`sig val execv : string -> string array -> unit val execve : string -> string array -> string array -> unit val execvp : string -> string array -> unit val wait : unit -> int * Unix.process_status val waitpid : Unix.wait_flag list -> int -> int * Unix.process_status val system : string -> Unix.process_status val read : Unix.file_descr -> bytes -> int -> int -> int val write : Unix.file_descr -> bytes -> int -> int -> int val write_substring : Unix.file_descr -> string -> int -> int -> int val timed_read : Unix.file_descr -> bytes -> int -> int -> float -> int val timed_write : Unix.file_descr -> bytes -> int -> int -> float -> int val timed_write_substring : Unix.file_descr -> string -> int -> int -> float -> int val select : Unix.file_descr list -> Unix.file_descr list -> Unix.file_descr list -> float -> Unix.file_descr list * Unix.file_descr list * Unix.file_descr list val pipe : unit -> Unix.file_descr * Unix.file_descr val open_process_in : string -> Pervasives.in_channel val open_process_out : string -> Pervasives.out_channel val open_process : string -> Pervasives.in_channel * Pervasives.out_channel val sleep : int -> unit val socket : Unix.socket_domain -> Unix.socket_type -> int -> Unix.file_descr val accept : Unix.file_descr -> Unix.file_descr * Unix.sockaddr val connect : Unix.file_descr -> Unix.sockaddr -> unit val recv : Unix.file_descr -> bytes -> int -> int -> Unix.msg_flag list -> int val recvfrom : Unix.file_descr -> bytes -> int -> int -> Unix.msg_flag list -> int * Unix.sockaddr val send : Unix.file_descr -> bytes -> int -> int -> Unix.msg_flag list -> int val send_substring : Unix.file_descr -> string -> int -> int -> Unix.msg_flag list -> int val sendto : Unix.file_descr -> bytes -> int -> int -> Unix.msg_flag list -> Unix.sockaddr -> int val sendto_substring : Unix.file_descr -> string -> int -> int -> Unix.msg_flag list -> Unix.sockaddr -> int val open_connection : Unix.sockaddr -> Pervasives.in_channel * Pervasives.out_channel end`