Socket object reference

This section provides details of the object’s properties and methods.

Socket object constructor:

[new] Socket ();

Creates and returns a new Socket object.


Socket object properties

connected Boolean When true, the connection is active. Read only.
encoding String Sets or retrieves the name of the encoding used to transmit data. Typical values are “ASCII,” “BINARY,” or “UTF-8.”
eof Boolean When true, the receive buffer is empty. Read only.
error String A message describing the most recent error. Setting this value clears any error message.
host String The name of the remote computer when a connection is established. If the connection is shut down or does not exist, the property contains the empty string. Read only.
timeout Number The timeout in seconds to be applied to read or write operations. Default is 10.

Socket object functions

close()

socketObj.close ();

Terminates the open connection. Deleting the object also closes the connection, but not until JavaScript garbage-collects the object.

The connection might stay open longer than you wish if you do not close it explicitly.

Returns true if the connection was closed, false on I/O errors.


listen()

socketObj.listen (port [, encoding]);

port Number. The TCP/IP port number to listen on. Valid port numbers are 1 to 65535. Typical values are 80 for a Web server, 23 for a Telnet server and so on.
encoding Optional. String. The encoding to be used for the connection. Typical values are “ASCII,” “binary,” or “UTF-8.” Default is “ASCII.”

Instructs the object to start listening for an incoming connection.

The call to open() and the call to listen() are mutually exclusive. Call one function or the other, not both.

Returns true on success.


open()

socketObj.open (host [, encoding]);

host String. The name or IP address of the remote computer, followed by a colon and the port number to connect to. The port number is required. Valid computer names are, for example, “www.adobe.com:80” or “192.150.14.12:80”.
encoding Optional. String. The encoding to be used for the connection. Typical values are “ASCII,” “binary,” or “UTF-8.” Default is “ASCII.”

Opens the connection for subsequent read/write operations.

The call to open() and the call to listen() are mutually exclusive. Call one function or the other, not both.

Returns true on success.


poll()

socketObj.poll ();

Checks a listening object for a new incoming connection. If a connection request was detected, the method returns a new Socket object that wraps the new connection. Use this connection object to communicate with the remote computer.

After use, close the connection and delete the JavaScript object. If no new connection request was detected, the method returns null.

Returns a Socket object or null.


read()

socketObj.read ([count]);

count Optional. Number. The number of characters to read; default is 0. If negative, the call is equivalent to readln()

Reads up to the specified number of characters from the connection, waiting if necessary. Ignores CR characters unless encoding is set to BINARY.

Returns a string that contains up to the number of characters that were supposed to be read, or the number of characters read before the connection closed or timed out.


readln()

socketObj.readln ();

Reads one line of text up to the next line feed. Line feeds are recognized as LF or CRLF pairs. CR characters are ignored.

Returns a string.


write()

socketObj.write (text[, text...]);

text String. Any number of string values. All arguments are concatenated to form the string to be written.

Concatenates all arguments into a single string and writes that string to the connection. CRLF sequences are converted to LFs unless encoding is set to BINARY.

Returns true on success.


writeln()

socketObj.writeln (text[, text...]);

text String. Any number of string values. All arguments are concatenated to form the string to be written.

Concatenates all arguments into a single string, appends a Line Feed character, and writes that string to the connection.

Returns true on success.