sd_device_get_syspath - Man Page

#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, const char **ret);

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 another 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"​.

On success, these calls return 0 or a positive integer​. On failure, they return a negative errno-style error code​.

Functions described here are available as a shared library, which can be compiled against and linked to with the libsystemd ​pkg-config(1) file​.

The code described here uses getenv(3), which is declared to be not multi-thread-safe​. This means that the code calling the functions described here must not call setenv(3) from a parallel thread​. It is recommended to only do calls to setenv() from an early phase of the program when no other threads have been started​.

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​.

systemd(1), sd-device(3)

sd-device(3), systemd.directives(7), systemd.index(7), udevadm(8).

The man pages sd_device_get_device_id(3), sd_device_get_devname(3), sd_device_get_devnum(3), sd_device_get_devpath(3), sd_device_get_devtype(3), sd_device_get_diskseq(3), sd_device_get_driver(3), sd_device_get_driver_subsystem(3), sd_device_get_ifindex(3), sd_device_get_subsystem(3), sd_device_get_sysname(3) and sd_device_get_sysnum(3) are aliases of sd_device_get_syspath(3).