From fbf91f41e7ae91ab559c1693ed3428b6b405a9f2 Mon Sep 17 00:00:00 2001
From: sin-ack <sin-ack@users.noreply.github.com>
Date: Sat, 16 Jul 2022 23:09:03 +0000
Subject: [PATCH] Shell: Add the |& construct for piping stderr along with
 stdout

When |& is typed, stderr will be piped to stdout before the actual
piping happens. This behaves basically like a 2>&1 | (and the
underlying implementation transforms it to that anyway).
---
 Userland/Shell/Parser.cpp | 12 ++++++++++++
 Userland/Shell/Parser.h   |  4 ++--
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/Userland/Shell/Parser.cpp b/Userland/Shell/Parser.cpp
index 49b3a27fe3..b6eb1d8444 100644
--- a/Userland/Shell/Parser.cpp
+++ b/Userland/Shell/Parser.cpp
@@ -510,6 +510,18 @@ RefPtr<AST::Node> Parser::parse_pipe_sequence()
 
     auto before_pipe = save_offset();
     consume();
+    auto also_pipe_stderr = peek() == '&';
+    if (also_pipe_stderr) {
+        consume();
+
+        RefPtr<AST::Node> redirection;
+        {
+            auto redirection_start = push_start();
+            redirection = create<AST::Fd2FdRedirection>(STDERR_FILENO, STDOUT_FILENO);
+        }
+
+        left = create<AST::Join>(left.release_nonnull(), redirection.release_nonnull());
+    }
 
     if (auto pipe_seq = parse_pipe_sequence()) {
         return create<AST::Pipe>(left.release_nonnull(), pipe_seq.release_nonnull()); // Pipe
diff --git a/Userland/Shell/Parser.h b/Userland/Shell/Parser.h
index 41a2a333fe..802489d9b0 100644
--- a/Userland/Shell/Parser.h
+++ b/Userland/Shell/Parser.h
@@ -200,9 +200,9 @@ heredoc_entries :: { .*? (heredoc_entry) '\n' } [each heredoc_entries]
 variable_decls :: identifier '=' expression (' '+ variable_decls)? ' '*
                 | identifier '=' '(' pipe_sequence ')' (' '+ variable_decls)? ' '*
 
-pipe_sequence :: command '|' pipe_sequence
+pipe_sequence :: command '|' '&'? pipe_sequence
                | command
-               | control_structure '|' pipe_sequence
+               | control_structure '|' '&'? pipe_sequence
                | control_structure
 
 control_structure[c] :: for_expr