curl/docs/libcurl/curl_ws_recv.md
Daniel Stenberg eefcc1bda4
docs: introduce "curldown" for libcurl man page format
curldown is this new file format for libcurl man pages. It is markdown
inspired with differences:

- Each file has a set of leading headers with meta-data
- Supports a small subset of markdown
- Uses .md file extensions for editors/IDE/GitHub to treat them nicely
- Generates man pages very similar to the previous ones
- Generates man pages that still convert nicely to HTML on the website
- Detects and highlights mentions of curl symbols automatically (when
  their man page section is specified)

tools:

- cd2nroff: converts from curldown to nroff man page
- nroff2cd: convert an (old) nroff man page to curldown
- cdall: convert many nroff pages to curldown versions
- cd2cd: verifies and updates a curldown to latest curldown

This setup generates .3 versions of all the curldown versions at build time.

CI:

Since the documentation is now technically markdown in the eyes of many
things, the CI runs many more tests and checks on this documentation,
including proselint, link checkers and tests that make sure we capitalize the
first letter after a period...

Closes #12730
2024-01-23 00:29:02 +01:00

74 lines
1.7 KiB
Markdown

---
c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
SPDX-License-Identifier: curl
Title: curl_ws_recv
Section: 3
Source: libcurl
See-also:
- curl_easy_getinfo (3)
- curl_easy_perform (3)
- curl_easy_setopt (3)
- curl_ws_send (3)
- libcurl-ws (3)
---
# NAME
curl_ws_recv - receive WebSocket data
# SYNOPSIS
~~~c
#include <curl/curl.h>
CURLcode curl_ws_recv(CURL *curl, void *buffer, size_t buflen,
size_t *recv, const struct curl_ws_frame **meta);
~~~
# DESCRIPTION
This function call is EXPERIMENTAL.
Retrieves as much as possible of a received WebSocket data fragment into the
**buffer**, but not more than **buflen** bytes. *recv* is set to the
number of bytes actually stored.
If there is more fragment data to deliver than what fits in the provided
*buffer*, libcurl returns a full buffer and the application needs to call
this function again to continue draining the buffer.
The *meta* pointer gets set to point to a *const struct curl_ws_frame*
that contains information about the received data. See the
curl_ws_meta(3) for details on that struct.
# EXAMPLE
~~~c
int main(void)
{
size_t rlen;
const struct curl_ws_frame *meta;
char buffer[256];
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res = curl_ws_recv(curl, buffer, sizeof(buffer), &rlen, &meta);
if(res)
printf("error: %s\n", curl_easy_strerror(res));
}
}
~~~
# AVAILABILITY
Added in 7.86.0.
# RETURN VALUE
Returns **CURLE_OK** if everything is okay, and a non-zero number for
errors. Returns **CURLE_GOT_NOTHING** if the associated connection is
closed.
Instead of blocking, the function returns **CURLE_AGAIN**. The correct
behavior is then to wait for the socket to signal readability before calling
this function again.