LibC: Implement flock(2) using fcntl's F_SETLK

While flock is not a posix interface, it exists on linux and all BSDs as far as I am aware.
Author: https://github.com/petelliott Commit: 2ce8cca7b5 Pull-request: https://github.com/SerenityOS/serenity/pull/8878 Reviewed-by: https://github.com/alimpfard ✅
2025-08-03 14:50:18 +00:00 · 2021-07-18 23:55:13 -06:00 · 2021-07-18 23:55:13 -06:00 · 2ce8cca7b5 · 2024-07-18 08:41:03 +09:00
commit 2ce8cca7b5
parent 3fa2816642
3 changed files with 40 additions and 0 deletions
--- a/Userland/Libraries/LibC/sys/file.h
+++ b/Userland/Libraries/LibC/sys/file.h
@ -5,3 +5,16 @@
 */

 #pragma once
+
+#include <sys/cdefs.h>
+
+__BEGIN_DECLS
+
+#define LOCK_SH 0
+#define LOCK_EX 1
+#define LOCK_UN 2
+#define LOCK_NB (1 << 2)
+
+int flock(int fd, int operation);
+
+__END_DECLS