Add support for pwd -P

interp/builtin.go

@@ -184,7 +184,27 @@ func (r *Runner) builtinCode(ctx context.Context, pos syntax.Pos, name string, a
 			return 2
 		}
 	case "pwd":
-		r.outf("%s\n", r.envGet("PWD"))
+		switch len(args) {
+		case 0:
+			r.outf("%s\n", r.envGet("PWD"))
+		case 1:
+			switch args[0] {
+			case "-L":
+				r.outf("%s\n", r.envGet("PWD"))
+			case "-P":
+				if path, err := filepath.EvalSymlinks(r.envGet("PWD")); err == nil {
+					r.outf("%s\n", path)
+				} else {
+					r.setErr(err)
+				}
+			default:
+				r.errf("invalid option: %q\n", args[0])
+				return 2
+			}
+		default:
+			r.errf("pwd cannot take multiple arguments\n")
+			return 1
+		}
 	case "cd":
 		var path string
 		switch len(args) {

interp/interp_test.go

@@ -906,6 +906,22 @@ var runTests = []runTest{
 		`mkdir a; ln -s a b; [[ $(cd a && pwd) == "$(cd b && pwd)" ]]; echo $?`,
 		"1\n",
 	},
+	{
+		`pwd -a`,
+		"invalid option: \"-a\"\nexit status 2",
+	},
+	{
+		`pwd -L -P`,
+		"pwd cannot take multiple arguments\nexit status 1",
+	},
+	{
+		`mkdir a; ln -s a b; [[ "$(cd a && pwd -P)" == "$(cd b && pwd -P)" ]]`,
+		"",
+	},
+	{
+		`[[ "$(pwd)" == "$(pwd -L)" ]]`,
+		"",
+	},
 
 	// dirs/pushd/popd
 	{"set -- $(dirs); echo $# ${#DIRSTACK[@]}", "1 1\n"},