---
name: "lsns"
section: "8"
platform: "linux"
package: "util-linux"
version: "2.42.4-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/lsns"
---

# lsns(8)

list namespaces

## NAME

lsns - list namespaces

## SYNOPSIS

**lsns** \[options\] \[*namespace ID*\]

## DESCRIPTION

**lsns** lists information about all the currently accessible namespaces or about the given *namespace*. The *namespace* identifier is an inode number.

The default output is subject to change. So whenever possible, you should avoid using default outputs in your scripts. Always explicitly define expected output mode (**--tree** or **--list**) and columns by using the **--output** option together with a columns list in environments where a stable output is required.

The **NSFS** column, printed when **net** is specified for the **--type** option, is special; it uses multi-line cells. Use the option **--nowrap** to switch to ","-separated single-line representation.

Note that **lsns** reads information directly from the */proc* filesystem and for non-root users it may return incomplete information. The current */proc* filesystem may be unshared and affected by a PID namespace (see **unshare --mount-proc** for more details). **lsns** is not able to see persistent namespaces without processes where the namespace instance is held by a bind mount to /proc/*pid*/ns/*type*.

## OPTIONS

- **-H**, **--list-columns**

  List the columns that can be specified with the **--output** option. Can be used with **--json** or **--raw** to get the list in a machine-readable format.

- **-J**, **--json**

  Use JSON output format.

- **-l**, **--list**

  Use list output format.

- **-n**, **--noheadings**

  Do not print a header line.

- **-o**, **--output** *list*

  Specify which output columns to print. Use **--help** to get a list of all supported columns.

  The default list of columns may be extended if *list* is specified in the format **+***list* (e.g., **lsns -o +PATH**).

- **--output-all**

  Output all available columns.

- **-P**, **--persistent**

  Display only the namespaces without processes (aka persistent namespaces), created by bind mounting /proc/pid/ns/type files to a filesystem path.

- **-p**, **--task** *PID*

  Display only the namespaces held by the process with this *PID*.

- **-Q**, **--filter** *expr*

  Print only the namespaces that meet the conditions specified by the expr.

  This feature is EXPERIMENTAL. See also [**scols-filter**(5)](/scols-filter/5.md). For example exclude root as username, but print every namespaces more than one process belongs to:

```
lsns --filter 'USER != "root" and NPROCS > 1'
```

- **-r**, **--raw**

  Use the raw output format.

- **-t**, **--type** *type*

  Display the specified *type* of namespaces only. The supported types are **mnt**, **net**, **ipc**, **user**, **pid**, **uts**, **cgroup** and **time**. This option may be given more than once.

- **-u**, **--notruncate**

  Do not truncate text in columns.

- **-W**, **--nowrap**

  Do not use multi-line text in columns.

- **-T**, **--tree**\[**=***rel*\]

  Use tree-like output format. If **process** is given as *rel*, print process tree(s) in each name space. This is default when **--tree** is not specified. If **parent** is given, print tree(s) constructed by the parent/child relationship. If **owner** is given, print tree(s) constructed by the owner/owned relationship. **owner** is used as default when *rel* is omitted.

- **-h**, **--help**

  Display help text and exit.

- **-V**, **--version**

  Display version and exit.

## EXIT STATUS

The **lsns** utility exits with one of the following values:

**0**

Success.

**1**

General error.

**2**

An ioctl was unknown to the kernel.

## ENVIRONMENT

**LSNS\_DEBUG**=all

enables **lsns** debug output.

**LIBSMARTCOLS\_DEBUG**=all

enables libsmartcols debug output.

**LIBSMARTCOLS\_DEBUG\_PADDING**=on

use visible padding characters.

**LIBSMARTCOLS\_JSON**=compact\|lines

Controls JSON output format when using **--json**. Supported values are **compact** for JSON output with minimal whitespace, and **lines** for JSON Lines format (one JSON object per line). If unset or set to any other value, pretty-printed JSON is used.

## AUTHORS

*Karel Zak* \<kzak@redhat.com\>

## SEE ALSO

[**nsenter**(1)](/nsenter/1.md), [**unshare**(1)](/unshare/1.md), [**clone**(2)](/clone/2.md), [**namespaces**(7)](/namespaces/7.md), [**ioctl\_ns**(2)](/ioctl_ns/2.md), [**ip-netns**(8)](/ip-netns/8.md), [**scols-filter**(5)](/scols-filter/5.md)

## REPORTING BUGS

For bug reports, use the *issue tracker* \<https://github.com/util-linux/util-linux/issues\>.

## AVAILABILITY

The **lsns** command is part of the util-linux package which can be downloaded from *Linux Kernel Archive* \<https://www.kernel.org/pub/linux/utils/util-linux/\>.