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| Device Information Library Functions | di_init(3DEVINFO) |
| | di_init, di_fini - create and destroy a snapshot of kernel device tree |
SYNOPSIS
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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); |
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flags
- Snapshot content specification. The possible values can be a bitwise OR of the following:
-
DINFOSUBTREE
- Include subtree.
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DINFOPROP
- Include properties.
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DINFOMINOR
- Include minor data.
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DINFOCPYALL
- Include all of above.
If flags is 0, the snapshot contains only a single node without properties or minor nodes.
-
phys_path
- Physical path of the root node of the snapshot. See di_devfs_path(3DEVINFO).
-
root
- Handle obtained by calling di_init().
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The di_init() function creates a snapshot of the kernel device tree and returns a handle of the root 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().
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Upon success, di_init() returns a handle. Otherwise, DI_NODE_NIL is returned and errno is set to indicate the error.
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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:
-
EACCESS
- 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.
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| | Example 1. Using the libdevinfo Interfaces To Print All Device Tree Node Names
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The following is an example using the libdevinfo() interfaces to print all device tree node names:
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/*
* Code to print all device tree 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);
}
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Example 2. Using the libdevinfo Interfaces To Print The Physical Path Of SCSI Disks
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The following example uses the libdevinfo()interfaces to print the physical path of SCSI disks:
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/*
* 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);
}
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See attributes(5) for descriptions of the following attributes:
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
| Interface Stability | Evolving |
| MT-Level | Safe |
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