LSNS(8)			     System Administration		       LSNS(8)

NAME
       lsns - list namespaces

SYNOPSIS
       lsns [options] [namespace]

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 available columns, use with --json or --raw to get output
	   in 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). 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.

AUTHORS
       Karel Zak <kzak@redhat.com>

SEE ALSO
       nsenter(1), unshare(1), clone(2), namespaces(7), ioctl_ns(2),
       ip-netns(8) scols-filter(5)

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/>.

util-linux 2.41.2		  2025-09-22			       LSNS(8)