fixed bash-for-windows

internal/shell/exec.go

@@ -58,6 +58,12 @@ func splitPipe(input string) []string {
 		case c == '"' && !inSingle && parenDepth == 0:
 			inDouble = !inDouble
 			current.WriteByte(c)
+		// Process substitution <(...): don't split | inside.
+		case c == '<' && !inSingle && !inDouble && i+1 < len(input) && input[i+1] == '(':
+			parenDepth++
+			current.WriteByte('<')
+			current.WriteByte('(')
+			i++
 		case c == '$' && !inSingle && !inDouble && i+1 < len(input) && input[i+1] == '(':
 			pendingDollar = true
 			current.WriteByte(c)
@@ -154,6 +160,15 @@ func (s *Shell) executeCommand(input string) error {
 		return nil
 	}
 
+	// { cmd; cmd; } command group
+	if strings.HasPrefix(input, "{") {
+		end := strings.LastIndex(input, "}")
+		if end > 0 {
+			inner := strings.TrimSpace(input[1:end])
+			return s.Execute(inner)
+		}
+	}
+
 	// Detect array assignment NAME=(...) or NAME+=(...)
 	if name, appendMode, elems, ok := s.parseArrayAssign(input); ok {
 		if appendMode {
@@ -264,6 +279,20 @@ func (s *Shell) extractRedirects(tokens []string) ([]string, []redirect) {
 		case strings.HasPrefix(tok, ">") && len(tok) > 1:
 			redirects = append(redirects, redirect{1, ">", tok[1:]})
 			i++
+		// <<< here-string
+		case tok == "<<<":
+			if i+1 < len(tokens) {
+				val := tokens[i+1] + "\n"
+				tmpf, err := os.CreateTemp("", "herestr*")
+				if err == nil {
+					tmpf.WriteString(val)
+					tmpf.Close()
+					redirects = append(redirects, redirect{0, "<", tmpf.Name()})
+				}
+				i += 2
+			} else {
+				i++
+			}
 		// < (stdin) — also handle process substitution <(...)
 		case tok == "<":
 			if i+1 < len(tokens) {
@@ -311,7 +340,11 @@ func (s *Shell) withRedirects(redirects []redirect, fn func() error) error {
 		}
 	}()
 
-	for _, r := range redirects {
+	for i, r := range redirects {
+		if r.dest == "/dev/null" {
+			redirects[i].dest = os.DevNull
+			r = redirects[i]
+		}
 		switch r.mode {
 		case ">":
 			if r.dest == "&1" {
@@ -361,6 +394,20 @@ func (s *Shell) executeExternal(cmdName string, args []string) error {
 		fmt.Fprintf(s.Stderr, "%s: command not found\n", cmdName)
 		return exitCodeErr{127}
 	}
+
+	// If the file is a bash/sh script, run it through our own interpreter.
+	// This avoids the CRLF shebang problem (#!/usr/bin/env bash\r) and lets
+	// us execute scripts that have no .exe extension on Windows.
+	if data, err := os.ReadFile(path); err == nil && isShellScript(data) {
+		sh := New()
+		sh.Stdin = s.Stdin
+		sh.Stdout = s.Stdout
+		sh.Stderr = s.Stderr
+		sh.SetArgs(args)
+		sh.SetVar("0", path)
+		return sh.Execute(string(data))
+	}
+
 	cmd := exec.Command(path, args...)
 	cmd.Stdin = s.Stdin
 	cmd.Stdout = s.Stdout
@@ -374,6 +421,25 @@ func (s *Shell) executeExternal(cmdName string, args []string) error {
 	return err
 }
 
+// isShellScript returns true when data begins with a #!/…bash or #!/…sh shebang.
+func isShellScript(data []byte) bool {
+	if len(data) < 2 || data[0] != '#' || data[1] != '!' {
+		return false
+	}
+	nl := bytes.IndexByte(data, '\n')
+	if nl < 0 {
+		nl = len(data)
+	}
+	line := strings.TrimRight(string(data[:nl]), "\r")
+	for _, word := range strings.Fields(line[2:]) {
+		base := filepath.Base(word)
+		if base == "bash" || base == "sh" {
+			return true
+		}
+	}
+	return false
+}
+
 func (s *Shell) executeCommandBg(input string) error {
 	tokens := s.tokenize(input)
 	if len(tokens) == 0 {