socket_open

Syntax

native socket_open(const _hostname[], _port, _protocol = SOCKET_TCP, &_error, _flags = 0);

Usage

Node to connect to

Service to connect to

Connect via SOCKET_TCP or SOCKET_UDP

Set an error code here if anything goes wrong

Optional bit flags that change the behaviour of the function

Description

Connects to the given node and service via TCP/UDP.

Note

• There's 2 types of error reporting on this function that you can use.

• Default error codes:
  0 - No error
  1 - Error while creating socket
  2 - Couldn't resolve hostname
  3 - Couldn't connect

• New, more expressive libc error codes:
  https://www.gnu.org/software/libc/manual/html_node/Error-Codes.html
  https://github.com/torvalds/linux/blob/master/include/uapi/asm-generic/errno.h
  https://msdn.microsoft.com/en-us/library/ms740668.aspx

• The currently available bit flags are:
  - SOCK_NON_BLOCKING : if set, the socket will be on nonblocking mode
  - SOCK_LIBC_ERRORS : if set, the new libc errors will be seen on _error

• If no flags are set, the behaviour of the function will not be modified.

• Multiple flags may be set at the same time using the | operator.
  For example, SOCK_NON_BLOCKING|SOCK_LIBC_ERRORS will create a nonblocking socket with libc error codes.

• If you're creating a new nonblocking socket, _hostname should be numeric to avoid calling the
  name resolution server and potentially blocking the call.

• If the socket is a nonblocking one, the returned socket descriptor may be still connecting and
  further checks should be done with socket_is_writable() before trying to send data.

Return

A socket descriptor (a positive integer) on success
-1 on failure