curl/docs/libcurl/opts/CURLOPT_TRAILERDATA.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

60 lines
866 B
Markdown

---
c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
SPDX-License-Identifier: curl
Title: CURLOPT_TRAILERDATA
Section: 3
Source: libcurl
See-also:
- CURLOPT_TRAILERFUNCTION (3)
- CURLOPT_WRITEFUNCTION (3)
---
# NAME
CURLOPT_TRAILERDATA - pointer passed to trailing headers callback
# SYNOPSIS
~~~c
#include <curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TRAILERDATA, void *userdata);
~~~
# DESCRIPTION
Data pointer to be passed to the HTTP trailer callback function.
# DEFAULT
NULL
# PROTOCOLS
HTTP
# EXAMPLE
~~~c
struct MyData {
void *custom;
};
int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
struct MyData data;
curl_easy_setopt(curl, CURLOPT_TRAILERDATA, &data);
}
}
~~~
# AVAILABILITY
This option was added in curl 7.64.0 and is present if HTTP support is enabled
# RETURN VALUE
Returns CURLE_OK.