'\" t
.TH "SD_MACHINE_GET_CLASS" "3" "" "systemd 255" "sd_machine_get_class"
.\" -----------------------------------------------------------------
.\" * Define some portability stuff
.\" -----------------------------------------------------------------
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.\" http://bugs.debian.org/507673
.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\" -----------------------------------------------------------------
.\" * set default formatting
.\" -----------------------------------------------------------------
.\" disable hyphenation
.nh
.\" disable justification (adjust text to left margin only)
.ad l
.\" -----------------------------------------------------------------
.\" * MAIN CONTENT STARTS HERE *
.\" -----------------------------------------------------------------
.SH "NAME"
sd_machine_get_class, sd_machine_get_ifindices \- Determine the class and network interface indices of a locally running virtual machine or container
.SH "SYNOPSIS"
.sp
.ft B
.nf
#include <systemd/sd\-login\&.h>
.fi
.ft
.HP \w'int\ sd_machine_get_class('u
.BI "int sd_machine_get_class(const\ char*\ " "machine" ", char\ **" "class" ");"
.HP \w'int\ sd_machine_get_ifindices('u
.BI "int sd_machine_get_ifindices(const\ char*\ " "machine" ", int\ **" "ret_ifindices" ");"
.SH "DESCRIPTION"
.PP
\fBsd_machine_get_class()\fR
may be used to determine the class of a locally running virtual machine or container that is registered with
\fBsystemd-machined.service\fR(8)\&. The string returned is either
"vm"
or
"container"\&. The returned string needs to be freed with the libc
\fBfree\fR(3)
call after use\&.
.PP
\fBsd_machine_get_ifindices()\fR
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
\fBsystemd-machined.service\fR(8)\&. The output parameter
\fIret_ifindices\fR
may be passed as
\fBNULL\fR
when the output value is not needed\&. The returned array needs to be freed with the libc
\fBfree\fR(3)
call after use\&.
.SH "RETURN VALUE"
.PP
On success, these functions return a non\-negative integer\&.
\fBsd_machine_get_ifindices()\fR
returns the number of the relevant network interfaces\&. On failure, these calls return a negative errno\-style error code\&.
.SS "Errors"
.PP
Returned errors may indicate the following problems:
.PP
\fB\-ENXIO\fR
.RS 4
The specified machine does not exist or is currently not running\&.
.RE
.PP
\fB\-EINVAL\fR
.RS 4
An input parameter was invalid (out of range, or
\fBNULL\fR, where that is not accepted)\&.
.RE
.PP
\fB\-ENOMEM\fR
.RS 4
Memory allocation failed\&.
.RE
.SH "NOTES"
.PP
Functions described here are available as a shared library, which can be compiled against and linked to with the
\fBlibsystemd\fR\ \&\fBpkg-config\fR(1)
file\&.
.PP
The code described here uses
\fBgetenv\fR(3), which is declared to be not multi\-thread\-safe\&. This means that the code calling the functions described here must not call
\fBsetenv\fR(3)
from a parallel thread\&. It is recommended to only do calls to
\fBsetenv()\fR
from an early phase of the program when no other threads have been started\&.
.SH "HISTORY"
.PP
\fBsd_machine_get_class()\fR
and
\fBsd_machine_get_ifindices()\fR
were added in version 217\&.
.SH "SEE ALSO"
.PP
\fBsystemd\fR(1),
\fBsd-login\fR(3),
\fBsystemd-machined.service\fR(8),
\fBsd_pid_get_machine_name\fR(3)