77 строки
2.4 KiB
Groff
77 строки
2.4 KiB
Groff
.\" $Id$
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.\"
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.\" Copyright 1998, 2000 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_MKQUERY 3 "4 January 2000"
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.SH NAME
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ares_mkquery \- 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_mkquery(const char *\fIname\fP, int \fIdnsclass\fP, int \fItype\fP,
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.B unsigned short \fIid\fP, int \fIrd\fP, char **\fIbuf\fP,
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.B int *\fIbuflen\fP)
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.fi
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.SH DESCRIPTION
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The
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.B ares_mkquery
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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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.SH RETURN VALUES
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.B ares_mkquery
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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 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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Greg Hudson, MIT Information Systems
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.br
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Copyright 1998, 2000 by the Massachusetts Institute of Technology.
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