socket_open

Синтаксис

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

Употреба

_hostname
Node to connect to
_port
Service to connect to
_protocol
Connect via SOCKET_TCP or SOCKET_UDP
_error
Set an error code here if anything goes wrong
_flags
Optional bit flags that change the behaviour of the function

Описание

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

Забележка

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

Забележка

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

Забележка

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

Забележка

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

Забележка

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

Забележка

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.

Забележка

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

Забележка

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.

Връщаща стойност

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