---
name: "nng_pipe_id"
section: "3"
platform: "linux"
package: "libnng-dev"
version: "1.10.1-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/nng_pipe_id"
---

# nng\_pipe\_id(3)

return numeric pipe identifier

## NAME

nng\_pipe\_id - return numeric pipe identifier

## SYNOPSIS

```
#include <nng/nng.h>
int nng_pipe_id(nng_pipe p);
```

## DESCRIPTION

The `nng_pipe_id()` function returns a positive identifier for the pipe *p*, if it is valid. Otherwise it returns `-1`.

**Note**\

A pipe is considered valid if it was ever created by the socket. Pipes that are allocated on the stack or statically should be initialized with the macro `NNG_PIPE_INITIALIZER` to ensure that they cannot be confused with a valid pipe.

## RETURN VALUES

This function returns the positive value for the pipe identifier, or `-1` if the pipe is invalid.

## ERRORS

None.

## SEE ALSO

[nng\_pipe(5)](/nng_pipe/5.md), [nng(7)](/nng/7.md)