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16 .TH ARES_CREATE_QUERY 3 "17 Aug 2012"
18 ares_create_query \- Compose a single-question DNS query buffer
23 int ares_create_query(const char *\fIname\fP,
26 unsigned short \fIid\fP,
28 unsigned char **\fIbuf\fP,
30 int \fImax_udp_size\fP)
33 The \fIares_create_query(3)\fP function composes a DNS query with a single
34 question. The parameter \fIname\fP gives the query name as a NUL-terminated C
35 string of period-separated labels optionally ending with a period; periods and
36 backslashes within a label must be escaped with a backlash.
38 The parameters \fIdnsclass\fP and \fItype\fP give the class and type of the
39 query using the values defined in \fB<arpa/nameser.h>\fP.
41 The parameter \fIid\fP gives a 16-bit identifier for the query.
43 The parameter \fIrd\fP should be nonzero if recursion is desired, zero if not.
45 The query will be placed in an allocated buffer, a pointer to which will be
46 stored in the variable pointed to by \fIbuf\fP, and the length of which will
47 be stored in the variable pointed to by \fIbuflen\fP.
49 It is the caller's responsibility to free this buffer using
50 \fIares_free_string(3)\fP when it is no longer needed. The parameter
51 \fImax_udp_size\fP should be nonzero to activate EDNS. Usage of
52 \fIares_create_query(3)\fP\ with \fImax_udp_size\fP set to zero is equivalent
53 to using \fIares_mkquery(3)\fP.
56 can return any of the following values:
59 Construction of the DNS query succeeded.
64 could not be encoded as a domain name, either because it contained a
65 zero-length label or because it contained a label of more than 63
71 Added in c-ares 1.10.0
73 .BR ares_expand_name (3),
74 .BR ares_free_string (3),