---
name: "vznnc"
section: "8"
platform: "linux"
package: "vzctl"
version: "4.9.4-6"
release: "Debian 10 (Buster)"
platforms: ["linux"]
url: "https://new.carta.tech/vznnc"
---

# vznnc(8)

run a program connected to a socket

## NAME

vznnc - run a program connected to a socket

## SYNOPSIS

**vznnc** { **-l** \| **-c** } **-p** *port* \[**-f** *fd*\] \[**--**\] *program* \[*arg* *...*\]

## DESCRIPTION

This "nano-netcat" utility can be used to either listen on or connect to a TCP port at localhost, and run a specified *program* with its stdin and stdout (or a specified file descriptor) connected to the socket.

## OPTIONS

- **-l**

  Listen on a specified TCP port at localhost.

- **-c**

  Connect to a specified TCP port at localhost.

- **-p** *port*

  Port number.

- **-f** *fd*

  File descriptor ID. If this option is not set, stdin and stdout are closed and are connected to the socket, otherwise they are left intact, and the specified *fd* is used.

- **--**

  This is a separator between **vznnc** own arguments and *program* arguments, so that latter won't be processed by **vznnc**. It is required in case there are any arguments to *program* that start with the dash (**-**) character, and is optional otherwise.

- *program* \[ *arg* *...* \]

  Program to run, with optional arguments.

## EXIT STATUS

Returns *program* exit status upon success, or one of the following codes in case of an error:

- 1

  Invalid usage

- 127

  Error executing *program*.

- 220

  Network-related error.

## EXAMPLES

To run receiving side of **ploop copy** command on a remote server, using openssh port forwarding:

```
 PORT=2345
 ssh -L localhost:$PORT:localhost:$PORT $REMOTE_SERVER \
	vznnc -l -p $PORT -- ploop copy -d $FILE -i0 -o1
```

To do the same, but with stdin and stdout intact, using file descriptor 5 for communication:

```
 ssh -L localhost:$PORT:localhost:$PORT $REMOTE_SERVER \
	vznnc -l -p $PORT -f 5 -- ploop copy -d $FILE -i5 -o5
```

## SEE ALSO

**nc**(3), **netcat**(3), **socat**(2).

## LICENSE

`Copyright (C) 2014, Parallels, Inc. Licensed under GNU GPL v2.`