Current File : //usr/local/go119/src/os/exec/dot_test.go
// 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)
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)
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)
}
}
})
}
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