Sys

`sig
val argv : string array
val executable_name : string
external file_exists : string -> bool = "sys_file_exists"
external remove : string -> unit = "sys_remove"
external rename : string -> string -> unit = "sys_rename"
external getenv : string -> string = "sys_getenv"
external command : string -> int = "sys_system_command"
external time : unit -> float = "sys_time"
external chdir : string -> unit = "sys_chdir"
external getcwd : unit -> string = "sys_getcwd"
external readdir : string -> string array = "sys_read_directory"
val interactive : bool Pervasives.ref
val os_type : string
val word_size : int
val max_string_length : int
val max_array_length : int
type signal_behavior =
Signal_default
| Signal_ignore
| Signal_handle of (int -> unit)
external signal : int -> Sys.signal_behavior -> Sys.signal_behavior
= "install_signal_handler"
val set_signal : int -> Sys.signal_behavior -> unit
val sigabrt : int
val sigalrm : int
val sigfpe : int
val sighup : int
val sigill : int
val sigint : int
val sigkill : int
val sigpipe : int
val sigquit : int
val sigsegv : int
val sigterm : int
val sigusr1 : int
val sigusr2 : int
val sigchld : int
val sigcont : int
val sigstop : int
val sigtstp : int
val sigttin : int
val sigttou : int
val sigvtalrm : int
val sigprof : int
exception Break
val catch_break : bool -> unit
val ocaml_version : string
end`