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-rw-r--r--src/os/exec/lp_unix.go59
1 files changed, 59 insertions, 0 deletions
diff --git a/src/os/exec/lp_unix.go b/src/os/exec/lp_unix.go
new file mode 100644
index 0000000..66c1df7
--- /dev/null
+++ b/src/os/exec/lp_unix.go
@@ -0,0 +1,59 @@
+// Copyright 2010 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.
+
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package exec
+
+import (
+ "errors"
+ "io/fs"
+ "os"
+ "path/filepath"
+ "strings"
+)
+
+// ErrNotFound is the error resulting if a path search failed to find an executable file.
+var ErrNotFound = errors.New("executable file not found in $PATH")
+
+func findExecutable(file string) error {
+ d, err := os.Stat(file)
+ if err != nil {
+ return err
+ }
+ if m := d.Mode(); !m.IsDir() && m&0111 != 0 {
+ return nil
+ }
+ return fs.ErrPermission
+}
+
+// LookPath searches for an executable named file in the
+// directories named by the PATH environment variable.
+// If file contains a slash, it is tried directly and the PATH is not consulted.
+// The result may be an absolute path or a path relative to the current directory.
+func LookPath(file string) (string, error) {
+ // NOTE(rsc): I wish we could use the Plan 9 behavior here
+ // (only bypass the path if file begins with / or ./ or ../)
+ // but that would not match all the Unix shells.
+
+ if strings.Contains(file, "/") {
+ err := findExecutable(file)
+ if err == nil {
+ return file, nil
+ }
+ return "", &Error{file, err}
+ }
+ path := os.Getenv("PATH")
+ for _, dir := range filepath.SplitList(path) {
+ if dir == "" {
+ // Unix shell semantics: path element "" means "."
+ dir = "."
+ }
+ path := filepath.Join(dir, file)
+ if err := findExecutable(path); err == nil {
+ return path, nil
+ }
+ }
+ return "", &Error{file, ErrNotFound}
+}