di_init(3devinfo)

1di_init(3DEVINFO)    Device Information Library Functions    di_init(3DEVINFO)
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NAME

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

9       cc [ flag... ] file... -ldevinfo [ library... ]
10       #include <libdevinfo.h>
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12       di_node_t di_init(const char *phys_path, uint_t flags);
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15       void di_fini(di_node_t root);
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PARAMETERS

19       flags        Snapshot content specification. The possible values can be
20                    a bitwise OR of at least one of the following:
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22                    DINFOSUBTREE    Include subtree.
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25                    DINFOPROP       Include properties.
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28                    DINFOMINOR      Include minor node data.
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31                    DINFOCPYALL     Include all of the above.
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34                    DINFOPATH       Include multipath path node data.
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37                    DINFOLYR        Include device layering data.
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40                    DINFOCPYONE     Include only a single node without proper‐
41                                    ties, minor nodes, or path nodes.
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45       phys_path    Physical path of the root device node of the snapshot. See
46                    di_devfs_path(3DEVINFO).
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49       root         Handle obtained by calling di_init().
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DESCRIPTION

53       The di_init() function creates a snapshot of the kernel device tree and
54       returns a handle of the root device node. The caller specifies the con‐
55       tents of the snapshot by providing flag and phys_path.
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58       The di_fini() function destroys the snapshot of the kernel device  tree
59       and  frees  the  associated  memory.  All  handles associated with this
60       snapshot become invalid after the call to di_fini().
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RETURN VALUES

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

67       The di_init() function can set errno to any error code that can also be
68       set by open(2), ioctl(2)  or  mmap(2).  The  most  common  error  codes
69       include:
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71       EACCES    Insufficient  privilege  for  accessing  device configuration
72                 data.
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75       ENXIO     Either the device named by phys_path is not  present  in  the
76                 system, or the devinfo(7D) driver is not installed properly.
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79       EINVAL    Either  phys_path is incorrectly formed or the flags argument
80                 is invalid.
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EXAMPLES

84       Example 1 Using the libdevinfo Interfaces To Print All Device Tree Node
85       Names
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87
88       The  following  is  an example using the libdevinfo interfaces to print
89       all device tree device node names:
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91
92         /*
93          * Code to print all device tree device node names
94          */
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96         #include <stdio.h>
97         #include <libdevinfo.h>
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99         int
100         prt_nodename(di_node_t node, void *arg)
101         {
102              printf("%s\n", di_node_name(node));
103              return (DI_WALK_CONTINUE);
104         }
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106         main()
107         {
108              di_node_t root_node;
109              if((root_node = di_init("/", DINFOSUBTREE)) == DI_NODE_NIL) {
110                    fprintf(stderr, "di_init() failed\n");
111                    exit(1);
112              }
113              di_walk_node(root_node, DI_WALK_CLDFIRST, NULL, prt_nodename);
114              di_fini(root_node);
115         }
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118       Example 2 Using the libdevinfo Interfaces To Print The Physical Path Of
119       SCSI Disks
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122       The following example uses the libdevinfo interfaces to print the phys‐
123       ical path of SCSI disks:
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126         /*
127          * Code to print physical path of scsi disks
128          */
129
130         #include <stdio.h>
131         #include <libdevinfo.h>
132         #define   DISK_DRIVER    "sd" /* driver name */
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134         void
135         prt_diskinfo(di_node_t node)
136         {
137             int instance;
138                 char *phys_path;
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140             /*
141              * If the device node exports no minor nodes,
142              * there is no physical disk.
143              */
144              if (di_minor_next(node, DI_MINOR_NIL) == DI_MINOR_NIL) {
145                       return;
146                  }
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148                  instance = di_instance(node);
149                  phys_path = di_devfs_path(node);
150                  printf("%s%d: %s\n", DISK_DRIVER, instance, phys_path);
151                  di_devfs_path_free(phys_path);
152         }
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154         void
155         walk_disknodes(di_node_t node)
156         {
157                 node = di_drv_first_node(DISK_DRIVER, node);
158                 while (node != DI_NODE_NIL) {
159                      prt_diskinfo(node);
160                      node = di_drv_next_node(node);
161                 }
162         }
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164         main()
165         {
166             di_node_t root_node;
167             if ((root_node = di_init("/", DINFOCPYALL)) == DI_NODE_NIL) {
168                 fprintf(stderr, "di_init() failed\n");
169                 exit(1);
170             }
171                 walk_disknodes(root_node);
172                 di_fini(root_node);
173         }
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ATTRIBUTES

177       See attributes(5)  for descriptions of the following attributes:
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182       ┌─────────────────────────────┬─────────────────────────────┐
183       │      ATTRIBUTE TYPE         │      ATTRIBUTE VALUE        │
184       ├─────────────────────────────┼─────────────────────────────┤
185       │Interface Stability          │Committed                    │
186       ├─────────────────────────────┼─────────────────────────────┤
187       │MT-Level                     │Safe                         │
188       └─────────────────────────────┴─────────────────────────────┘
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