trusty (3) setnetent.3posix.gz

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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>


       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 .