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(), gethostbyname(), or gethostbyaddr(), 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. Refer to
gethostbyaddr() for a definition of the hostent structure.
The endhostent() function shall close the connection to 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, 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.
ERRORS
No errors are defined for endhostent(), gethostent(), and sethostent().
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
The gethostent() function 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
endservent() , gethostbyaddr() , 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, 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 .