| // Copyright 2022 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 exec_test |
| |
| import ( |
| "errors" |
| "internal/testenv" |
| "os" |
| . "os/exec" |
| "path/filepath" |
| "runtime" |
| "strings" |
| "testing" |
| ) |
| |
| var pathVar string = func() string { |
| if runtime.GOOS == "plan9" { |
| return "path" |
| } |
| return "PATH" |
| }() |
| |
| func TestLookPath(t *testing.T) { |
| testenv.MustHaveExec(t) |
| // Not parallel: uses os.Chdir and t.Setenv. |
| |
| tmpDir := filepath.Join(t.TempDir(), "testdir") |
| if err := os.Mkdir(tmpDir, 0777); err != nil { |
| t.Fatal(err) |
| } |
| |
| executable := "execabs-test" |
| if runtime.GOOS == "windows" { |
| executable += ".exe" |
| } |
| if err := os.WriteFile(filepath.Join(tmpDir, executable), []byte{1, 2, 3}, 0777); err != nil { |
| t.Fatal(err) |
| } |
| cwd, err := os.Getwd() |
| if err != nil { |
| t.Fatal(err) |
| } |
| defer func() { |
| if err := os.Chdir(cwd); err != nil { |
| panic(err) |
| } |
| }() |
| if err = os.Chdir(tmpDir); err != nil { |
| t.Fatal(err) |
| } |
| t.Setenv("PWD", tmpDir) |
| t.Logf(". is %#q", tmpDir) |
| |
| origPath := os.Getenv(pathVar) |
| |
| // Add "." to PATH so that exec.LookPath looks in the current directory on all systems. |
| // And try to trick it with "../testdir" too. |
| for _, errdot := range []string{"1", "0"} { |
| t.Run("GODEBUG=execerrdot="+errdot, func(t *testing.T) { |
| t.Setenv("GODEBUG", "execerrdot="+errdot+",execwait=2") |
| for _, dir := range []string{".", "../testdir"} { |
| t.Run(pathVar+"="+dir, func(t *testing.T) { |
| t.Setenv(pathVar, dir+string(filepath.ListSeparator)+origPath) |
| good := dir + "/execabs-test" |
| if found, err := LookPath(good); err != nil || !strings.HasPrefix(found, good) { |
| t.Fatalf(`LookPath(%#q) = %#q, %v, want "%s...", nil`, good, found, err, good) |
| } |
| if runtime.GOOS == "windows" { |
| good = dir + `\execabs-test` |
| if found, err := LookPath(good); err != nil || !strings.HasPrefix(found, good) { |
| t.Fatalf(`LookPath(%#q) = %#q, %v, want "%s...", nil`, good, found, err, good) |
| } |
| } |
| |
| _, err := LookPath("execabs-test") |
| if errdot == "1" { |
| if err == nil { |
| t.Fatalf("LookPath didn't fail when finding a non-relative path") |
| } else if !errors.Is(err, ErrDot) { |
| t.Fatalf("LookPath returned unexpected error: want Is ErrDot, got %q", err) |
| } |
| } else { |
| if err != nil { |
| t.Fatalf("LookPath failed unexpectedly: %v", err) |
| } |
| } |
| |
| cmd := Command("execabs-test") |
| if errdot == "1" { |
| if cmd.Err == nil { |
| t.Fatalf("Command didn't fail when finding a non-relative path") |
| } else if !errors.Is(cmd.Err, ErrDot) { |
| t.Fatalf("Command returned unexpected error: want Is ErrDot, got %q", cmd.Err) |
| } |
| cmd.Err = nil |
| } else { |
| if cmd.Err != nil { |
| t.Fatalf("Command failed unexpectedly: %v", err) |
| } |
| } |
| |
| // Clearing cmd.Err should let the execution proceed, |
| // and it should fail because it's not a valid binary. |
| if err := cmd.Run(); err == nil { |
| t.Fatalf("Run did not fail: expected exec error") |
| } else if errors.Is(err, ErrDot) { |
| t.Fatalf("Run returned unexpected error ErrDot: want error like ENOEXEC: %q", err) |
| } |
| }) |
| } |
| }) |
| } |
| |
| // Test the behavior when the first entry in PATH is an absolute name for the |
| // current directory. |
| // |
| // On Windows, "." may or may not be implicitly included before the explicit |
| // %PATH%, depending on the process environment; |
| // see https://go.dev/issue/4394. |
| // |
| // If the relative entry from "." resolves to the same executable as what |
| // would be resolved from an absolute entry in %PATH% alone, LookPath should |
| // return the absolute version of the path instead of ErrDot. |
| // (See https://go.dev/issue/53536.) |
| // |
| // If PATH does not implicitly include "." (such as on Unix platforms, or on |
| // Windows configured with NoDefaultCurrentDirectoryInExePath), then this |
| // lookup should succeed regardless of the behavior for ".", so it may be |
| // useful to run as a control case even on those platforms. |
| t.Run(pathVar+"=$PWD", func(t *testing.T) { |
| t.Setenv(pathVar, tmpDir+string(filepath.ListSeparator)+origPath) |
| good := filepath.Join(tmpDir, "execabs-test") |
| if found, err := LookPath(good); err != nil || !strings.HasPrefix(found, good) { |
| t.Fatalf(`LookPath(%#q) = %#q, %v, want \"%s...\", nil`, good, found, err, good) |
| } |
| |
| if found, err := LookPath("execabs-test"); err != nil || !strings.HasPrefix(found, good) { |
| t.Fatalf(`LookPath(%#q) = %#q, %v, want \"%s...\", nil`, "execabs-test", found, err, good) |
| } |
| |
| cmd := Command("execabs-test") |
| if cmd.Err != nil { |
| t.Fatalf("Command(%#q).Err = %v; want nil", "execabs-test", cmd.Err) |
| } |
| }) |
| |
| t.Run(pathVar+"=$OTHER", func(t *testing.T) { |
| // Control case: if the lookup returns ErrDot when PATH is empty, then we |
| // know that PATH implicitly includes ".". If it does not, then we don't |
| // expect to see ErrDot at all in this test (because the path will be |
| // unambiguously absolute). |
| wantErrDot := false |
| t.Setenv(pathVar, "") |
| if found, err := LookPath("execabs-test"); errors.Is(err, ErrDot) { |
| wantErrDot = true |
| } else if err == nil { |
| t.Fatalf(`with PATH='', LookPath(%#q) = %#q; want non-nil error`, "execabs-test", found) |
| } |
| |
| // Set PATH to include an explicit directory that contains a completely |
| // independent executable that happens to have the same name as an |
| // executable in ".". If "." is included implicitly, looking up the |
| // (unqualified) executable name will return ErrDot; otherwise, the |
| // executable in "." should have no effect and the lookup should |
| // unambiguously resolve to the directory in PATH. |
| |
| dir := t.TempDir() |
| executable := "execabs-test" |
| if runtime.GOOS == "windows" { |
| executable += ".exe" |
| } |
| if err := os.WriteFile(filepath.Join(dir, executable), []byte{1, 2, 3}, 0777); err != nil { |
| t.Fatal(err) |
| } |
| t.Setenv(pathVar, dir+string(filepath.ListSeparator)+origPath) |
| |
| found, err := LookPath("execabs-test") |
| if wantErrDot { |
| wantFound := filepath.Join(".", executable) |
| if found != wantFound || !errors.Is(err, ErrDot) { |
| t.Fatalf(`LookPath(%#q) = %#q, %v, want %#q, Is ErrDot`, "execabs-test", found, err, wantFound) |
| } |
| } else { |
| wantFound := filepath.Join(dir, executable) |
| if found != wantFound || err != nil { |
| t.Fatalf(`LookPath(%#q) = %#q, %v, want %#q, nil`, "execabs-test", found, err, wantFound) |
| } |
| } |
| }) |
| } |
