From 5c0c1261228b7e9cdb58a4ba615aa9bcde9b6bee Mon Sep 17 00:00:00 2001
From: Ali Mohammad Pur <ali.mpfard@gmail.com>
Date: Sun, 9 Jan 2022 11:41:53 +0330
Subject: [PATCH] Shell: Add a "noop" builtin aliased to ":"

POSIX comes up with such silly names sometimes...
This builtin does nothing. at all.
---
 Userland/Shell/Builtin.cpp | 11 +++++++++++
 Userland/Shell/Shell.h     |  5 ++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/Userland/Shell/Builtin.cpp b/Userland/Shell/Builtin.cpp
index ea5b04cf80..baf863c88f 100644
--- a/Userland/Shell/Builtin.cpp
+++ b/Userland/Shell/Builtin.cpp
@@ -25,6 +25,11 @@ extern char** environ;
 
 namespace Shell {
 
+int Shell::builtin_noop(int, const char**)
+{
+    return 0;
+}
+
 int Shell::builtin_dump(int argc, const char** argv)
 {
     if (argc != 2)
@@ -1142,6 +1147,9 @@ bool Shell::run_builtin(const AST::Command& command, const NonnullRefPtrVector<A
     Core::EventLoop loop;
     setup_signals();
 
+    if (name == ":"sv)
+        name = "noop"sv;
+
 #define __ENUMERATE_SHELL_BUILTIN(builtin)                               \
     if (name == #builtin) {                                              \
         retval = builtin_##builtin(argv.size() - 1, argv.data());        \
@@ -1160,6 +1168,9 @@ bool Shell::run_builtin(const AST::Command& command, const NonnullRefPtrVector<A
 
 bool Shell::has_builtin(StringView name) const
 {
+    if (name == ":"sv)
+        return true;
+
 #define __ENUMERATE_SHELL_BUILTIN(builtin) \
     if (name == #builtin) {                \
         return true;                       \
diff --git a/Userland/Shell/Shell.h b/Userland/Shell/Shell.h
index 91c960d2e4..12e2f222a9 100644
--- a/Userland/Shell/Shell.h
+++ b/Userland/Shell/Shell.h
@@ -48,7 +48,8 @@
     __ENUMERATE_SHELL_BUILTIN(bg)      \
     __ENUMERATE_SHELL_BUILTIN(wait)    \
     __ENUMERATE_SHELL_BUILTIN(dump)    \
-    __ENUMERATE_SHELL_BUILTIN(kill)
+    __ENUMERATE_SHELL_BUILTIN(kill)    \
+    __ENUMERATE_SHELL_BUILTIN(noop)
 
 #define ENUMERATE_SHELL_OPTIONS()                                                                                    \
     __ENUMERATE_SHELL_OPTION(inline_exec_keep_empty_segments, false, "Keep empty segments in inline execute $(...)") \
@@ -333,6 +334,8 @@ private:
         ENUMERATE_SHELL_BUILTINS()
 
 #undef __ENUMERATE_SHELL_BUILTIN
+
+            ":", // POSIX-y name for "noop".
     };
 
     bool m_should_ignore_jobs_on_next_exit { false };