lpd 1.2.1 · OCaml Package

Buffered sockets (Pervasive like functions for sockets working on all platforms).

This library is distributed under the terms of the GNU Lesser General Public License, with the special exception on linking as for the OCaml Library.

author Christophe Troestler

version 0.8

type in_channel

type out_channel

Abstract types for buffered sockets.

val in_channel_of_descr : Unix.file_descr -> in_channel

Create an input channel reading from the given descriptor.

val out_channel_of_descr : Unix.file_descr -> out_channel

Create an output channel writing on the given descriptor.

val descr_of_in_channel : in_channel -> Unix.file_descr

Return the descriptor corresponding to an input channel.

val descr_of_out_channel : out_channel -> Unix.file_descr

Return the descriptor corresponding to an output channel.

High-level network connection functions

val open_connection : Unix.sockaddr -> in_channel * out_channel

Connect to a server at the given address. Return a buffered socket. Can raise the same exceptions as Unix.open_connection.

val shutdown_connection : in_channel -> unit

``Shut down'' a connection established with Socket.open_connection; that is, transmit an end-of-file condition to the server reading on the other side of the connection. (You should flush the out_channels connected to the same socket if you want to make sure all data is transmitted.)

Output functions

val output : out_channel -> string -> int -> int -> unit

output oc buf pos len writes len characters from string buf, starting at offset pos, to the given buffered socket oc.

raises Invalid_argument
"Socket.output" if pos and len do not designate a valid substring of buf.

raises Sys_blocked_io
if we are in non-blocking mode and output would block.

val output_char : out_channel -> char -> unit

Write the character on the given buffered socket.

val output_string : out_channel -> string -> unit

Write the string on the given buffered socket.

val fprintf : out_channel -> ('a, unit, string, unit) Pervasives.format4 -> 'a

fprintf oc format arguments is like Printf.fprintf except that oc is a buffered socket.

val flush : out_channel -> unit

Flush the output buffer associated with the given buffered socket.

val close_out : out_channel -> unit

close_out oc closes the socket oc, flushing all buffered write operations. (This closes the underlying file descriptor as well.) Output functions raise a Sys_error exception when they are applied to a closed output channel, except close_out and flush which do nothing.

Input functions

val input : in_channel -> string -> int -> int -> int

input ic buf pos len reads up to len characters from the given socket ic, storing them in string buf, starting at character number pos. It returns the actual number of characters read, between 0 and len (inclusive).

A return value of 0 means that the end of file was reached.

raises Invalid_argument
"Socket.input" if pos and len do not designate a valid substring of buf.

raises Sys_blocked_io
if we are in non-blocking mode and input would block (no characters are then read).

val input_char : in_channel -> char

Read one character from the given input channel.

raises End_of_file
if there are no more characters to read.

raises Sys_blocked_io
if we are in non-blocking mode and input_char would block (no characters are then read).

val really_input : in_channel -> string -> int -> int -> unit

really_input ic buf pos len reads len characters from the buffered socket ic, storing them in string buf, starting at character number pos.

raises End_of_file
if the end of file is reached before len characters have been read.

raises Invalid_argument
"Socket.really_read" if pos and len do not designate a valid substring of buf.

raises Sys_blocked_io
if we are in non-blocking mode and really_input would block (the characters that may have been read are lost).

val input_line : in_channel -> string

input_line ic returns the next line from the socket ic without the final '\n'.

raises End_of_file
if the end of the file is reached.

raises Sys_blocked_io
if we are in non-blocking mode and input_line would block (the characters that may have been read are lost).

val input_till : char -> in_channel -> string -> int -> int -> int

input_till c ic buf pos len reads up to len characters different from c from the socket ic, storing them in string buf, starting at character number pos. The return value is the actual number of characters read (different from c), between 0 and len (inclusive). If c is encountered, the reading stops. c is left in the input stream; thus all further input_till commands will return 0.

raises End_of_file
if the end of the file is reached (i.e., there are no more characters to read). This is different from the return value being 0 -- the latter indicating that the first character in the stream is c.

raises Invalid_argument
"Socket.input_till" if pos and len do not designate a valid substring of buf.

raises Sys_blocked_io
if we are in non-blocking mode and input_till would block (no characters are then read).

val input_all_till : char -> in_channel -> string

input_all_till c ic returns the next chunk from the socket ic from the current position to the character c (excluded) or the end of the file. The character c is read and discarded.

raises End_of_file
if the end of the file is reached before any character can be read. (This is different from an empty string being returned which indicates that c is the first character in the input stream.)

raises Sys_blocked_io
if we are in non-blocking mode and input_all_till would block (the characters that may have been read are lost).

val close_in : in_channel -> unit

close_in ic closes the socket ic. (This closes the underlying file descriptor as well.) Input functions raise a Sys_error exception when they are applied to a closed input channel, except close_in, which does nothing when applied to an already closed channel.

Polling

val select : 
  in_channel list ->
  out_channel list ->
  float ->
  in_channel list * out_channel list

select inl outl t waits at most t seconds until some input/output operations become possible on some channels among inl and outl. A negative t means unbounded wait. The result is composed of two sets of channels: those ready for reading (first component) and those ready for writing (second component).

I/O objects

I/O objects for the channels respecting the conventions for IO-Classes. The objects only give another access to the channels and their methods can be interspersed with the above function calls.

class out_channel_obj : out_channel -> object ... end

class in_channel_obj : in_channel -> object ... end

package lpd

High-level network connection functions

Output functions

Input functions

Polling

I/O objects