---
name: "mongoc_stream_writev"
section: "3"
platform: "linux"
package: "libmongoc-doc"
version: "1.30.4-1+deb13u3"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/mongoc_stream_writev"
---

# mongoc\_stream\_writev(3)

## SYNOPSIS

```
ssize_t
mongoc_stream_writev (mongoc_stream_t *stream,
                      mongoc_iovec_t *iov,
                      size_t iovcnt,
                      int32_t timeout_msec);
```

## PARAMETERS

- •

  **stream**: A *mongoc\_stream\_t*.

- •

  **iov**: A vector of *mongoc\_iovec\_t*.

- •

  **iovcnt**: The number of items in **iov**.

- •

  **timeout\_msec**: The number of milliseconds to block before indicating failure, or 0 for non-blocking. Negative values indicate the default timeout.

The **mongoc\_stream\_writev()** function shall perform a write to a *mongoc\_stream\_t*. It's modeled on the API and semantics of **writev()**, though the parameters map only loosely.

**WARNING:**

The "default timeout" indicated by a negative value is both unspecified and unrelated to the documented default values for **\*TimeoutMS** URI options. To specify a default timeout value for a **\*TimeoutMS** URI option, use the **MONGOC\_DEFAULT\_\*** constants defined in **mongoc-client.h**.

## RETURNS

The number of bytes written on success, or **-1** upon failure and **errno** is set.

## AUTHOR

MongoDB, Inc

## COPYRIGHT

2009-present, MongoDB, Inc.