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58 lines
1.7 KiB
Markdown
58 lines
1.7 KiB
Markdown
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---
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title: "mg_connect_opt()"
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decl_name: "mg_connect_opt"
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symbol_kind: "func"
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signature: |
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struct mg_connection *mg_connect_opt(struct mg_mgr *mgr, const char *address,
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MG_CB(mg_event_handler_t handler,
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void *user_data);
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---
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Connects to a remote host.
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The `address` format is `[PROTO://]HOST:PORT`. `PROTO` could be `tcp` or
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`udp`. `HOST` could be an IP address,
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IPv6 address (if Mongoose is compiled with `-DMG_ENABLE_IPV6`) or a host
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name. If `HOST` is a name, Mongoose will resolve it asynchronously. Examples
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of valid addresses: `google.com:80`, `udp://1.2.3.4:53`, `10.0.0.1:443`,
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`[::1]:80`
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See the `mg_connect_opts` structure for a description of the optional
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parameters.
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Returns a new outbound connection or `NULL` on error.
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NOTE: The connection remains owned by the manager, do not free().
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NOTE: To enable IPv6 addresses `-DMG_ENABLE_IPV6` should be specified
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in the compilation flags.
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NOTE: The new connection will receive `MG_EV_CONNECT` as its first event
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which will report the connect success status.
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If the asynchronous resolution fails or the `connect()` syscall fails for
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whatever reason (e.g. with `ECONNREFUSED` or `ENETUNREACH`), then
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`MG_EV_CONNECT` event will report failure. Code example below:
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```c
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static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
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int connect_status;
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switch (ev) {
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case MG_EV_CONNECT:
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connect_status = * (int *) ev_data;
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if (connect_status == 0) {
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// Success
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} else {
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// Error
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printf("connect() error: %s\n", strerror(connect_status));
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}
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break;
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...
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}
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}
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...
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mg_connect(mgr, "my_site.com:80", ev_handler);
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```
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