Content-type: text/html Man page of netdb.h

netdb.h

Section: Headers (3HEAD)
Updated: 10 Sep 2004
Index Return to Main Contents
 

NAME

netdb.h, netdb - definitions for network database operations  

SYNOPSIS

#include <netdb.h> 
 

DESCRIPTION

The <netdb.h> header defines the type in_port_t and the type in_addr_t as described in in.h(3HEAD).

The <netdb.h> header defines the hostent structure that includes the following members:

char *h_name         /* official name of the host */
char **h_aliases     /* pointer to an array of pointers to alternative */
                     /* host names, terminated by a null pointer */
int  h_addrtype      /* address type */
int  h_length        /* length, in bytes, of the address */
char **h_addr_list   /* pointer to an array of pointers to network addresses */
                     /* (in network byte order) for the host, terminated by a */
                     /* null pointer */

The <netdb.h> header defines the netent structure that includes the following members:

char      *n_name         /* official, fully-qualified (including the domain) name */
                          /* of the network */
char      **n_aliases     /* pointer to an array of pointers to alternative */
                          /* network names, terminated by a null pointer */
int       n_addrtype      /* the address type of the network */
in_addr_t n_net           /* the network number, in host byte order */

The <netdb.h> header defines the protoent structure that includes the following members:

char *p_name         /* official name of the protocol */
char **p_aliases     /* pointer to an array of pointers to alternative */
                     /* protocol names, terminated by a null pointer */
int  p_proto         /* protocol number */

The <netdb.h> header defines the servent structure that includes the following members:


char *s_name         /* fficial name of the service */
char **s_aliases     /* pointer to an array of pointers to alternative */
                     /* service names, terminated by a null pointer */
int  s_port          /* port number at which the service resides, */
                     /* in network byte order */
char *s_proto        /* name of the protocol to use when */
                     /* contacting the service */

The <netdb.h> header defines the macro IPPORT_RESERVED with the value of the highest reserved Internet port number.

The <netdb.h> header provides a declaration for h_errno:

extern int h_errno;

The <netdb.h> header defines the following macros for use as error values for gethostbyaddr() and gethostbyname():

HOST_NOT_FOUNDNO_DATA
NO_RECOVERYTRY_AGAIN

Inclusion of the <netdb.h> header may also make visible all symbols from in.h(3HEAD).  

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPEATTRIBUTE VALUE
Interface StabilityStandard

 

SEE ALSO

intro(3), endhostent(3NSL), endhostent(3XNET), endnetent(3SOCKET), endnetent(3XNET), endprotoent(3SOCKET), endprotoent(3XNET), endservent(3SOCKET), endservent(3XNET), in.h(3HEAD), attributes(5), standards(5)


 

Index

NAME
SYNOPSIS
DESCRIPTION
ATTRIBUTES
SEE ALSO

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Time: 02:37:12 GMT, October 02, 2010