dn_expand(3) Library Functions Manual dn_expand(3)
NAME
dn_expand - Expands a compressed domain name
LIBRARY
Standard C Library (libc.a, libc.so)
SYNOPSIS
#include <sys/types.h> #include <netinet/in.h> #include <arpa/nameser.h> #include <resolv.h>
int dn_expand (
const u_char *message_ptr,
const u_char *end_of_message,
const u_char *compressed_name,
char *expanded_name,
int length );
PARAMETERS
Specifies a pointer to the beginning of a message. Points to the end of the original message that contains the compressed domain name.
Specifies a pointer to a compressed domain name. Specifies a pointer to a buffer that holds the resulting expanded domain name. Specifies
the size of the buffer pointed to by the expanded_name parameter.
DESCRIPTION
The dn_expand() function expands a compressed domain name to a full domain name, converting the expanded names to uppercase.
The dn_expand() function is one of a set of subroutines that form the resolver, a set of functions that resolves domain names. Global
information that is used by the resolver functions is kept in the _res data structure. The /include/resolv.h file contains the _res
structure definition.
RETURN VALUES
Upon successful completion, the dn_expand() function returns the size of the compressed domain name. Otherwise, a value of -1 is returned.
ERRORS
If an error occurs during a resolver operation, the h_errno external variable is set. Error code values and reasons are defined in
<netdb.h>.
FILES
Defines name server and domain name constants, structures, and values.
RELATED INFORMATION
Functions: dn_comp(3), dn_find(3), dn_skipname(3), putshort(3), putlong(3), res_init(3), res_mkquery(3), res_query(3), res_search(3),
res_send(3), _getshort(3), _getlong(3). delim off
dn_expand(3)
