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GETNETENT(3)                  Linux Programmer's Manual                  GETNETENT(3)

NAME         top

       getnetent,  getnetbyname,  getnetbyaddr,  setnetent,  endnetent  - get network
       entry

SYNOPSIS         top

       #include <netdb.h>

       struct netent *getnetent(void);

       struct netent *getnetbyname(const char *name);

       struct netent *getnetbyaddr(uint32_t net, int type);

       void setnetent(int stayopen);

       void endnetent(void);

DESCRIPTION         top

       The getnetent() function reads the next entry from the networks database and
       returns a netent structure containing the broken-out fields from the entry.  A
       connection is opened to the database if necessary.

       The getnetbyname() function returns a netent structure for the entry from the
       database that matches the network name.

       The getnetbyaddr() function returns a netent structure for the entry from the
       database that matches the network number net of type type.  The net argument
       must be in host byte order.

       The setnetent() function opens a connection to the database, and sets the next
       entry to the first entry.  If stayopen is nonzero, then the connection to the
       database will not be closed between calls to one of the getnet*() functions.

       The endnetent() function closes the connection to the database.

       The netent structure is defined in <netdb.h> as follows:

           struct netent {
               char      *n_name;     /* official network name */
               char     **n_aliases;  /* alias list */
               int        n_addrtype; /* net address type */
               uint32_t   n_net;      /* network number */
           }

       The members of the netent structure are:

       n_name The official name of the network.

       n_aliases
              A NULL-terminated list of alternative names for the network.

       n_addrtype
              The type of the network number; always AF_INET.

       n_net  The network number in host byte order.

RETURN VALUE         top

       The getnetent(), getnetbyname() and getnetbyaddr() functions return a pointer
       to a statically allocated netent structure, or a NULL pointer if an error
       occurs or the end of the file is reached.

FILES         top

       /etc/networks
              networks database file

CONFORMING TO         top

       4.3BSD, POSIX.1-2001.

NOTES         top

       In glibc versions before 2.2, the net argument of getnetbyaddr() was of type
       long.

SEE ALSO         top

       getnetent_r(3), getprotoent(3), getservent(3)
       RFC 1101

COLOPHON         top

       This page is part of release 3.32 of the Linux man-pages project.  A
       description of the project, and information about reporting bugs, can be found
       at http://www.kernel.org/doc/man-pages/.

GNU                                   2008-08-19                         GETNETENT(3)

HTML rendering created 2010-12-03 by Michael Kerrisk, author of The Linux Programming Interface

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