NAME

       endnetent, getnetbyaddr, getnetbyname, getnetent, setnetent - network database functions

SYNOPSIS

       #include <netdb.h>

       void endnetent(void);
       struct netent *getnetbyaddr(uint32_t net, int type);
       struct netent *getnetbyname(const char *name);
       struct netent *getnetent(void);
       void setnetent(int stayopen);

DESCRIPTION

       These functions shall retrieve information about networks. This information is considered to be stored in
       a  database  that  can  be  accessed  sequentially  or  randomly.  The implementation of this database is
       unspecified.

       The setnetent() function shall open and rewind the database.  If the stayopen argument is  non-zero,  the
       connection  to  the  net database shall not be closed after each call to getnetent() (either directly, or
       indirectly through one of the other getnet*() functions), and the implementation  may  maintain  an  open
       file descriptor to the database.

       The  getnetent()  function shall read the next entry of the database, opening and closing a connection to
       the database as necessary.

       The getnetbyaddr() function shall search the database from the beginning, and find the  first  entry  for
       which  the  address  family  specified  by  type matches the n_addrtype member and the network number net
       matches the n_net member, opening and closing a  connection  to  the  database  as  necessary.   The  net
       argument shall be the network number in host byte order.

       The  getnetbyname()  function  shall  search the database from the beginning and find the first entry for
       which the network name specified by name matches the n_name member, opening and closing a  connection  to
       the database as necessary.

       The  getnetbyaddr(),  getnetbyname(),  and  getnetent() functions shall each return a pointer to a netent
       structure, the members of which shall contain the fields of an entry in the network database.

       The endnetent() function shall close the database, releasing any open file descriptor.

       These functions need not be reentrant. A function that is not required to be reentrant is not required to
       be thread-safe.

RETURN VALUE

       Upon successful completion, getnetbyaddr(), getnetbyname(), and getnetent() shall return a pointer  to  a
       netent  structure  if  the  requested  entry was found, and a null pointer if the end of the database was
       reached or the requested entry was not found. Otherwise, a null pointer shall be returned.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       The getnetbyaddr(), getnetbyname(), and getnetent() functions may return pointers to static  data,  which
       may be overwritten by subsequent calls to any of these functions.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       The Base Definitions volume of IEEE Std 1003.1-2001, <netdb.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard  for  Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
       Inc and The Open Group. In the event of any discrepancy between this version and the  original  IEEE  and
       The  Open  Group  Standard,  the  original  IEEE and The Open Group Standard is the referee document. The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

IEEE/The Open Group                                   2003                                          ENDNETENT(P)