sd_machine_get_class, sd_machine_get_ifindices — Determine the class and network interface indices of a locally running virtual machine or container
#include <systemd/sd-login.h>
| int sd_machine_get_class( | const char* machine, | 
| char **class ); | 
| int sd_machine_get_ifindices( | const char* machine, | 
| int **ret_ifindices ); | 
sd_machine_get_class() may be used to
    determine the class of a locally running virtual machine or
    container that is registered with
    systemd-machined.service(8).
    The string returned is either "vm" or
    "container". The returned string needs to be
    freed with the libc free(3)
    call after use.
sd_machine_get_ifindices() may be used to determine the numeric indices of the
    network interfaces on the host that are pointing towards the specified locally running virtual machine or
    container. The vm or container must be registered with
    systemd-machined.service(8).
    The output parameter ret_ifindices may be passed as NULL when
    the output value is not needed. The returned array needs to be freed with the libc free(3) call after
    use.
On success, these functions return a non-negative integer.
    sd_machine_get_ifindices() returns the number of the relevant network interfaces.
    On failure, these calls return a negative errno-style error code.
These APIs are implemented as a shared
  library, which can be compiled and linked to with the
  libsystemd pkg-config(1)
  file.