UDEV_DEVICE_NEW_FROM_SYSPATH - Online Linux Manual PageSection : 3
Updated :
Source : systemd 250
Note : udev_device_new_from_syspath

NAMEudev_device_new_from_syspath, udev_device_new_from_devnum, udev_device_new_from_subsystem_sysname, udev_device_new_from_device_id, udev_device_new_from_environment, udev_device_ref, udev_device_unref − Create, acquire and release a udev device object

SYNOPSIS#include <libudev​.h>struct udev_device *udev_device_new_from_syspath(struct udev *udev, const char *syspath); struct udev_device *udev_device_new_from_devnum(struct udev *udev, char type, dev_t devnum); struct udev_device *udev_device_new_from_subsystem_sysname(struct udev *udev, const char *subsystem, const char *sysname); struct udev_device *udev_device_new_from_device_id(struct udev *udev, const char *id); struct udev_device *udev_device_new_from_environment(struct udev *udev); struct udev_device *udev_device_ref(struct udev_device *udev_device); struct udev_device *udev_device_unref(struct udev_device *udev_device);

DESCRIPTIONudev_device_new_from_syspath(), udev_device_new_from_devnum(), udev_device_new_from_subsystem_sysname(), udev_device_new_from_device_id(), and udev_device_new_from_environment() allocate a new udev device object and returns a pointer to it​. This object is opaque and must not be accessed by the caller via different means than functions provided by libudev​. Initially, the reference count of the device is 1​. You can acquire further references, and drop gained references via udev_device_ref() and udev_device_unref()​. Once the reference count hits 0, the device object is destroyed and freed​. udev_device_new_from_syspath(), udev_device_new_from_devnum(), udev_device_new_from_subsystem_sysname(), and udev_device_new_from_device_id() create the device object based on information found in /sys/, annotated with properties from the udev−internal device database​. A syspath is any subdirectory of /sys/, with the restriction that a subdirectory of /sys/devices (or a symlink to one) represents a real device and as such must contain a uevent file​. udev_device_new_from_devnum() takes a device type, which can be b for block devices or c for character devices, as well as a devnum (see makedev(3))​. udev_device_new_from_subsystem_sysname() looks up devices based on the provided subsystem and sysname (see udev_device_get_subsystem(3) and udev_device_get_sysname(3)) and udev_device_new_from_device_id() looks up devices based on the provided device ID, which is a special string in one of the following four forms: .it 1 an-trap
Table ​1. ​Device ID strings Example Explanation b8:2 block device major:minor c128:1 char device major:minor n3 network device ifindex +sound:card29 kernel driver core subsystem:device name
udev_device_new_from_environment() creates a device from the current environment (see environ(7))​. Each key−value pair is interpreted in the same way as if it was received in an uevent (see udev_monitor_receive_device(3))​. The keys DEVPATH, SUBSYSTEM, ACTION, and SEQNUM are mandatory​.

RETURN VALUEOn success, udev_device_new_from_syspath(), udev_device_new_from_devnum(), udev_device_new_from_subsystem_sysname(), udev_device_new_from_device_id() and udev_device_new_from_environment() return a pointer to the allocated udev device​. On failure, NULL is returned, and errno is set appropriately​. udev_device_ref() returns the argument that it was passed, unmodified​. udev_device_unref() always returns NULL​.

SEE ALSOudev_new(3), udev_device_get_syspath(3), udev_device_has_tag(3), udev_enumerate_new(3), udev_monitor_new_from_netlink(3), udev_list_entry(3), systemd(1),
0
Johanes Gumabo
Data Size   :   15,090 byte
man-udev_device_new_from_subsystem_sysname.3Build   :   2024-12-05, 20:55   :  
Visitor Screen   :   x
Visitor Counter ( page / site )   :   4 / 170,625
Visitor ID   :     :  
Visitor IP   :   18.119.235.107   :  
Visitor Provider   :   AMAZON-02   :  
Provider Position ( lat x lon )   :   39.962500 x -83.006100   :   x
Provider Accuracy Radius ( km )   :   1000   :  
Provider City   :   Columbus   :  
Provider Province   :   Ohio ,   :   ,
Provider Country   :   United States   :  
Provider Continent   :   North America   :  
Visitor Recorder   :   Version   :  
Visitor Recorder   :   Library   :  
Online Linux Manual Page   :   Version   :   Online Linux Manual Page - Fedora.40 - march=x86-64 - mtune=generic - 24.12.05
Online Linux Manual Page   :   Library   :   lib_c - 24.10.03 - march=x86-64 - mtune=generic - Fedora.40
Online Linux Manual Page   :   Library   :   lib_m - 24.10.03 - march=x86-64 - mtune=generic - Fedora.40
Data Base   :   Version   :   Online Linux Manual Page Database - 24.04.13 - march=x86-64 - mtune=generic - fedora-38
Data Base   :   Library   :   lib_c - 23.02.07 - march=x86-64 - mtune=generic - fedora.36

Very long time ago, I have the best tutor, Wenzel Svojanovsky . If someone knows the email address of Wenzel Svojanovsky , please send an email to johanes_gumabo@yahoo.co.id .
If error, please print screen and send to johanes_gumabo@yahoo.co.id
Under development. Support me via PayPal.

ERROR : Need New Coding :         (parse_manual_page_|249|udev_device_new_from_syspath.3|83|it|.it 1 an-trap )