# sd_device_get_syspath

## NAME



           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
    


## SYNOPSIS



           **#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_**);**
    


## 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
           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".
    


## 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.
    
               Added in version 251.
    
           **-ENOENT**
               The requested field is not present in the device record.
    
               Added in version 251.
    


## NOTES



           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.
    


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