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

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if_freenameindex (3)

>> if_freenameindex (3) ( FreeBSD man: Библиотечные вызовы )

if_freenameindex (3) ( POSIX man: Библиотечные вызовы )

BSD mandoc

NAME



if_nametoindex

 
if_indextoname

 
if_nameindex

 
if_freenameindex

 - provide mappings between interface names and indexes

SYNOPSIS

   #include <sys/types.h>
   #include <sys/socket.h>
   #include <net/if.h>
unsigned int if_nametoindex (const char *ifname);
char * if_indextoname (unsigned int ifindex char *ifname);
struct if_nameindex * if_nameindex (void);
void if_freenameindex (struct if_nameindex *ptr);

DESCRIPTION

The if_nametoindex ();
function maps the interface name specified in Fa ifname to its corresponding index. If the specified interface does not exist, it returns 0.

The if_indextoname ();
function maps the interface index specified in Fa ifindex to it corresponding name, which is copied into the buffer pointed to by Fa ifname , which must be of at least IFNAMSIZ bytes. This pointer is also the return value of the function. If there is no interface corresponding to the specified index, NULL is returned.

The if_nameindex ();
function returns an array of Vt if_nameindex structures, one structure per interface, as defined in the include file In net/if.h . The Vt if_nameindex structure contains at least the following entries:

    unsigned int   if_index;  /* 1, 2, ... */
    char          *if_name;   /* null terminated name: "le0", ... */

The end of the array of structures is indicated by a structure with an if_index of 0 and an if_name of NULL A NULL pointer is returned upon an error.

The if_freenameindex ();
function frees the dynamic memory that was allocated by if_nameindex (.);

RETURN VALUES

Upon successful completion, if_nametoindex ();
returns the index number of the interface. If the interface is not found, a value of 0 is returned and errno is set to Er ENXIO . A value of 0 is also returned if an error occurs while retrieving the list of interfaces via getifaddrs(3).

Upon successful completion, if_indextoname ();
returns Fa ifname . If the interface is not found, a NULL pointer is returned and errno is set to Er ENXIO . A NULL pointer is also returned if an error occurs while retrieving the list of interfaces via getifaddrs(3).

The if_nameindex ();
returns a NULL pointer if an error occurs while retrieving the list of interfaces via getifaddrs(3), or if sufficient memory cannot be allocated.