diff --git a/libc/config/linux/x86_64/entrypoints.txt b/libc/config/linux/x86_64/entrypoints.txt
index bb4973628d58..4103ee0331a2 100644
--- a/libc/config/linux/x86_64/entrypoints.txt
+++ b/libc/config/linux/x86_64/entrypoints.txt
@@ -251,6 +251,9 @@ set(TARGET_LIBC_ENTRYPOINTS
     # sys/ioctl.h entrypoints
     libc.src.sys.ioctl.ioctl
 
+    # sys/ipc.h entrypoints
+    libc.src.sys.ipc.ftok
+
     # sys/mman.h entrypoints
     libc.src.sys.mman.madvise
     libc.src.sys.mman.mincore
diff --git a/libc/config/linux/x86_64/headers.txt b/libc/config/linux/x86_64/headers.txt
index d0f62eb104dc..0669cc30aead 100644
--- a/libc/config/linux/x86_64/headers.txt
+++ b/libc/config/linux/x86_64/headers.txt
@@ -38,6 +38,7 @@ set(TARGET_PUBLIC_HEADERS
     libc.include.sys_auxv
     libc.include.sys_epoll
     libc.include.sys_ioctl
+    libc.include.sys_ipc
     libc.include.sys_mman
     libc.include.sys_prctl
     libc.include.sys_queue
diff --git a/libc/hdr/types/CMakeLists.txt b/libc/hdr/types/CMakeLists.txt
index 3385fe81fe22..03e7066f83a0 100644
--- a/libc/hdr/types/CMakeLists.txt
+++ b/libc/hdr/types/CMakeLists.txt
@@ -233,6 +233,15 @@ add_proxy_header_library(
     libc.include.sys_time
 )
 
+add_proxy_header_library(
+  key_t
+  HDRS
+    key_t.h
+  FULL_BUILD_DEPENDS
+    libc.include.llvm-libc-types.key_t
+    libc.include.sys_ipc
+)
+
 add_proxy_header_library(
   pid_t
   HDRS
diff --git a/libc/hdr/types/key_t.h b/libc/hdr/types/key_t.h
new file mode 100644
index 000000000000..478522a93a19
--- /dev/null
+++ b/libc/hdr/types/key_t.h
@@ -0,0 +1,22 @@
+//===-- Proxy for key_t ---------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_HDR_TYPES_KEY_T_H
+#define LLVM_LIBC_HDR_TYPES_KEY_T_H
+
+#ifdef LIBC_FULL_BUILD
+
+#include "include/llvm-libc-types/key_t.h"
+
+#else // Overlay mode
+
+#include <sys/ipc.h>
+
+#endif // LLVM_LIBC_FULL_BUILD
+
+#endif // LLVM_LIBC_HDR_TYPES_KEY_T_H
diff --git a/libc/include/CMakeLists.txt b/libc/include/CMakeLists.txt
index c6254aafe384..5ffee68b5feb 100644
--- a/libc/include/CMakeLists.txt
+++ b/libc/include/CMakeLists.txt
@@ -557,6 +557,20 @@ add_header_macro(
     .llvm-libc-macros.sys_ioctl_macros
 )
 
+add_header_macro(
+  sys_ipc
+  ../libc/include/sys/ipc.yaml
+  sys/ipc.h
+  DEPENDS
+    .llvm_libc_common_h
+    .llvm-libc-macros.sys_ipc_macros
+    .llvm-libc-types.key_t
+    .llvm-libc-types.uid_t
+    .llvm-libc-types.gid_t
+    .llvm-libc-types.mode_t
+    .llvm-libc-types.struct_ipc_perm
+)
+
 add_header_macro(
   sys_mman
   ../libc/include/sys/mman.yaml
@@ -708,6 +722,7 @@ add_header_macro(
     .llvm-libc-types.dev_t
     .llvm-libc-types.gid_t
     .llvm-libc-types.ino_t
+    .llvm-libc-types.key_t
     .llvm-libc-types.mode_t
     .llvm-libc-types.nlink_t
     .llvm-libc-types.off_t
diff --git a/libc/include/llvm-libc-macros/CMakeLists.txt b/libc/include/llvm-libc-macros/CMakeLists.txt
index b16337cccd58..553879e27d3d 100644
--- a/libc/include/llvm-libc-macros/CMakeLists.txt
+++ b/libc/include/llvm-libc-macros/CMakeLists.txt
@@ -226,6 +226,12 @@ add_macro_header(
     sys-ioctl-macros.h
 )
 
+add_macro_header(
+  sys_ipc_macros
+  HDR
+    sys-ipc-macros.h
+)
+
 add_macro_header(
   sys_stat_macros
   HDR
diff --git a/libc/include/llvm-libc-macros/linux/CMakeLists.txt b/libc/include/llvm-libc-macros/linux/CMakeLists.txt
index 61da55eabd40..60376641b50f 100644
--- a/libc/include/llvm-libc-macros/linux/CMakeLists.txt
+++ b/libc/include/llvm-libc-macros/linux/CMakeLists.txt
@@ -34,6 +34,12 @@ add_header(
     sys-ioctl-macros.h
 )
 
+add_header(
+  sys_ipc_macros
+  HDR
+    sys-ipc-macros.h
+)
+
 add_header(
   sys_random_macros
   HDR
diff --git a/libc/include/llvm-libc-macros/linux/sys-ipc-macros.h b/libc/include/llvm-libc-macros/linux/sys-ipc-macros.h
new file mode 100644
index 000000000000..87546ac314d8
--- /dev/null
+++ b/libc/include/llvm-libc-macros/linux/sys-ipc-macros.h
@@ -0,0 +1,24 @@
+//===-- Definition of macros from sys/ipc.h -------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_MACROS_LINUX_SYS_IPC_MACROS_H
+#define LLVM_LIBC_MACROS_LINUX_SYS_IPC_MACROS_H
+
+#define IPC_PRIVATE 0
+
+// Resource get request flags.
+#define IPC_CREAT 01000
+#define IPC_EXCL 02000
+#define IPC_NOWAIT 04000
+
+// Control commands used with semctl, msgctl, and shmctl.
+#define IPC_RMID 0
+#define IPC_SET 1
+#define IPC_STAT 2
+
+#endif // LLVM_LIBC_MACROS_LINUX_SYS_IPC_MACROS_H
diff --git a/libc/include/llvm-libc-macros/sys-ipc-macros.h b/libc/include/llvm-libc-macros/sys-ipc-macros.h
new file mode 100644
index 000000000000..37e7e45456d2
--- /dev/null
+++ b/libc/include/llvm-libc-macros/sys-ipc-macros.h
@@ -0,0 +1,16 @@
+//===-- Macros defined in sys/ipc.h header file ---------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_MACROS_SYS_IPC_MACROS_H
+#define LLVM_LIBC_MACROS_SYS_IPC_MACROS_H
+
+#ifdef __linux__
+#include "linux/sys-ipc-macros.h"
+#endif
+
+#endif // LLVM_LIBC_MACROS_SYS_IPC_MACROS_H
diff --git a/libc/include/llvm-libc-types/CMakeLists.txt b/libc/include/llvm-libc-types/CMakeLists.txt
index dc36dfeadba5..eb8356cbfb8b 100644
--- a/libc/include/llvm-libc-types/CMakeLists.txt
+++ b/libc/include/llvm-libc-types/CMakeLists.txt
@@ -42,6 +42,7 @@ add_header(imaxdiv_t HDR imaxdiv_t.h)
 add_header(in_addr_t HDR in_addr_t.h)
 add_header(in_addr HDR in_addr.h DEPENDS .in_addr_t)
 add_header(ino_t HDR ino_t.h)
+add_header(key_t HDR key_t.h)
 add_header(mbstate_t HDR mbstate_t.h)
 add_header(mode_t HDR mode_t.h)
 add_header(mtx_t HDR mtx_t.h DEPENDS .__futex_word .__mutex_type)
@@ -79,6 +80,15 @@ add_header(dl_info HDR Dl_info.h)
 add_header(struct_f_owner_ex HDR struct_f_owner_ex.h DEPENDS .pid_t)
 add_header(struct_flock HDR struct_flock.h DEPENDS .off_t .pid_t)
 add_header(struct_flock64 HDR struct_flock64.h DEPENDS .off64_t .pid_t)
+add_header(
+  struct_ipc_perm
+  HDR struct_ipc_perm.h
+  DEPENDS
+    .key_t
+    .uid_t
+    .gid_t
+    .mode_t
+)
 add_header(struct_pollfd HDR struct_pollfd.h)
 add_header(struct_rlimit HDR struct_rlimit.h DEPENDS .rlim_t)
 add_header(struct_sched_param HDR struct_sched_param.h)
diff --git a/libc/include/llvm-libc-types/key_t.h b/libc/include/llvm-libc-types/key_t.h
new file mode 100644
index 000000000000..151546988086
--- /dev/null
+++ b/libc/include/llvm-libc-types/key_t.h
@@ -0,0 +1,14 @@
+//===-- Definition of key_t type ------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TYPES_KEY_T_H
+#define LLVM_LIBC_TYPES_KEY_T_H
+
+typedef __INT32_TYPE__ key_t;
+
+#endif // LLVM_LIBC_TYPES_KEY_T_H
diff --git a/libc/include/llvm-libc-types/struct_ipc_perm.h b/libc/include/llvm-libc-types/struct_ipc_perm.h
new file mode 100644
index 000000000000..5dc1c12427a4
--- /dev/null
+++ b/libc/include/llvm-libc-types/struct_ipc_perm.h
@@ -0,0 +1,34 @@
+//===-- Definition of struct ipc_perm -------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_TYPES_STRUCT_IPC_PERM_H
+#define LLVM_LIBC_TYPES_STRUCT_IPC_PERM_H
+
+#include "gid_t.h"
+#include "key_t.h"
+#include "mode_t.h"
+#include "uid_t.h"
+
+#ifdef __linux__
+struct ipc_perm {
+  key_t __key;
+  uid_t uid;
+  gid_t gid;
+  uid_t cuid;
+  gid_t cgid;
+  mode_t mode;
+  unsigned short __seq;
+  unsigned short __padding;
+  unsigned long __unused_0;
+  unsigned long __unused_1;
+};
+#else
+#error "ipc_perm not defined for the target platform"
+#endif
+
+#endif // LLVM_LIBC_TYPES_STRUCT_IPC_PERM_H
diff --git a/libc/include/sys/ipc.yaml b/libc/include/sys/ipc.yaml
new file mode 100644
index 000000000000..77593af1dc0a
--- /dev/null
+++ b/libc/include/sys/ipc.yaml
@@ -0,0 +1,51 @@
+header: sys/ipc.h
+standards:
+  - posix
+  - linux
+macros:
+  - macro_name: IPC_PRIVATE
+    macro_header: sys-ipc-macros.h
+    standards:
+      - posix
+  - macro_name: IPC_CREAT
+    macro_header: sys-ipc-macros.h
+    standards:
+      - posix
+  - macro_name: IPC_EXCL
+    macro_header: sys-ipc-macros.h
+    standards:
+      - posix
+  - macro_name: IPC_NOWAIT
+    macro_header: sys-ipc-macros.h
+    standards:
+      - posix
+  - macro_name: IPC_RMID
+    macro_header: sys-ipc-macros.h
+    standards:
+      - posix
+  - macro_name: IPC_SET
+    macro_header: sys-ipc-macros.h
+    standards:
+      - posix
+  - macro_name: IPC_STAT
+    macro_header: sys-ipc-macros.h
+    standards:
+      - posix
+  - macro_name: IPC_INFO
+    macro_header: sys-ipc-macros.h
+    standards:
+      - linux
+types:
+  - type_name: key_t
+  - type_name: uid_t
+  - type_name: gid_t
+  - type_name: mode_t
+  - type_name: struct_ipc_perm
+functions:
+  - name: ftok
+    standards:
+      - posix
+    return_type: key_t
+    arguments:
+      - type: const char *
+      - type: int
diff --git a/libc/include/sys/types.yaml b/libc/include/sys/types.yaml
index a00429d3817e..126c597b3035 100644
--- a/libc/include/sys/types.yaml
+++ b/libc/include/sys/types.yaml
@@ -8,6 +8,7 @@ types:
   - type_name: dev_t
   - type_name: gid_t
   - type_name: ino_t
+  - type_name: key_t
   - type_name: mode_t
   - type_name: nlink_t
   - type_name: off_t
diff --git a/libc/src/sys/CMakeLists.txt b/libc/src/sys/CMakeLists.txt
index 0fa11e9eee69..1c17ec31a859 100644
--- a/libc/src/sys/CMakeLists.txt
+++ b/libc/src/sys/CMakeLists.txt
@@ -1,5 +1,6 @@
 add_subdirectory(auxv)
 add_subdirectory(epoll)
+add_subdirectory(ipc)
 add_subdirectory(mman)
 add_subdirectory(random)
 add_subdirectory(resource)
diff --git a/libc/src/sys/ipc/CMakeLists.txt b/libc/src/sys/ipc/CMakeLists.txt
new file mode 100644
index 000000000000..e20ac7e3f964
--- /dev/null
+++ b/libc/src/sys/ipc/CMakeLists.txt
@@ -0,0 +1,10 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+  add_subdirectory(${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+endif()
+
+add_entrypoint_object(
+  ftok
+  ALIAS
+  DEPENDS
+    .${LIBC_TARGET_OS}.ftok
+)
diff --git a/libc/src/sys/ipc/ftok.h b/libc/src/sys/ipc/ftok.h
new file mode 100644
index 000000000000..24603e626c08
--- /dev/null
+++ b/libc/src/sys/ipc/ftok.h
@@ -0,0 +1,21 @@
+//===-- Implementation header for ftok --------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_IPC_FTOK_H
+#define LLVM_LIBC_SRC_SYS_IPC_FTOK_H
+
+#include "hdr/types/key_t.h"
+#include "src/__support/macros/config.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+key_t ftok(const char *path, int id);
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_IPC_FTOK_H
diff --git a/libc/src/sys/ipc/linux/CMakeLists.txt b/libc/src/sys/ipc/linux/CMakeLists.txt
new file mode 100644
index 000000000000..d5b2d1b8ab77
--- /dev/null
+++ b/libc/src/sys/ipc/linux/CMakeLists.txt
@@ -0,0 +1,23 @@
+add_header_library(
+  kernel_statx
+  HDRS
+    kernel_statx.h
+  DEPENDS
+    libc.hdr.fcntl_macros
+    libc.include.sys_syscall
+    libc.src.__support.error_or
+    libc.src.__support.OSUtil.osutil
+)
+
+add_entrypoint_object(
+  ftok
+  SRCS
+    ftok.cpp
+  HDRS
+    ../ftok.h
+  DEPENDS
+    .kernel_statx
+    libc.hdr.types.key_t
+    libc.src.__support.common
+    libc.src.errno.errno
+)
diff --git a/libc/src/sys/ipc/linux/ftok.cpp b/libc/src/sys/ipc/linux/ftok.cpp
new file mode 100644
index 000000000000..28762ac6e33f
--- /dev/null
+++ b/libc/src/sys/ipc/linux/ftok.cpp
@@ -0,0 +1,38 @@
+//===-- Linux implementation of ftok --------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#include "src/sys/ipc/ftok.h"
+
+#include "src/__support/common.h"
+#include "src/__support/error_or.h"
+#include "src/__support/libc_errno.h"
+
+#include "kernel_statx.h"
+
+namespace LIBC_NAMESPACE_DECL {
+
+LLVM_LIBC_FUNCTION(key_t, ftok, (const char *path, int id)) {
+  struct statx xbuf;
+
+  ErrorOr<int> err = statx_for_ftok(path, xbuf);
+
+  if (!err.has_value()) {
+    libc_errno = err.error();
+    return -1;
+  }
+
+  // key layout based on user input and file stats metadata
+  // 31            24              16             0
+  // +-------------+---------------+--------------+
+  // user input id + minor dev num + file inode num
+  return static_cast<key_t>(
+      ((id & 0xff) << 24) |
+      ((static_cast<int>(xbuf.stx_dev_minor) & 0xff) << 16) |
+      (static_cast<int>(xbuf.stx_ino) & 0xffff));
+}
+
+} // namespace LIBC_NAMESPACE_DECL
diff --git a/libc/src/sys/ipc/linux/kernel_statx.h b/libc/src/sys/ipc/linux/kernel_statx.h
new file mode 100644
index 000000000000..7613e1b50f20
--- /dev/null
+++ b/libc/src/sys/ipc/linux/kernel_statx.h
@@ -0,0 +1,34 @@
+//===-- Wrapper over SYS_statx syscall for ftok ---------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIBC_SRC_SYS_IPC_LINUX_KERNEL_STATX_H
+#define LLVM_LIBC_SRC_SYS_IPC_LINUX_KERNEL_STATX_H
+
+#include "hdr/fcntl_macros.h"
+#include "src/__support/OSUtil/syscall.h"
+#include "src/__support/error_or.h"
+#include "sys/syscall.h"
+
+#include <linux/stat.h>
+
+namespace LIBC_NAMESPACE_DECL {
+
+LIBC_INLINE ErrorOr<int> statx_for_ftok(const char *path, struct statx &xbuf) {
+
+  // store the file stats metadata into xbuf
+  int ret = LIBC_NAMESPACE::syscall_impl<int>(SYS_statx, AT_FDCWD, path, 0,
+                                              STATX_BASIC_STATS, &xbuf);
+
+  if (ret < 0)
+    return Error(-ret);
+  return 0;
+}
+
+} // namespace LIBC_NAMESPACE_DECL
+
+#endif // LLVM_LIBC_SRC_SYS_IPC_LINUX_KERNEL_STATX_H
diff --git a/libc/test/src/sys/CMakeLists.txt b/libc/test/src/sys/CMakeLists.txt
index 13bf91eef04b..3b5ea64fb144 100644
--- a/libc/test/src/sys/CMakeLists.txt
+++ b/libc/test/src/sys/CMakeLists.txt
@@ -11,6 +11,7 @@ add_subdirectory(wait)
 add_subdirectory(prctl)
 add_subdirectory(auxv)
 add_subdirectory(epoll)
+add_subdirectory(ipc)
 add_subdirectory(uio)
 add_subdirectory(time)
 add_subdirectory(ioctl)
diff --git a/libc/test/src/sys/ipc/CMakeLists.txt b/libc/test/src/sys/ipc/CMakeLists.txt
new file mode 100644
index 000000000000..b4bbe81c92ff
--- /dev/null
+++ b/libc/test/src/sys/ipc/CMakeLists.txt
@@ -0,0 +1,3 @@
+if(EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/${LIBC_TARGET_OS})
+  add_subdirectory(${LIBC_TARGET_OS})
+endif()
diff --git a/libc/test/src/sys/ipc/linux/CMakeLists.txt b/libc/test/src/sys/ipc/linux/CMakeLists.txt
new file mode 100644
index 000000000000..21d501a3029e
--- /dev/null
+++ b/libc/test/src/sys/ipc/linux/CMakeLists.txt
@@ -0,0 +1,19 @@
+add_custom_target(libc_sys_ipc_unittests)
+
+add_libc_unittest(
+  ftok_test
+  SUITE
+    libc_sys_ipc_unittests
+  SRCS
+    ftok_test.cpp
+  DEPENDS
+    libc.hdr.fcntl_macros
+    libc.include.sys_ipc
+    libc.src.errno.errno
+    libc.src.fcntl.open
+    libc.src.sys.ipc.ftok
+    libc.src.unistd.close
+    libc.src.unistd.unlink
+    libc.test.UnitTest.ErrnoCheckingTest
+    libc.test.UnitTest.ErrnoSetterMatcher
+)
diff --git a/libc/test/src/sys/ipc/linux/ftok_test.cpp b/libc/test/src/sys/ipc/linux/ftok_test.cpp
new file mode 100644
index 000000000000..dd9a4702d439
--- /dev/null
+++ b/libc/test/src/sys/ipc/linux/ftok_test.cpp
@@ -0,0 +1,59 @@
+//===-- Unittests for ftok ------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "src/fcntl/open.h"
+#include "src/sys/ipc/ftok.h"
+#include "src/unistd/close.h"
+#include "src/unistd/unlink.h"
+#include "test/UnitTest/ErrnoCheckingTest.h"
+#include "test/UnitTest/ErrnoSetterMatcher.h"
+#include "test/UnitTest/Test.h"
+
+#include "hdr/fcntl_macros.h"
+
+using namespace LIBC_NAMESPACE::testing::ErrnoSetterMatcher;
+using LlvmLibcFtokTest = LIBC_NAMESPACE::testing::ErrnoCheckingTest;
+
+TEST_F(LlvmLibcFtokTest, InvalidPath) {
+  ASSERT_THAT(LIBC_NAMESPACE::ftok("no/such/path", 1), Fails(ENOENT));
+}
+
+TEST_F(LlvmLibcFtokTest, DeterministicForPathAndId) {
+  // create a file
+  constexpr const char *TEST_FILE_NAME = "ftok.test";
+  auto TEST_FILE = libc_make_test_file_path(TEST_FILE_NAME);
+
+  // we first ensure such file exist and set to readable, writable
+  int fd = LIBC_NAMESPACE::open(TEST_FILE, O_CREAT | O_WRONLY, 0600);
+  ASSERT_GT(fd, -1);
+  ASSERT_ERRNO_SUCCESS();
+  ASSERT_THAT(LIBC_NAMESPACE::close(fd), Succeeds(0));
+
+  // create keys based on file path and user specified int
+  key_t key1 = LIBC_NAMESPACE::ftok(TEST_FILE, 'A');
+  ASSERT_NE(key1, key_t(-1));
+  ASSERT_ERRNO_SUCCESS();
+
+  key_t key2 = LIBC_NAMESPACE::ftok(TEST_FILE, 'A');
+  ASSERT_NE(key2, key_t(-1));
+  ASSERT_ERRNO_SUCCESS();
+
+  // key should be identical if both inputs are the same
+  ASSERT_EQ(key1, key2);
+
+  // create another key
+  key_t key3 = LIBC_NAMESPACE::ftok(TEST_FILE, 'B');
+  ASSERT_NE(key3, key_t(-1));
+  ASSERT_ERRNO_SUCCESS();
+
+  // key should be different if any input is different
+  ASSERT_NE(key1, key3);
+
+  // delete the file
+  ASSERT_THAT(LIBC_NAMESPACE::unlink(TEST_FILE), Succeeds(0));
+}