# nsenter

## NAME



           nsenter - run program in different namespaces
    


## SYNOPSIS



           **nsenter**[options] [_program_ [_arguments_]]
    


## DESCRIPTION



           The **nsenter** command executes _program_ in the namespace(s) that are
           specified in the command-line options (described below). If
           _program_ is not given, then "${SHELL}" is run (default: _/bin/sh_).
    
           Enterable namespaces are:
    
           **mount namespace**
               Mounting and unmounting filesystems will not affect the rest
               of the system, except for filesystems which are explicitly
               marked as shared (with **mount --make-shared** ; see
               _/proc/self/mountinfo_ for the **shared** flag). For further
               details, see mount_namespaces(7) and the discussion of the
               **CLONE_NEWNS** flag in clone(2).
    
           **UTS namespace**
               Setting hostname or domainname will not affect the rest of the
               system. For further details, see uts_namespaces(7).
    
           **IPC namespace**
               The process will have an independent namespace for POSIX
               message queues as well as System V message queues, semaphore
               sets and shared memory segments. For further details, see
               ipc_namespaces(7).
    
           **network namespace**
               The process will have independent IPv4 and IPv6 stacks, IP
               routing tables, firewall rules, the _/proc/net_ and
               _/sys/class/net_ directory trees, sockets, etc. For further
               details, see network_namespaces(7).
    
           **PID namespace**
               Children will have a set of PID to process mappings separate
               from the **nsenter** process. **nsenter** will fork by default if
               changing the PID namespace, so that the new program and its
               children share the same PID namespace and are visible to each
               other. If **--no-fork** is used, the new program will be exec’ed
               without forking. For further details, see pid_namespaces(7).
    
           **user namespace**
               The process will have a distinct set of UIDs, GIDs and
               capabilities. For further details, see user_namespaces(7).
    
           **cgroup namespace**
               The process will have a virtualized view of _/proc/self/cgroup_ ,
               and new cgroup mounts will be rooted at the namespace cgroup
               root. For further details, see cgroup_namespaces(7).
    
           **time namespace**
               The process can have a distinct view of **CLOCK_MONOTONIC** and/or
               **CLOCK_BOOTTIME** which can be changed using
               _/proc/self/timens_offsets_. For further details, see
               time_namespaces(7).
    


## OPTIONS



           Various of the options below that relate to namespaces take an
           optional _file_ argument. This should be one of the _/proc/[pid]/ns/*_
           files described in namespaces(7), or the pathname of a bind mount
           that was created on one of those files.
    
           **-a** , **--all**
               Enter all namespaces of the target process by the default
               _/proc/ <pid>/ns/*_ namespace paths. The default paths to the
               target process namespaces may be overridden by
               namespace-specific options (e.g., **--all --mount=**_path_).
    
               The user namespace will be ignored if the same as the caller’s
               current user namespace. It prevents a caller that has dropped
               capabilities from regaining those capabilities via a call to
               setns(). See setns(2) for more details.
    
           **-t** , **--target** _PID_
               Specify a target process to get contexts from. The paths to
               the contexts specified by _pid_ are:
    
               _/proc/pid/ns/mnt_
                   the mount namespace
    
               _/proc/pid/ns/uts_
                   the UTS namespace
    
               _/proc/pid/ns/ipc_
                   the IPC namespace
    
               _/proc/pid/ns/net_
                   the network namespace
    
               _/proc/pid/ns/pid_
                   the PID namespace
    
               _/proc/pid/ns/user_
                   the user namespace
    
               _/proc/pid/ns/cgroup_
                   the cgroup namespace
    
               _/proc/pid/ns/time_
                   the time namespace
    
               _/proc/pid/root_
                   the root directory
    
               _/proc/pid/cwd_
                   the working directory respectively
    
           **-m** , **--mount**[**=**_file_]
               Enter the mount namespace. If no file is specified, enter the
               mount namespace of the target process. If _file_ is specified,
               enter the mount namespace specified by _file_.
    
           **-u** , **--uts**[**=**_file_]
               Enter the UTS namespace. If no file is specified, enter the
               UTS namespace of the target process. If _file_ is specified,
               enter the UTS namespace specified by _file_.
    
           **-i** , **--ipc**[**=**_file_]
               Enter the IPC namespace. If no file is specified, enter the
               IPC namespace of the target process. If _file_ is specified,
               enter the IPC namespace specified by _file_.
    
           **-n** , **--net**[**=**_file_]
               Enter the network namespace. If no file is specified, enter
               the network namespace of the target process. If _file_ is
               specified, enter the network namespace specified by _file_.
    
           **-N** , **--net-socket** _fd_
               Enter the network namespace of the target process’s socket. It
               requires **--target** process specified. Supported since Linux
               5.6.
    
           **-p** , **--pid**[**=**_file_]
               Enter the PID namespace. If no file is specified, enter the
               PID namespace of the target process. If _file_ is specified,
               enter the PID namespace specified by _file_.
    
           **-U** , **--user**[**=**_file_]
               Enter the user namespace. If no file is specified, enter the
               user namespace of the target process. If _file_ is specified,
               enter the user namespace specified by _file_. See also the
               **--setuid** and **--setgid** options.
    
           **--user-parent**
               Enter the parent user namespace. Parent user namespace will be
               acquired from any other enabled namespace. If combined with
               **--user** option the parent user namespace will be fetched from
               the user namespace and replace it.
    
           **-C** , **--cgroup**[**=**_file_]
               Enter the cgroup namespace. If no file is specified, enter the
               cgroup namespace of the target process. If _file_ is specified,
               enter the cgroup namespace specified by _file_.
    
           **-T** , **--time**[**=**_file_]
               Enter the time namespace. If no file is specified, enter the
               time namespace of the target process. If _file_ is specified,
               enter the time namespace specified by _file_.
    
           **-G** , **--setgid** _gid_
               Set the group ID which will be used in the entered namespace
               and drop supplementary groups. **nsenter** always sets GID for
               user namespaces, the default is 0. If the argument "follow" is
               specified the GID of the target process is used.
    
           **-S** , **--setuid** _uid_
               Set the user ID which will be used in the entered namespace.
               **nsenter** always sets UID for user namespaces, the default is 0.
               If the argument "follow" is specified the UID of the target
               process is used.
    
           **--keep-caps**
               When the **--user** option is given, ensure that capabilities
               granted in the user namespace are preserved in the child
               process.
    
           **--preserve-credentials**
               Don’t modify UID and GID when entering the user namespace. The
               default is to drop supplementary groups and set GID and UID to
               0.
    
           **-r** , **--root**[**=**_directory_]
               Set the root directory. If no directory is specified, set the
               root directory to the root directory of the target process. If
               directory is specified, set the root directory to the
               specified directory. The specified _directory_ is opened before
               switching to the requested namespaces.
    
           **-w** , **--wd**[**=**_directory_]
               Set the working directory. If no directory is specified, set
               the working directory to the working directory of the target
               process. If directory is specified, set the working directory
               to the specified directory. The specified _directory_ is opened
               before switching to the requested namespaces, which means the
               specified directory works as a "tunnel" to the current
               namespace. See also **--wdns**.
    
           **-W** , **--wdns**[**=**_directory_]
               Set the working directory. The _directory_ is opened after
               switching to the requested namespaces and after calling
               chroot(2). The options **--wd** and **--wdns** are mutually exclusive.
    
           **-e** , **--env**
               Pass environment variables from the target process to the new
               process being created. If this option is not provided, the
               environment variables will remain the same as in the current
               namespace.
    
           **-F** , **--no-fork**
               Do not fork before exec’ing the specified program. By default,
               when entering a PID namespace, **nsenter** calls **fork** before
               calling **exec** so that any children will also be in the newly
               entered PID namespace.
    
           **-Z** , **--follow-context**
               Set the SELinux security context used for executing a new
               process according to the already running process specified by
               **--target** PID. (The util-linux has to be compiled with SELinux
               support otherwise the option is unavailable.)
    
           **-c** , **--join-cgroup**
               Add the initiated process to the cgroup of the target process.
    
           **-h** , **--help**
               Display help text and exit.
    
           **-V** , **--version**
               Display version and exit.
    


## NOTES



           The **--user-parent** option requires Linux 4.9 or higher, older
           kernels will raise inappropriate ioctl for device error.
    


## AVAILABILITY



           The **nsenter** 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
           util-linux@vger.kernel.org. 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 man-pages@man7.org
    
    util-linux 2.42-start-521-ec46  2025-08-09                     _NSENTER_(1)
    


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