From cf1baddb670accbb44526a32daf8648bc3fec023 Mon Sep 17 00:00:00 2001
From: Jelle Raaijmakers <jelle@gmta.nl>
Date: Tue, 29 Mar 2022 22:47:06 +0200
Subject: [PATCH] LibC: Implement `getdtablesize()`

---
 Userland/Libraries/LibC/unistd.cpp | 9 +++++++++
 Userland/Libraries/LibC/unistd.h   | 1 +
 2 files changed, 10 insertions(+)

diff --git a/Userland/Libraries/LibC/unistd.cpp b/Userland/Libraries/LibC/unistd.cpp
index 398c44e8f90..386de582609 100644
--- a/Userland/Libraries/LibC/unistd.cpp
+++ b/Userland/Libraries/LibC/unistd.cpp
@@ -23,6 +23,7 @@
 #include <string.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
+#include <sys/resource.h>
 #include <sys/select.h>
 #include <sys/stat.h>
 #include <sys/sysmacros.h>
@@ -980,4 +981,12 @@ int chroot(const char* path)
     dbgln("FIXME: chroot(\"{}\")", path);
     return -1;
 }
+
+// https://pubs.opengroup.org/onlinepubs/7908799/xsh/getdtablesize.html
+int getdtablesize()
+{
+    rlimit dtablesize;
+    int rc = getrlimit(RLIMIT_NOFILE, &dtablesize);
+    __RETURN_WITH_ERRNO(rc, dtablesize.rlim_cur, rc);
+}
 }
diff --git a/Userland/Libraries/LibC/unistd.h b/Userland/Libraries/LibC/unistd.h
index 24f6c48e08a..33009811691 100644
--- a/Userland/Libraries/LibC/unistd.h
+++ b/Userland/Libraries/LibC/unistd.h
@@ -118,6 +118,7 @@ int unveil(const char* path, const char* permissions);
 char* getpass(const char* prompt);
 int pause(void);
 int chroot(const char*);
+int getdtablesize(void);
 
 enum {
     _PC_NAME_MAX,