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81 lines
2.7 KiB
81 lines
2.7 KiB
.\" |
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.\" Copyright 1998 by the Massachusetts Institute of Technology. |
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.\" |
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.\" Permission to use, copy, modify, and distribute this |
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.\" software and its documentation for any purpose and without |
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.\" fee is hereby granted, provided that the above copyright |
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.\" notice appear in all copies and that both that copyright |
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.\" notice and this permission notice appear in supporting |
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.\" documentation, and that the name of M.I.T. not be used in |
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.\" advertising or publicity pertaining to distribution of the |
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.\" software without specific, written prior permission. |
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.\" M.I.T. makes no representations about the suitability of |
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.\" this software for any purpose. It is provided "as is" |
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.\" without express or implied warranty. |
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.\" |
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.TH ARES_CREATE_QUERY 3 "17 Aug 2012" |
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.SH NAME |
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ares_create_query \- Compose a single-question DNS query buffer |
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.SH SYNOPSIS |
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.nf |
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.B #include <ares.h> |
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.PP |
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.B int ares_create_query(const char *\fIname\fP, int \fIdnsclass\fP,\ |
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int \fItype\fP, |
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.B unsigned short \fIid\fP, int \fIrd\fP,\ |
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unsigned char **\fIbuf\fP, |
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.B int *\fIbuflen\fP, int \fImax_udp_size\fP) |
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.fi |
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.SH DESCRIPTION |
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The |
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.B ares_create_query |
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function composes a DNS query with a single question. |
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The parameter |
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.I name |
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gives the query name as a NUL-terminated C string of period-separated |
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labels optionally ending with a period; periods and backslashes within |
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a label must be escaped with a backlash. The parameters |
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.I dnsclass |
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and |
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.I type |
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give the class and type of the query using the values defined in |
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.BR <arpa/nameser.h> . |
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The parameter |
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.I id |
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gives a 16-bit identifier for the query. The parameter |
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.I rd |
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should be nonzero if recursion is desired, zero if not. The query |
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will be placed in an allocated buffer, a pointer to which will be |
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stored in the variable pointed to by |
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.IR buf , |
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and the length of which will be stored in the variable pointed to by |
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.IR buflen . |
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It is the caller's responsibility to free this buffer using |
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\fIares_free_string(3)\fP when it is no longer needed. |
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The parameter |
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.I max_udp_size |
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should be nonzero to activate EDNS. Usage of \fIares_create_query(3)\fP\ with |
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.I max_udp_size |
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set to zero is equivalent to \fIares_mkquery(3)\fP. |
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.SH RETURN VALUES |
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.B ares_create_query |
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can return any of the following values: |
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.TP 15 |
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.B ARES_SUCCESS |
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Construction of the DNS query succeeded. |
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.TP 15 |
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.B ARES_EBADNAME |
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The query name |
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.I name |
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could not be encoded as a domain name, either because it contained a |
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zero-length label or because it contained a label of more than 63 |
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characters. |
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.TP 15 |
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.B ARES_ENOMEM |
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Memory was exhausted. |
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.SH AVAILABILITY |
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Added in c-ares 1.10.0 |
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.SH SEE ALSO |
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.BR ares_expand_name (3), |
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.BR ares_free_string (3) |
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.SH AUTHOR
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