lsns - list namespaces

       Karel Zak <kzak@redhat.com>

       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                                    2025-02-26                                            LSNS(8)

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.

LSNS_DEBUG=all
           enables lsns debug output.

       The lsns utility exits with one of the following values:

       0
           Success.

       1
           General error.

       2
           An ioctl was unknown to the kernel.

       lsns - list namespaces

-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, --outputlist
           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, --taskPID
           Display only the namespaces held by the process with this PID.

       -Q, --filterexpr
           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, --typetype
           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.

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

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

lsns [options] [namespace]