Stdio.In_channel
An input channel for doing blocking reads from input sources like files and sockets.
Note that an In_channel.t
is a custom block with a finalizer, and so is allocated directly to the major heap. Creating a lot of in_channels can result in many major collections and poor performance.
Note that this is simply another interface on the in_channel
type in the OCaml standard library.
type t = in_channel
include Base.Equal.S with type t := t
val equal : t Base.Equal.equal
val stdin : t
Channels are opened in binary mode iff binary
is true. This only has an effect on Windows.
val create : ?binary:Base.bool -> Base.string -> t
val with_file : ?binary:Base.bool -> Base.string -> f:(t -> 'a) -> 'a
with_file ~f fname
executes ~f
on the open channel from fname
, and closes it afterwards.
close t
closes t
, or does nothing if t
is already closed, and may raise an exception.
val input : t -> buf:Base.bytes -> pos:Base.int -> len:Base.int -> Base.int
val really_input :
t ->
buf:Base.bytes ->
pos:Base.int ->
len:Base.int ->
Base.unit Base.option
val really_input_exn :
t ->
buf:Base.bytes ->
pos:Base.int ->
len:Base.int ->
Base.unit
Same as Pervasives.really_input
, for backwards compatibility
val input_char : t -> Base.char Base.option
Read one character from the given input channel. Return None
if there are no more characters to read.
val input_byte : t -> Base.int Base.option
Same as input_char
, but return the 8-bit integer representing the character. Return None
if an end of file was reached.
val input_binary_int : t -> Base.int Base.option
Read an integer encoded in binary format (4 bytes, big-endian) from the given input channel. See Pervasives.output_binary_int
. Return None
if an end of file was reached while reading the integer.
val unsafe_input_value : t -> _ Base.option
Ocaml's built-in marshal format
val input_buffer : t -> Base.Buffer.t -> len:Base.int -> Base.unit Base.option
input_buffer t buf ~len
reads at most len
characters from the input channel t
and stores them at the end of buffer buf
. Return None
if the channel contains fewer than len
characters. In this case, the characters are still added to the buffer, so as to avoid loss of data.
val input_all : t -> Base.string
val input_line : ?fix_win_eol:Base.bool -> t -> Base.string Base.option
input_line ?fix_win_eol t
reads a line from t
and returns it, without the newline ("\n") character at the end, and, if fix_win_eol
the trailing "\r\n" is dropped.
val input_line_exn : ?fix_win_eol:Base.bool -> t -> Base.string
val fold_lines :
?fix_win_eol:Base.bool ->
t ->
init:'a ->
f:('a -> Base.string -> 'a) ->
'a
fold_lines ?fix_win_eol t ~init ~f
folds over the lines read from t
using input_line
. Lines are provided to f
in the order they are found in the file.
val input_lines : ?fix_win_eol:Base.bool -> t -> Base.string Base.list
Completely reads an input channel and returns the results as a list of strings. Each line in one string.
val iter_lines :
?fix_win_eol:Base.bool ->
t ->
f:(Base.string -> Base.unit) ->
Base.unit
iter_lines ?fix_win_eol t ~f
applies f
to each line read from t
using input_line
.
val seek : t -> Base.int64 -> Base.unit
This works only for regular files. On files of other kinds, the behavior is unspecified.
val pos : t -> Base.int64
val length : t -> Base.int64
Return the size (number of characters) of the regular file on which the given channel is opened. If the channel is opened on a file that is not a regular file, the result is meaningless. The returned size does not take into account the end-of-line translations that can be performed when reading from a channel opened in text mode.
same as Pervasives.set_binary_mode_in
, only applicable for Windows or Cygwin, no-op otherwise
val read_lines : ?fix_win_eol:Base.bool -> Base.string -> Base.string Base.list
read_lines filename
reads the full contents of file and returns it as a list of lines, closing the file when it's done. It's the equivalent of with_file fname
~f:input_lines
val read_all : Base.string -> Base.string
read_all filename
reads the full contents of file and returns it as a single string, closing the file when it's done. It's the equivalent of with_file fname
~f:input_all