cap_get_nsowner - Linux
Overview
cap_get_nsowner retrieves the user namespace owner details for the specified process. It determines if the process is in a user namespace and, if so, which user is the owner of the namespace.
Syntax
cap_get_nsowner [--namespace-id PID/CGROUP/USERNS]
Options/Flags
- –namespace-id: Specifies the process, cgroup, or user namespace identifier to check. The default is the current process.
Examples
Get namespace owner for a process:
cap_get_nsowner --namespace-id PID
Get namespace owner for a user namespace:
cap_get_nsowner --namespace-id USERNS
Get namespace owner for a cgroup:
cap_get_nsowner --namespace-id CGROUP
Common Issues
- If the process is not in a user namespace, the command will return an error.
- If the user specified by
--namespace-id
does not exist, the command will also return an error.
Integration
cap_get_nsowner can be integrated with other commands to manage user namespaces effectively. For example:
# Check if a process is in a user namespace
if cap_get_nsowner --namespace-id PID >/dev/null 2>&1; then
echo "Process $PID is in a user namespace"
fi
Related Commands
- unshare – Creates a user namespace.
- usernamespaces – Linux kernel documentation on user namespaces.