curl/docs/libcurl/curl_pushheader_bynum.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

1.5 KiB

c SPDX-License-Identifier Title Section Source See-also
Copyright (C) Daniel Stenberg, <daniel.se>, et al. curl curl_pushheader_bynum 3 libcurl
CURLMOPT_PUSHFUNCTION (3)
curl_pushheader_byname (3)

NAME

curl_pushheader_bynum - get a push header by index

SYNOPSIS

#include <curl/curl.h>

char *curl_pushheader_bynum(struct curl_pushheaders *h, size_t num);

DESCRIPTION

This is a function that is only functional within a CURLMOPT_PUSHFUNCTION(3) callback. It makes no sense to try to use it elsewhere and it has no function then.

It returns the value for the header field at the given index num, for the incoming server push request or NULL. The data pointed to is freed by libcurl when this callback returns. The returned pointer points to a "name:value" string that gets freed when this callback returns.

EXAMPLE

/* output all the incoming push request headers */
static int push_cb(CURL *parent,
                   CURL *easy,
                   size_t num_headers,
                   struct curl_pushheaders *headers,
                   void *clientp)
{
  int i = 0;
  char *field;
  do {
     field = curl_pushheader_bynum(headers, i);
     if(field)
       fprintf(stderr, "Push header: %s\n", field);
     i++;
  } while(field);
  return CURL_PUSH_OK; /* permission granted */
}

int main(void)
{
  CURLM *multi = curl_multi_init();
  curl_multi_setopt(multi, CURLMOPT_PUSHFUNCTION, push_cb);
}

AVAILABILITY

Added in 7.44.0

RETURN VALUE

Returns a pointer to the header field content or NULL.