From 92e6532bf139aca0be568b545e8c0a47dc7f665f Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Thu, 16 Dec 2021 19:24:58 +0100
Subject: [PATCH] LibCore: Add syscall wrapper for isatty()

---
 Userland/Libraries/LibCore/System.cpp | 8 ++++++++
 Userland/Libraries/LibCore/System.h   | 1 +
 2 files changed, 9 insertions(+)

diff --git a/Userland/Libraries/LibCore/System.cpp b/Userland/Libraries/LibCore/System.cpp
index 423d0b1ca0..e99cf059c8 100644
--- a/Userland/Libraries/LibCore/System.cpp
+++ b/Userland/Libraries/LibCore/System.cpp
@@ -416,4 +416,12 @@ ErrorOr<void> setegid(gid_t gid)
     return {};
 }
 
+ErrorOr<bool> isatty(int fd)
+{
+    int rc = ::isatty(fd);
+    if (rc < 0)
+        return Error::from_syscall("isatty"sv, -errno);
+    return rc == 1;
+}
+
 }
diff --git a/Userland/Libraries/LibCore/System.h b/Userland/Libraries/LibCore/System.h
index 47f2d6c92f..f942c51c40 100644
--- a/Userland/Libraries/LibCore/System.h
+++ b/Userland/Libraries/LibCore/System.h
@@ -59,5 +59,6 @@ ErrorOr<void> setuid(uid_t);
 ErrorOr<void> seteuid(uid_t);
 ErrorOr<void> setgid(gid_t);
 ErrorOr<void> setegid(gid_t);
+ErrorOr<bool> isatty(int fd);
 
 }