this function is executed by /usr/bin/dubbo-dp that was run in /home/dubbo-dp, this function will lookup for binary 'x' in /home/dubbo-dp/x |
| func LookupInCurrentDirectory(binary string) LookupPathFn { |
| return func() (string, error) { |
| cwd, err := os.Getwd() |
| if err != nil { |
| return "", err |
| } |
| return cwd + "/" + binary, nil |
| } |
| } |
| |
| func LookupInPath(path string) LookupPathFn { |
| return func() (string, error) { |
| return path, nil |
| } |
| } |
| |
| // LookupBinaryPath looks for a binary in order of passed lookup functions. |
| // It fails only if all lookup function does not contain a binary. |
| func LookupBinaryPath(pathFns ...LookupPathFn) (string, error) { |
| var candidatePaths []string |
| for _, candidatePathFn := range pathFns { |
| candidatePath, err := candidatePathFn() |
| if err != nil { |
| continue |
| } |
| candidatePaths = append(candidatePaths, candidatePath) |
| path, err := exec.LookPath(candidatePath) |
| if err == nil { |
| return path, nil |
| } |
| } |
| |
| return "", errors.Errorf("could not find executable binary in any of the following paths: %v", candidatePaths) |
| } |