os2: initial implementation for Darwin&BSDs, process API is only thing incomplete

core/os/os2/dir_posix.odin

@@ -0,0 +1,71 @@
+//+private
+//+build darwin, netbsd, freebsd, openbsd
+package os2
+
+import "base:runtime"
+
+import "core:sys/posix"
+
+@(private)
+_read_directory :: proc(f: ^File, n: int, allocator: runtime.Allocator) -> (files: []File_Info, err: Error) {
+	if f == nil || f.impl == nil {
+		err = .Invalid_File
+		return
+	}
+
+	n := n
+	if n == 0 {
+		return
+	}
+
+	impl := (^File_Impl)(f)
+
+	dir := posix.fdopendir(impl.fd)
+	if dir == nil {
+		err = _get_platform_error()
+		return
+	}
+	defer posix.closedir(dir)
+
+	dfiles: [dynamic]File_Info
+	dfiles.allocator = allocator
+	defer if err != nil {
+		file_info_slice_delete(dfiles[:], allocator)
+	}
+
+	for {
+		posix.set_errno(.NONE)
+		entry := posix.readdir(dir)
+		if entry == nil {
+			if errno := posix.errno(); errno != .NONE {
+				err = _get_platform_error()
+				return
+			} else {
+				break
+			}
+		}
+
+		cname := cstring(raw_data(entry.d_name[:]))
+		if cname == "." || cname == ".." {
+			continue
+		}
+
+		stat: posix.stat_t
+		if posix.fstatat(posix.dirfd(dir), cname, &stat, { .SYMLINK_NOFOLLOW }) != .OK {
+			err = _get_platform_error()
+			return
+		}
+
+		fullpath := concatenate({impl.name, "/", string(cname)}, allocator) or_return
+		fi := internal_stat(stat, fullpath)
+		append(&dfiles, fi) or_return
+
+		n -= 1
+		if n == 0 {
+			break
+		}
+	}
+
+	files = dfiles[:]
+	return
+}