Module Out_channel = Core_kernel.Out_channel


type t = Pervasives.out_channel
val stdout : t
val stderr : t
type 'a with_create_args = ?binary:bool -> ?append:bool -> ?perm:int -> 'a
val create : (string -> t) with_create_args
val with_file : (string -> f:(t -> 'a) -> 'a) with_create_args
val close : t -> unit

close t flushes and closes t, and may raise an exception. close returns () and does not raise if t is already closed. close raises an exception if the close() system call on the underlying file descriptor fails (i.e. returns -1), which would happen in the following cases:

EBADF -- this would happen if someone else did close() system call on the underlying fd, which I would think a rare event.

EINTR -- would happen if the system call was interrupted by a signal, which would be rare. Also, I think we should probably just catch EINTR and re-attempt the close. Unfortunately, we can't do that in OCaml because the OCaml library marks the out_channel as closed even if the close syscall fails, so a subsequent call close_out_channel will be a no-op. This should really be fixed in the OCaml library C code, having it restart the close() syscall on EINTR. I put a couple CRs in fixed_close_channel, our rework of OCaml's caml_ml_close_channel,

EIO -- I don't recall seeing this. I think it's rare.

See "man 2 close" for details.

val set_binary_mode : t -> bool -> unit
val flush : t -> unit
val output : t -> buf:string -> pos:int -> len:int -> unit
val output_string : t -> string -> unit
val output_char : t -> char -> unit
val output_byte : t -> int -> unit
val output_binary_int : t -> int -> unit
val output_value : t -> _ -> unit
val newline : t -> unit
val output_lines : t -> string list -> unit

Outputs a list of lines, each terminated by a newline character

val seek : t -> int64 -> unit
val pos : t -> int64
val length : t -> int64
val write_lines : string -> string list -> unit

The first argument of these is the file name to write to.

val write_all : string -> data:string -> unit