---
name: "CURLMOPT_PIPELINING_SITE_BL"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLMOPT_PIPELINING_SITE_BL"
---

# CURLMOPT\_PIPELINING\_SITE\_BL(3)

pipelining host block list

## NAME

CURLMOPT\_PIPELINING\_SITE\_BL - pipelining host block list

## SYNOPSIS

```
#include <curl/curl.h>
CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_PIPELINING_SITE_BL,
                            char **hosts);
```

## DESCRIPTION

No function since pipelining was removed in 7.62.0.

Pass a **hosts** array of char \*, ending with a NULL entry. This is a list of sites that are blocked from pipelining, i.e sites that are known to not support HTTP pipelining. The array is copied by libcurl.

Pass a NULL pointer to clear the block list.

## DEFAULT

NULL, which means that there is no block list.

## PROTOCOLS

This functionality affects http only

## EXAMPLE

```
static const char *site_block_list[] =
{
  "www.haxx.se",
  "www.example.com:1234",
  NULL
};
int main(void)
{
  CURLM *m = curl_multi_init();
  curl_multi_setopt(m, CURLMOPT_PIPELINING_SITE_BL, site_block_list);
}
```

## AVAILABILITY

Added in curl 7.30.0

## RETURN VALUE

*[curl\_multi\_setopt(3)](/curl_multi_setopt/3.md)* returns a CURLMcode indicating success or error.

CURLM\_OK (0) means everything was OK, non-zero means an error occurred, see *[libcurl-errors(3)](/libcurl-errors/3.md)*.

## SEE ALSO

[**CURLMOPT\_PIPELINING**(3)](/CURLMOPT_PIPELINING/3.md), [**CURLMOPT\_PIPELINING\_SERVER\_BL**(3)](/CURLMOPT_PIPELINING_SERVER_BL/3.md)