PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

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

PROLOG         top

       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         top

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

SYNOPSIS         top

       #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         top

       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         top

       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().

ERRORS         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

       None.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       The Base Definitions volume of POSIX.1‐2008, netdb.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/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 .

IEEE/The Open Group                 2013                       ENDNETENT(3P)

Pages that refer to this page: netdb.h(0p)getnetbyaddr(3p)inet_addr(3p)setnetent(3p)