clear: Port to LibMain :^)

Author: https://github.com/kennethmyhra
Commit: d86c84a700
Pull-request: https://github.com/SerenityOS/serenity/pull/11101
Reviewed-by: https://github.com/awesomekling
Reviewed-by: https://github.com/bgianfo ✅
Reviewed-by: https://github.com/creator1creeper1 ✅
Reviewed-by: https://github.com/kleinesfilmroellchen ✅

Userland/Utilities/CMakeLists.txt

@@ -68,6 +68,7 @@ target_link_libraries(chgrp LibMain)
 target_link_libraries(chown LibMain)
 target_link_libraries(chres LibGUI LibMain)
 target_link_libraries(cksum LibCrypto LibMain)
+target_link_libraries(clear LibMain)
 target_link_libraries(config LibConfig)
 target_link_libraries(copy LibGUI LibMain)
 target_link_libraries(cp LibMain)

Userland/Utilities/clear.cpp

@@ -4,15 +4,13 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <LibCore/System.h>
+#include <LibMain/Main.h>
 #include <stdio.h>
-#include <unistd.h>
 
-int main(int, char**)
+ErrorOr<int> serenity_main(Main::Arguments)
 {
-    if (pledge("stdio", nullptr) < 0) {
-        perror("pledge");
-        return 1;
-    }
+    TRY(Core::System::pledge("stdio", nullptr));
     printf("\033[3J\033[H\033[2J");
     fflush(stdout);
     return 0;