3 files changed, 40 insertions, 0 deletions
diff --git a/compat/defs.hpp b/compat/defs.hpp
index b967833e..ff2171c3 100644
--- a/compat/defs.hpp
+++ b/compat/defs.hpp
@@ -90,4 +90,6 @@
 #define fm_ASAN 0
 #endif
 
+#ifndef fm_FILENAME_MAX
 #define fm_FILENAME_MAX (260)
+#endif
diff --git a/compat/os-file.cpp b/compat/os-file.cpp
new file mode 100644
index 00000000..0d8f95c2
--- /dev/null
+++ b/compat/os-file.cpp
@@ -0,0 +1,27 @@
+#include "os-file.hpp"
+#include "assert.hpp"
+#include <cerrno>
+#include <cr/StringView.h>
+
+#ifdef _WIN32
+#include <io.h>
+#define fm_os_access _access
+#else
+#include <unistd.h>
+#define fm_os_access access
+#endif
+
+namespace floormat::fs {
+
+bool file_exists(StringView name)
+{
+    fm_assert(name.flags() & StringViewFlag::NullTerminated);
+    fm_debug_assert(!name.find('\0'));
+    if (!fm_os_access(name.data(), F_OK))
+        return true;
+    int error = errno;
+    // just let it die if the file exists but can't be accessed
+    return error != ENOENT;
+}
+
+} // namespace floormat::fs
diff --git a/compat/os-file.hpp b/compat/os-file.hpp
new file mode 100644
index 00000000..8e7962bf
--- /dev/null
+++ b/compat/os-file.hpp
@@ -0,0 +1,11 @@
+#pragma once
+
+namespace floormat::fs {
+
+[[nodiscard]] bool file_exists(StringView name);
+
+} // namespace floormat::fs
+
+#ifndef fm_FILENAME_MAX
+#define fm_FILENAME_MAX (260)
+#endif