---
name: "CURLMOPT_PIPELINING_SERVER_BL"
section: "3"
platform: "macos"
package: "curl"
version: "166.0.0.0.1"
release: "macOS 26.5"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLMOPT_PIPELINING_SERVER_BL"
---

# CURLMOPT\_PIPELINING\_SERVER\_BL(3)

pipelining server block list

## NAME

CURLMOPT\_PIPELINING\_SERVER\_BL - pipelining server block list

## SYNOPSIS

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

## DESCRIPTION

No function since pipelining was removed in 7.62.0.

Pass a **servers** array of char \*, ending with a NULL entry. This is a list of server types prefixes (in the Server: HTTP header) that are blocked from pipelining, i.e server types that are known to not support HTTP pipelining. The array is copied by libcurl.

Note that the comparison matches if the Server: header begins with the string in the block list, i.e "Server: Ninja 1.2.3" and "Server: Ninja 1.4.0" can both be blocked by having "Ninja" in the list.

Pass a NULL pointer to clear the block list.

## DEFAULT

The default value is NULL, which means that there is no block list.

## PROTOCOLS

## EXAMPLE

```
static char *server_block_list[] =
{
  "Microsoft-IIS/6.0",
  "nginx/0.8.54",
  NULL
};
int main(void)
{
  CURLM *m = curl_multi_init();
  curl_multi_setopt(m, CURLMOPT_PIPELINING_SERVER_BL, server_block_list);
}
```

## AVAILABILITY

Added in 7.30.0

## RETURN VALUE

Returns CURLM\_OK if the option is supported, and CURLM\_UNKNOWN\_OPTION if not.

## SEE ALSO

[**CURLMOPT\_PIPELINING**(3)](/CURLMOPT_PIPELINING/3.md), [**CURLMOPT\_PIPELINING\_SITE\_BL**(3)](/CURLMOPT_PIPELINING_SITE_BL/3.md)