val at_fdcwd : Base.unit -> Posixat.Fd.t
val has_mkfifoat : Base.bool
val openat : dir:Posixat.Fd.t -> path:Base.string -> flags:Posixat.Open_flag.t Base.list -> perm:Posixat.File_perm.t -> Unix.file_descr
val faccessat : dir:Posixat.Fd.t -> path:Base.string -> mode:Posixat.Access_permission.t Base.list -> flags:Posixat.At_flag.t Base.list -> unit
val fchmodat : dir:Posixat.Fd.t -> path:Base.string -> perm:Posixat.File_perm.t -> flags:Posixat.At_flag.t Base.list -> unit
val fchownat : dir:Posixat.Fd.t -> path:Base.string -> uid:Base.int -> gid:Base.int -> flags:Posixat.At_flag.t Base.list -> unit
val mkdirat : dir:Posixat.Fd.t -> path:Base.string -> perm:Posixat.File_perm.t -> unit
val unlinkat : dir:Posixat.Fd.t -> path:Base.string -> flags:Posixat.At_flag.t Base.list -> unit
val mkfifoat : dir:Posixat.Fd.t -> path:Base.string -> perm:Posixat.File_perm.t -> unit
val linkat : olddir:Posixat.Fd.t -> oldpath:Base.string -> newdir:Posixat.Fd.t -> newpath:Base.string -> flags:Posixat.At_flag.t Base.list -> unit
val renameat : olddir:Posixat.Fd.t -> oldpath:Base.string -> newdir:Posixat.Fd.t -> newpath:Base.string -> unit
val symlinkat : oldpath:Base.string -> newdir:Posixat.Fd.t -> newpath:Base.string -> unit
val fstatat : dir:Posixat.Fd.t -> path:Base.string -> flags:Posixat.At_flag.t Base.list -> Unix.LargeFile.stats
val readlinkat : dir:Posixat.Fd.t -> path:Base.string -> string
val fdopendir : Posixat.Fd.t -> Unix.dir_handle