curl/docs/libcurl/curl_pushheader_bynum.md
Daniel Stenberg b935fd4a07
docs: make each libcurl man specify protocol(s)
The mandatory header now has a mandatory list of protocols for which the
manpage is relevant.

Most man pages already has a "PROTOCOLS" section, but this introduces a
stricter way to specify the relevant protocols.

cd2nroff verifies that at least one protocol is mentioned (which can be
`*`).

This information is not used just yet, but A) the PROTOCOLS section can
now instead get generated and get a unified wording across all manpages
and B) this allows us to more reliably filter/search for protocol
specific manpages/options.

Closes #13166
2024-03-21 15:27:06 +01:00

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1.6 KiB
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---
c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
SPDX-License-Identifier: curl
Title: curl_pushheader_bynum
Section: 3
Source: libcurl
See-also:
- CURLMOPT_PUSHFUNCTION (3)
- curl_pushheader_byname (3)
Protocol:
- HTTP
---
# NAME
curl_pushheader_bynum - get a push header by index
# SYNOPSIS
~~~c
#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
~~~c
/* 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.