1if_nametoindex(3SOCKET) Sockets Library Functions if_nametoindex(3SOCKET)
2
6 if_nametoindex, if_indextoname, if_nameindex, if_freenameindex - rou‐
7 tines to map Internet Protocol network interface names and interface
8 indexes
9
11 cc [ flag... ] file... -lsocket [ library... ]
12 #include <net/if.h>
13 unsigned int if_nametoindex(const char *ifname);
15 char *if_indextoname(unsigned int ifindex, char *ifname);
18 struct if_nameindex *if_nameindex(void)
21 void if_freenameindex(struct if_nameindex *ptr);
24
27 ifname interface name
28 ifindex interface index
31 ptr pointer returned by if_nameindex()
34
37 This API defines two functions that map between an Internet Protocol
38 network interface name and index, a third function that returns all the
39 interface names and indexes, and a fourth function to return the
40 dynamic memory allocated by the previous function.
41 Network interfaces are normally known by names such as eri0, sl1, ppp2,
44 and the like. The ifname argument must point to a buffer of at least
45 IF_NAMESIZE bytes into which the interface name corresponding to the
46 specified index is returned. IF_NAMESIZE is defined in <net/if.h> and
47 its value includes a terminating null byte at the end of the interface
48 name.
49 if_nametoindex() The if_nametoindex() function returns the inter‐
51 face index corresponding to the interface name
52 pointed to by the ifname pointer. If the speci‐
53 fied interface name does not exist, the return
54 value is 0, and errno is set to ENXIO. If there
55 was a system error, such as running out of mem‐
56 ory, the return value is 0 and errno is set to
57 the proper value, for example, ENOMEM.
58 if_indextoname() The if_indextoname() function maps an interface
61 index into its corresponding name. This pointer
62 is also the return value of the function. If
63 there is no interface corresponding to the speci‐
64 fied index, NULL is returned, and errno is set to
65 ENXIO, if there was a system error, such as run‐
66 ning out of memory, if_indextoname() returns NULL
67 and errno would be set to the proper value, for
68 example, ENOMEM.
69 if_nameindex() The if_nameindex() function returns an array of
72 if_nameindex structures, one structure per inter‐
73 face. The if_nameindex structure holds the infor‐
74 mation about a single interface and is defined
75 when the <net/if.h> header is included:
76 struct if_nameindex
78 unsigned int if_index; /* 1, 2, ... */
79 char *if_name; /* "net0", ... */
80 };
81 While any IPMP IP interfaces are returned by
83 if_nameindex(), the underlying IP interfaces that
84 comprise each IPMP group are not returned.
85 The end of the array of structures is indicated
87 by a structure with an if_index of 0 and an
88 if_name of NULL. The function returns a null
89 pointer upon an error and sets errno to the
90 appropriate value. The memory used for this array
91 of structures along with the interface names
92 pointed to by the if_name members is obtained
93 dynamically. This memory is freed by the
94 if_freenameindex() function.
95 if_freenameindex() The if_freenameindex() function frees the dynamic
98 memory that was allocated by if_nameindex(). The
99 argument to this function must be a pointer that
100 was returned by if_nameindex().
101
104 See attributes(5) for descriptions of the following attributes:
105 ┌─────────────────────────────┬─────────────────────────────┐
110 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
111 ├─────────────────────────────┼─────────────────────────────┤
112 │Availability │SUNWcsl (32-bit) │
113 │ │SUNWcslx (64-bit) │
114 ├─────────────────────────────┼─────────────────────────────┤
115 │MT-Level │MT-Safe │
116 └─────────────────────────────┴─────────────────────────────┘
117
119 ifconfig(1M), if_nametoindex(3XNET), attributes(5), if(7P)
120SunOS 5.11 28 Jan 2009 if_nametoindex(3SOCKET)