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 2025-02-26 LSNS(8)
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