ENDNETENT(3P)                                       POSIX Programmer's Manual                                      ENDNETENT(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

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 mem-
       bers 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 overwrit-
       ten 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, Copy-
       right (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.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                 ENDNETENT(3P)