sd_device_enumerator_get_device_first - Man Page

#include <systemd/sd-device​.h>

sd_device *sd_device_enumerator_get_device_first(sd_device_enumerator *enumerator);

sd_device *sd_device_enumerator_get_device_next(sd_device_enumerator *enumerator);

sd_device *sd_device_enumerator_get_subsystem_first(sd_device_enumerator *enumerator);

sd_device *sd_device_enumerator_get_subsystem_next(sd_device_enumerator *enumerator);

The sd_device_enumerator_get_device_first() function enumerates all matching devices under /sys/bus/SUBSYSTEM/devices/ and /sys/class/SUBSYSTEM/devices/, and returns a pointer to the first sd_device object​. If no devices are found, NULL is returned​.

The sd_device_enumerator_get_device_next() function returns the pointer to the next sd_device from the enumerator​. It should be called after sd_device_enumerator_get_device_first() or after a previous call to this function​. If no more devices are available, NULL is returned​.

The sd_device_enumerator_get_subsystem_first() function enumerates all matching subsystem devices in /sys/module/, /sys/bus/, and /sys/bus/SUBSYSTEM/drivers/ (such as /sys/bus/pci/drivers/)​. It returns a pointer to the first sd_device object​. If no devices are found NULL is returned​. Note that this does not enumerate devices provided by sd_device_enumerator_get_device_first/next()​. Hence, e​.g​. /sys/bus/pci/, /sys/bus/pci/drivers/ahci/ and so on are enumerated, but /sys/bus/pci/devices/0000:00:00​.0/ and so on are not​.

The sd_device_enumerator_get_subsystem_next() function returns the next subsystem device from the enumerator​. It should be called after sd_device_enumerator_get_subsystem_first() or after a previous call to this function​. If no more subsystem devices are available, NULL is returned​.

On success, these functions return a pointer to an sd_device object​. On failure or when no more devices are available, NULL is returned​. The returned pointers are owned by the enumerator and should not be freed by the caller​.

sd_device_enumerator_get_device_first(), sd_device_enumerator_get_device_next(), sd_device_enumerator_get_subsystem_first(), and sd_device_enumerator_get_subsystem_next() were introduced in systemd version 240​.

sd_device_enumerator_new(3), sd_device_enumerator_add_match_parent(3), sd_device_ref(3)

sd_device_enumerator_add_match_parent(3), systemd.directives(7), systemd.index(7).

The man pages sd_device_enumerator_get_device_next(3), sd_device_enumerator_get_subsystem_first(3) and sd_device_enumerator_get_subsystem_next(3) are aliases of sd_device_enumerator_get_device_first(3).