curl_pushheader_byname(3) Introduction to Library Functions

NAME

curl_pushheader_byname - get a push header by name

SYNOPSIS

#include <curl/curl.h>

char *curl_pushheader_byname(struct curl_pushheaders *h, const char *name);

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 given header field name (or NULL) for
the incoming server push request. This is a shortcut so that the
application does not have to loop through all headers to find the one
it is interested in. The data this function points to is freed when
this callback returns and, although not constrained by its type, may
not be altered. If more than one header field use the same name, this
returns only the first one.

PROTOCOLS

This functionality affects http only

EXAMPLE

#include <string.h> /* for strncmp */

static int push_cb(CURL *parent,
CURL *easy,
size_t num_headers,
struct curl_pushheaders *headers,
void *clientp)
{
char *headp;
int *transfers = (int *)clientp;
FILE *out;
headp = curl_pushheader_byname(headers, ":path");
if(headp && !strncmp(headp, "/push-", 6)) {
fprintf(stderr, "The PATH is %s\n", headp);

/* save the push here */
out = fopen("pushed-stream", "wb");

/* write to this file */
curl_easy_setopt(easy, CURLOPT_WRITEDATA, out);

(*transfers)++; /* one more */

return CURL_PUSH_OK;
}
return CURL_PUSH_DENY;
}

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

AVAILABILITY

Added in curl 7.44.0

RETURN VALUE

Returns a pointer to the header field content or NULL.

SEE ALSO

CURLMOPT_PUSHFUNCTION(3), curl_pushheader_bynum(3)

libcurl 2026-01-08 curl_pushheader_byname(3)