sd_device_get_syspath
systemd
sd_device_get_syspath
3
sd_device_get_syspath
sd_device_get_devpath
sd_device_get_sysname
sd_device_get_sysnum
sd_device_get_subsystem
sd_device_get_driver_subsystem
sd_device_get_devtype
sd_device_get_devname
sd_device_get_devnum
sd_device_get_ifindex
sd_device_get_driver
sd_device_get_diskseq
sd_device_get_device_id
Returns various fields of device objects
#include <systemd/sd-device.h>
int sd_device_get_syspath
sd_device *device
const char **ret
int sd_device_get_devpath
sd_device *device
const char **ret
int sd_device_get_sysname
sd_device *device
const char **ret
int sd_device_get_sysnum
sd_device *device
const char **ret
int sd_device_get_subsystem
sd_device *device
const char **ret
int sd_device_get_driver_subsystem
sd_device *device
const char **ret
int sd_device_get_devtype
sd_device *device
const char **ret
int sd_device_get_devname
sd_device *device
const char **ret
int sd_device_get_devnum
sd_device *device
dev_t *ret
int sd_device_get_ifindex
sd_device *device
int *ret
int sd_device_get_driver
sd_device *device
const char **ret
int sd_device_get_diskseq
sd_device *device
uint64_t *ret
int sd_device_get_device_id
sd_device *device
uint64_t *ret
Description
sd_device_get_syspath() returns the sysfs path of the specified device record,
including the /sys prefix. Example: /sys/devices/virtual/tty/tty7
sd_device_get_devpath() returns the sysfs path of the specified device record,
excluding the /sys prefix. Example: /devices/virtual/tty/tty7
sd_device_get_sysname() returns the sysfs name of the specified device record,
i.e. the last component of the sysfs path. Example: tty7 for the device
/sys/devices/virtual/tty/tty7
sd_device_get_sysnum() returns the sysfs device number of the specified device
record, i.e. the numeric suffix of the last component of the sysfs path. Example: 7
for the device /sys/devices/virtual/tty/tty7
sd_device_get_subsystem() returns the kernel subsystem of the specified device
record. This is a short string fitting into a filename, and thus does not contain a slash and cannot be
empty. Example: tty, block or net.
sd_device_get_driver_subsystem() returns the connected bus type of the devices
loaded by the specified driver device record. For example, when iwlwifi driver device
is specified, which is used by the wireless network interfaces connected to PCI bus, this function returns
pci. This function only succeeds when sd_device_get_subsystem()
returns drivers. Example: pci, i2c, or
hid.
sd_device_get_devtype() returns the device type of the specified device
record, if the subsystem manages multiple types of devices. Example: for devices of the
block subsystem this can be disk or partition
sd_device_get_devname() returns the device node path of the specified device
record if the device has a device node. Example: for /sys/devices/virtual/tty/tty7
the string /dev/tty7 is typically returned.
sd_device_get_devnum() returns the device node major/minor
(i.e. dev_t) of the specified device record if the device has a device node (i.e. the one
returned by sd_device_get_devname()). For devices belonging to the
block subsystem this refers to a block device node, in all other cases to a character
device node. Example: for the /sys/devices/virtual/tty/tty7 device this typically
returns the device number with major/minor 4:7.
sd_device_get_ifindex() returns the network interface index of the specified
device record, if the device encapsulates a network interface device, i.e. belongs to the
net subsystem. Example: the lo interface typically has interface
index 1.
sd_device_get_driver() returns the kernel driver name attached to the
device. Note that the driver field is set on the devices consumed by the driver, not on the device
created by it. Example: a PCI device /sys/bus/pci/devices/0000:00:1f.6 might be
attached to a driver e1000e.
sd_device_get_diskseq() returns the kernel disk sequence number of the block
device. This number monotonically increases whenever a backing medium of a block device changes without
the device name changing, and is relevant for block devices encapsulating devices with changing media
(e.g. floppy or CD-ROM), or loopback block devices. Only defined for block devices, i.e. those of
subsystem block.
sd_device_get_device_id() returns the short string that identifies the device
record. When the device ID obtained by the function for a specified device record is passed to
sd_device_new_from_device_id(), a new instance of the same device record will be
gained. When a block or character device is specified, which has corresponding device node, this returns
b or c, respectively, followed by the device node major and minor
numbers separated with a colon. Example: b259:1 or c10:121. When a
network interface device is specified, this returns n followed by the interface index,
which can be obtained by sd_device_get_ifindex(). Example: n1.
When a device in the driver subsystem is specified, this returns
+drivers: followed by its driver subsystem and sysfs name separated with a colon.
Example: +drivers:pci:iwlwifi for a driver device record whose driver subsystem is
pci and sysfs name is iwlwifi,
When an other type of device is specified, this function returns + followed by its
subsystem and sysfs name separated with a colon. Example: +acpi:ACPI0003:00,
+input:input16, or +pci:0000:00:1f.6.
Return Value
On success, these calls return 0 or a positive integer. On failure, they return a negative
errno-style error code.
Errors
Returned errors may indicate the following problems:
-EINVAL
A specified parameter is invalid.
-ENOENT
The requested field is not present in the device record.
History
sd_device_get_syspath(),
sd_device_get_devpath(),
sd_device_get_sysname(),
sd_device_get_sysnum(),
sd_device_get_subsystem(),
sd_device_get_devtype(),
sd_device_get_devname(),
sd_device_get_devnum(),
sd_device_get_ifindex(),
sd_device_get_driver(), and
sd_device_get_diskseq() were added in version 251.
sd_device_get_driver_subsystem() and
sd_device_get_device_id() were added in version 257.
See Also
systemd1