Проект OpenNet: MAN di_init (3) Библиотечные вызовы (FreeBSD и Linux)

Интерактивная система просмотра системных руководств (man-ов)

di_init (3)

>> di_init (3) ( Solaris man: Библиотечные вызовы )

NAME

di_init, di_fini - create and destroy a snapshot of kernel device tree

SYNOPSIS

cc [ flag... ] file... -ldevinfo [ library... ]
#include <libdevinfo.h>

di_node_t di_init(const char *phys_path, uint_t flags);

void di_fini(di_node_t root);

PARAMETERS

flags

Snapshot content specification. The possible values can be a bitwise OR of at least one of the following:

DINFOSUBTREE

: Include subtree.

DINFOPROP

: Include properties.

DINFOMINOR

: Include minor node data.

DINFOCPYALL

: Include all of the above.

DINFOPATH

: Include multipath path node data.

DINFOLYR

: Include device layering data.

DINFOCPYONE

: Include only a single node without properties, minor nodes, or path nodes.

phys_path

: Physical path of the root device node of the snapshot. See di_devfs_path(3DEVINFO).

root

: Handle obtained by calling di_init().

DESCRIPTION

The di_init() function creates a snapshot of the kernel device tree and returns a handle of the root device node. The caller specifies the contents of the snapshot by providing flag and phys_path.

The di_fini() function destroys the snapshot of the kernel device tree and frees the associated memory. All handles associated with this snapshot become invalid after the call to di_fini().

RETURN VALUES

Upon success, di_init() returns a handle. Otherwise, DI_NODE_NIL is returned and errno is set to indicate the error.

ERRORS

The di_init() function can set errno to any error code that can also be set by open(2), ioctl(2) or mmap(2). The most common error codes include:

EACCES

: Insufficient privilege for accessing device configuration data.

ENXIO

: Either the device named by phys_path is not present in the system, or the devinfo(7D) driver is not installed properly.

EINVAL

: Either phys_path is incorrectly formed or the flags argument is invalid.

EXAMPLES

Example 1 Using the libdevinfo Interfaces To Print All Device Tree Node Names

The following is an example using the libdevinfo interfaces to print all device tree device node names:

/*
* Code to print all device tree device node names
*/

#include <stdio.h>
#include <libdevinfo.h>

int 
prt_nodename(di_node_t node, void *arg)
{
    printf("%s\n", di_node_name(node));
    return (DI_WALK_CONTINUE);
}

main()
{
    di_node_t root_node;
    if((root_node = di_init("/", DINFOSUBTREE)) == DI_NODE_NIL) {
          fprintf(stderr, "di_init() failed\n");
          exit(1);
    }
    di_walk_node(root_node, DI_WALK_CLDFIRST, NULL, prt_nodename);
    di_fini(root_node);
}

Example 2 Using the libdevinfo Interfaces To Print The Physical Path Of SCSI Disks

The following example uses the libdevinfo interfaces to print the physical path of SCSI disks:

/*
* Code to print physical path of scsi disks
*/

#include <stdio.h>
#include <libdevinfo.h>
#define DISK_DRIVER     "sd"    /* driver name */

void
prt_diskinfo(di_node_t node)
{
   int instance;
       char *phys_path;

   /*
    * If the device node exports no minor nodes,
    * there is no physical disk.
    */
    if (di_minor_next(node, DI_MINOR_NIL) == DI_MINOR_NIL) {
             return;
        }

        instance = di_instance(node);
        phys_path = di_devfs_path(node);
        printf("%s%d: %s\n", DISK_DRIVER, instance, phys_path);
        di_devfs_path_free(phys_path);
}

void
walk_disknodes(di_node_t node)
{
       node = di_drv_first_node(DISK_DRIVER, node);
       while (node != DI_NODE_NIL) {
            prt_diskinfo(node);
            node = di_drv_next_node(node);
       }
}

main()
{
   di_node_t root_node;
   if ((root_node = di_init("/", DINFOCPYALL)) == DI_NODE_NIL) {
       fprintf(stderr, "di_init() failed\n");
       exit(1);
   }
       walk_disknodes(root_node);
       di_fini(root_node);
}