plucky (3) endnetent.3posix.gz

Provided by: manpages-posix-dev_2017a-2_all bug

PROLOG
       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult 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 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 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.

       The  application  shall  not modify the structure to which the return value points, nor any storage areas
       pointed to by pointers within the structure. The returned pointer, and  pointers  within  the  structure,
       might  be  invalidated or the structure or the storage areas might be overwritten by a subsequent call to
       getnetbyaddr(), getnetbyname(), or getnetent().  The returned pointer, and pointers within the structure,
       might also be invalidated if the calling thread is terminated.


ERRORS
       No errors are defined.

       The following sections are informative.


EXAMPLES
       None.


APPLICATION USAGE
       None.


RATIONALE
       None.


FUTURE DIRECTIONS
       None.


SEE ALSO
       The Base Definitions volume of POSIX.1‐2017, <netdb.h>


       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group  Base
       Specifications  Issue  7, 2018 Edition, Copyright (C) 2018 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 .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .