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Headersnetdb(3HEAD)


NAME

 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(3HEAD).

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

char*h_nameOfficial name of the host.
char**h_aliasesA pointer to an array of pointers to alternative host names, terminated by a null pointer.
inth_addrtypeAddress type.
inth_lengthThe length, in bytes, of the address.
char**h_addr_listA 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_nameOfficial, fully-qualified (including the domain) name of the network.
char**n_aliasesA pointer to an array of pointers to alternative network names, terminated by a null pointer.
intn_addrtypeThe address type of the network.
in_addr_tn_netThe network number, in host byte order.

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

char*p_nameOfficial name of the protocol.
char**p_aliasesA pointer to an array of pointers to alternative protocol names, terminated by a null pointer.
intp_protoThe protocol number.

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

char*s_nameOfficial name of the service.
char**s_aliasesA pointer to an array of pointers to alternative service names, terminated by a null pointer.
ints_portThe port number at which the service resides, in network byte order.
char*s_protoThe 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(3HEAD).

Default

 

For applications that do not require standard-conforming behavior (those that use the socket interfaces described in section 3N of the reference manual; see Intro(3) and standards(5)), the following are declared as functions and can also be defined as macros:

intendhostent(void);
intendnetent(void);
intendprotoent(void);
intendservent(void);
struct hostent*gethostbyaddr(const void *addr, int len, int type);
struct hostent*gethostbyname(const char *name);
struct hostent*gethostent(void);
struct netent*getnetbyaddr(long net, int type);
struct netent*getnetbyname(const char *name);
struct netent*getnetent(void);
struct protoent*getprotobyname(const char *name);
struct protoent*getprotobynumber(int proto);
struct protoent*getprotoent(void);
struct servent*getservbyname(const char *name, const char *proto);
struct servent*getservbyport(int port, const char *proto);
struct servent*getservent(void);
intsethostent(int stayopen);
intsetnetent(int stayopen);
intsetprotoent(int stayopen);
intsetservent(int stayopen);

Standard conforming

 

For applications that require standard-conforming behavior (those that use the socket interfaces described in section 3XN of the reference manual; see Intro(3) and standards(5)), the following are declared as functions and can also be defined as macros:

voidendhostent(void);
voidendnetent(void);
voidendprotoent(void);
voidendservent(void);
struct hostent*gethostbyaddr(const void *addr, size_t len, int type);
struct hostent*gethostbyname(const char *name);
struct hostent*gethostent(void);
struct netent*getnetbyaddr(in_addr_t net, int type);
struct netent*getnetbyname(const char *name);
struct netent*getnetent(void);
struct protoent*getprotobyname(const char *name);
struct protoent*getprotobynumber(int proto);
struct protoent*getprotoent(void);
struct servent*getservbyname(const char *name, const char *proto);
struct servent*getservbyport(int port, const char *proto);
struct servent*getservent(void);
voidsethostent(int stayopen);
voidsetnetent(int stayopen);
voidsetprotoent(int stayopen);
voidsetservent(int stayopen);

SEE ALSO

 

Intro(3), endhostent(3NSL), endhostent(3XNET), endnetent(3SOCKET), endnetent(3XNET), endprotoent(3SOCKET), endprotoent(3XNET), endservent(3SOCKET), endservent(3XNET), in(3HEAD), standards(5)


SunOS 5.9Go To TopLast Changed 13 Aug 1998

 
      
      
Copyright 2002 Sun Microsystems, Inc. All rights reserved. Use is subject to license terms.