lsns(8) — Linux manual page

LSNS(8)                   System Administration                   LSNS(8)

NAME         top

       lsns - list namespaces

SYNOPSIS         top

       lsns [options] [namespace]

DESCRIPTION         top

       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         top

       -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). 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         top

       The lsns utility exits with one of the following values:

       0
           Success.

       1
           General error.

       2
           An ioctl was unknown to the kernel.

ENVIRONMENT         top

       LSNS_DEBUG=all
           enables lsns debug output.

AUTHORS         top

       Karel Zak <[email protected]>

SEE ALSO         top

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

REPORTING BUGS         top

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

AVAILABILITY         top

       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/>. This page is
       part of the util-linux (a random collection of Linux utilities)
       project. Information about the project can be found at 
       ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have a
       bug report for this manual page, send it to
       [email protected]. This page was obtained from the
       project's upstream Git repository
       ⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
       2025-08-11. (At that time, the date of the most recent commit that
       was found in the repository was 2025-08-05.) If you discover any
       rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page,
       or you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a
       mail to [email protected]

util-linux 2.42-start-521-ec46  2025-08-09                        LSNS(8)

Pages that refer to this page: namespaces(7)

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