package stdio

  1. Overview
  2. Docs
package stdio
Legend:
Library
Module
Module type
Parameter
Class
Class type
val stdout : t
val stderr : t
type 'a with_create_args = ?binary:Base.Bool.t -> ?append:Base.Bool.t -> ?fail_if_exists:Base.Bool.t -> ?perm:Base.Int.t -> 'a
val create : (Base.String.t -> t) with_create_args
val with_file : (Base.String.t -> f:(t -> 'a) -> 'a) with_create_args
val close : t -> Base.Unit.t

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 -> Base.Bool.t -> Base.Unit.t
val flush : t -> Base.Unit.t
val output : t -> buf:Base.String.t -> pos:Base.Int.t -> len:Base.Int.t -> Base.Unit.t
val output_string : t -> Base.String.t -> Base.Unit.t
val output_char : t -> Base.Char.t -> Base.Unit.t
val output_byte : t -> Base.Int.t -> Base.Unit.t
val output_binary_int : t -> Base.Int.t -> Base.Unit.t
val output_buffer : t -> Base.Buffer.t -> Base.Unit.t
val output_value : t -> _ -> Base.Unit.t

OCaml's internal Marshal format

val newline : t -> Base.Unit.t
val output_lines : t -> Base.String.t Base.List.t -> Base.Unit.t

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

val fprintf : t -> ('a, t, Base.Unit.t) Pervasives.format -> 'a

Formatted printing to an out channel. This is the same as Printf.sprintf except that it outputs to t instead of returning a string. Similarly, the function arguments corresponding to conversions specifications such as %a or %t takes t as argument and must print to it instead of returning a string.

val printf : ('a, t, Base.Unit.t) Pervasives.format -> 'a

printf fmt is the same as fprintf stdout fmt

val eprintf : ('a, t, Base.Unit.t) Pervasives.format -> 'a

printf fmt is the same as fprintf stderr fmt

val kfprintf : (t -> 'a) -> t -> ('b, t, Base.Unit.t, 'a) Pervasives.format4 -> 'b

kfprintf k t fmt is the same as fprintf t fmt, but instead of returning immediately, passes the out channel to k at the end of printing.

val print_endline : Base.String.t -> Base.Unit.t

print_endline str outputs str to stdout followed by a newline then flushes stdout

val prerr_endline : Base.String.t -> Base.Unit.t

prerr_endline str outputs str to stderr followed by a newline then flushes stderr

val seek : t -> Base.Int64.t -> Base.Unit.t
val pos : t -> Base.Int64.t
val length : t -> Base.Int64.t

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

val write_all : Base.String.t -> data:Base.String.t -> Base.Unit.t