hosts(5) [ultrix man page]

hosts(5)							File Formats Manual							  hosts(5)

Name
       hosts - host name file

Description
       The  file  is  an  ASCII file that contains information about the known hosts on the DARPA Internet.  For each host a single line should be
       present with the following information:

       Internet address
       Official host name
       Aliases

       Each name is separated from the next by a new line.  Items are separated by any number of blanks or tab	characters.   A  number  sign  (#)
       indicates the beginning of a comment; characters up to the end of the line are not interpreted by routines that search the file.  This file
       is normally created from the official host data base maintained at the Network Information Control Center (NIC), though local  changes  may
       be required to bring it up to date regarding unofficial aliases or unknown hosts.

       Host  addresses	are  specified	in  the  conventional  dot (.) notation using the inet_addr routine from the Internet address manipulation
       library, Host names can contain any printable character other than a field delimiter, newline, or comment character.

       The database may be distributed in a network by a naming service, such as Yellow Pages or BIND/Hesiod.  See the Guide to the  Yellow  Pages
       Service or the Guide to the BIND/Hesiod Service for setup information.

Files
See Also
       gethostent(3n)
       Guide to the BIND/Hesiod Service
       Guide to the Yellow Pages Service

																	  hosts(5)

gethostent(3n)															    gethostent(3n)

Name
       gethostent, gethostbyaddr, gethostbyname, sethostent, endhostent - get hosts entry

Syntax
       #include <netdb.h>

       struct hostent *gethostent()

       struct hostent *gethostbyname(name)
       char *name;

       struct hostent *gethostbyaddr(addr, len, type)
       char *addr; int len, type;

       void sethostent(stayopen)
       int stayopen;

       void endhostent()

Description
       The  and  subroutines  return  a  pointer to an object with the following structure containing the broken-out fields reflecting information
       obtained from the database.
       struct	hostent {
		char   *h_name;       /* official name of host */
		char   **h_aliases;   /* alias list */
		int    h_addrtype;    /* address type */
		int    h_length;      /* length of address */
		char   **h_addr_list; /* list of addresses from name server */
       #define	h_addr h_addr_list[0] /* address for backward compatibility */
       };

       The members of this structure are:

       h_name	   Official name of the host.

       h_aliases   A zero terminated array of alternate names for the host.

       h_addrtype  The type of address being returned; currently always AF_INET.

       h_length    The length, in bytes, of the address.

       h_addr	   A pointer to the network address for the host.  Host addresses are returned in network byte order.

       If the stayopen flag on a subroutine is NULL, the hosts database is opened.  Otherwise the has the effect of rewinding the  database.   The
       may be called to close the database when processing is complete.

       The  subroutine	simply	reads  the  next line while and search until a matching name, or addr, len, type is found (or until EOF is encoun-
       tered).	The subroutine keeps a pointer in the database, allowing successive calls to be used to search the entire file.

       The and subroutines query the database.

       A call to must be made before a loop using in order to perform initialization and an must be used after the loop.  Both and make  calls	to
       and

Restrictions
       All  information  is  contained	in a static area so it must be copied if it is to be saved.  Only the Internet address format is currently
       understood.

       If YP is running, does not return the entries in any particular order.  See the Guide to the Yellow Pages Service for setup information.

       The database may also be distributed via the BIND/Hesiod naming service.  See the Guide to the BIND/Hesiod Service for more information.

Return Values
       Null pointer(0) returned on EOF or error.

Files
See Also
       hosts(5), svc.conf(5)
       Guide to the BIND/Hesiod Service
       Guide to the Yellow Pages Service

																    gethostent(3n)