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_devtype sd_device_get_devname sd_device_get_devnum sd_device_get_ifindex sd_device_get_driver sd_device_get_diskseq 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_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

## 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_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`.

## 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.

## See Also

systemd 1