.\" generated by cd2nroff 0.1 from CURLINFO_HEADER_SIZE.md .TH CURLINFO_HEADER_SIZE 3 "2026-09-02" libcurl .SH NAME CURLINFO_HEADER_SIZE \- size of response headers .SH SYNOPSIS .nf #include CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_HEADER_SIZE, long *sizep); .fi .SH DESCRIPTION Pass a pointer to a long to receive the total size of all the headers received, represented in HTTP/1\-style header format. Measured in number of bytes. The total includes the size of any received headers suppressed by \fICURLOPT_SUPPRESS_CONNECT_HEADERS(3)\fP. The number of bytes transferred over the wire (or to the TLS backend) is different when using HTTP/2 or greater. .SH PROTOCOLS This functionality affects all supported protocols .SH EXAMPLE .nf int main(void) { CURL *curl = curl_easy_init(); if(curl) { CURLcode result; curl_easy_setopt(curl, CURLOPT_URL, "https://example.com"); result = curl_easy_perform(curl); if(result == CURLE_OK) { long size; result = curl_easy_getinfo(curl, CURLINFO_HEADER_SIZE, &size); if(result == CURLE_OK) printf("Header size: %ld bytes\\n", size); } curl_easy_cleanup(curl); } } .fi .SH AVAILABILITY Added in curl 7.4.1 .SH RETURN VALUE \fIcurl_easy_getinfo(3)\fP returns a CURLcode indicating success or error. CURLE_OK (0) means everything was OK, non\-zero means an error occurred, see \fIlibcurl\-errors(3)\fP. .SH SEE ALSO .BR CURLINFO_REQUEST_SIZE (3), .BR CURLINFO_SIZE_DOWNLOAD (3), .BR curl_easy_getinfo (3), .BR curl_easy_setopt (3)