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/*
* Generic WebSocket auxiliary functions
*
* Copyright (C) 2024 Runxi Yu <https://runxiyu.org>
* SPDX-License-Identifier: AGPL-3.0-or-later
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
/*
* The message format is a WebSocket message separated with spaces.
* The contents of each field could contain anything other than spaces,
* The first character of each argument cannot be a colon. As an exception, the
* last argument may contain spaces and the first character thereof may be a
* colon, if the argument is prefixed with a colon. The colon used for the
* prefix is not considered part of the content of the message. For example, in
*
* SQUISH POP :cat purr!!
*
* the first field is "SQUISH", the second field is "POP", and the third
* field is "cat purr!!".
*
* It is essentially an RFC 1459 IRC message without trailing CR-LF and
* without prefixes. See section 2.3.1 of RFC 1459 for an approximate
* BNF representation.
*
* The reason this was chosen instead of using protobuf etc. is that it
* is simple to parse without external libraries, and it also happens to
* be a format I'm very familiar with, having extensively worked with the
* IRC protocol.
*/
package main
import (
"context"
"fmt"
"github.com/coder/websocket"
)
func writeText(ctx context.Context, c *websocket.Conn, msg string) error {
err := c.Write(ctx, websocket.MessageText, []byte(msg))
if err != nil {
return fmt.Errorf("error writing to connection: %w", err)
}
return nil
}
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