table of contents
- bookworm 7.88.1-10+deb12u12
- bookworm-backports 8.12.1-3~bpo12+1
- testing 8.13.0-1
- unstable 8.13.0-3
CURLOPT_ALTSVC(3) | curl_easy_setopt options | CURLOPT_ALTSVC(3) |
NAME¶
CURLOPT_ALTSVC - alt-svc cache file name
SYNOPSIS¶
#include <curl/curl.h> CURLcode curl_easy_setopt(CURL *handle, CURLOPT_ALTSVC, char *filename);
DESCRIPTION¶
Pass in a pointer to a filename to instruct libcurl to use that file as the Alt-Svc cache to read existing cache contents from and possibly also write it back to a after a transfer, unless CURLALTSVC_READONLYFILE is set in CURLOPT_ALTSVC_CTRL(3).
Specify a blank file name ("") to make libcurl not load from a file at all.
DEFAULT¶
NULL. The alt-svc cache is not read nor written to file.
PROTOCOLS¶
HTTPS
EXAMPLE¶
CURL *curl = curl_easy_init(); if(curl) {
curl_easy_setopt(curl, CURLOPT_ALTSVC_CTRL, CURLALTSVC_H1);
curl_easy_setopt(curl, CURLOPT_ALTSVC, "altsvc-cache.txt");
curl_easy_perform(curl); }
FILE FORMAT¶
A text based file with one line per alt-svc entry and each line consists of nine space-separated fields.
An example line could look like
h2 www.example 8443 h3 second.example 443 "20190808 06:18:37" 1
0
The fields of that line are:
- h2
- ALPN id for the source origin
- www.example
- Host name for the source origin
- 8443
- Port number for the source origin
- h3
- ALPN id for the destination host
- second.example
- Host name for the destination host
- 443
- Port number for the destination host
- 2019*
- Expiration date and time of this entry within double quotes. The date format is "YYYYMMDD HH:MM:SS" and the time zone is GMT.
- 1
- Boolean (1 or 0) if "persist" was set for this entry
- 0
- Integer priority value (not currently used)
AVAILABILITY¶
Added in 7.64.1
RETURN VALUE¶
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
SEE ALSO¶
CURLOPT_ALTSVC_CTRL(3), CURLOPT_CONNECT_TO(3), CURLOPT_RESOLVE(3), CURLOPT_COOKIEFILE(3),
January 2, 2023 | libcurl 7.88.1 |