endhostent(3p) — Linux manual page

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

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

       endhostent, gethostent, sethostent — network host database
       functions

SYNOPSIS

       #include <netdb.h>

       void endhostent(void);
       struct hostent *gethostent(void);
       void sethostent(int stayopen);

DESCRIPTION

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

       Note:  In many cases this database is implemented by the Domain
              Name System, as documented in RFC 1034, RFC 1035, and
              RFC 1886.

       The sethostent() function shall open a connection to the database
       and set the next entry for retrieval to the first entry in the
       database. If the stayopen argument is non-zero, the connection
       shall not be closed by a call to gethostent(), and the
       implementation may maintain an open file descriptor.

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

       Entries shall be returned in hostent structures.

       The endhostent() function shall close the connection to the
       database, releasing any open file descriptor.

       These functions need not be thread-safe.

RETURN VALUE

       Upon successful completion, the gethostent() function shall
       return a pointer to a hostent 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.

       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
       gethostent().  The returned pointer, and pointers within the
       structure, might also be invalidated if the calling thread is
       terminated.

ERRORS

       No errors are defined for endhostent(), gethostent(), and
       sethostent().

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       endservent(3p)

       The Base Definitions volume of POSIX.1‐2017, netdb.h(0p)

COPYRIGHT

       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 .

IEEE/The Open Group               2017                    ENDHOSTENT(3P)

Pages that refer to this page: netdb.h(0p), endservent(3p), gethostent(3p), htonl(3p), inet_addr(3p), sethostent(3p)

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