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-rw-r--r-- | src/c-ares/ares_search.3 | 151 |
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diff --git a/src/c-ares/ares_search.3 b/src/c-ares/ares_search.3 new file mode 100644 index 000000000..2c85d20f6 --- /dev/null +++ b/src/c-ares/ares_search.3 @@ -0,0 +1,151 @@ +.\" +.\" Copyright 1998 by the Massachusetts Institute of Technology. +.\" +.\" Permission to use, copy, modify, and distribute this +.\" software and its documentation for any purpose and without +.\" fee is hereby granted, provided that the above copyright +.\" notice appear in all copies and that both that copyright +.\" notice and this permission notice appear in supporting +.\" documentation, and that the name of M.I.T. not be used in +.\" advertising or publicity pertaining to distribution of the +.\" software without specific, written prior permission. +.\" M.I.T. makes no representations about the suitability of +.\" this software for any purpose. It is provided "as is" +.\" without express or implied warranty. +.\" +.TH ARES_SEARCH 3 "24 July 1998" +.SH NAME +ares_search \- Initiate a DNS query with domain search +.SH SYNOPSIS +.nf +.B #include <ares.h> +.PP +.B typedef void (*ares_callback)(void *\fIarg\fP, int \fIstatus\fP, +.B int \fItimeouts\fP, unsigned char *\fIabuf\fP, int \fIalen\fP) +.PP +.B void ares_search(ares_channel \fIchannel\fP, const char *\fIname\fP, +.B int \fIdnsclass\fP, int \fItype\fP, ares_callback \fIcallback\fP, +.B void *\fIarg\fP) +.fi +.SH DESCRIPTION +The +.B ares_search +function initiates a series of single-question DNS queries on the name +service channel identified by +.IR channel , +using the channel's search domains as well as a host alias file given +by the HOSTALIAS environment variable. The parameter +.I name +gives the alias name or the base of the query name as a NUL-terminated +C string of period-separated labels; if it ends with a period, the +channel's search domains will not be used. Periods and backslashes +within a label must be escaped with a backslash. The parameters +.I dnsclass +and +.I type +give the class and type of the query using the values defined in +.BR <arpa/nameser.h> . +When the query sequence is complete or has failed, the ares library +will invoke +.IR callback . +Completion or failure of the query sequence may happen immediately, or +may happen during a later call to +.BR ares_process (3) +or +.BR ares_destroy (3). +.PP +The callback argument +.I arg +is copied from the +.B ares_search +argument +.IR arg . +The callback argument +.I status +indicates whether the query sequence ended with a successful query +and, if not, how the query sequence failed. It may have any of the +following values: +.TP 19 +.B ARES_SUCCESS +A query completed successfully. +.TP 19 +.B ARES_ENODATA +No query completed successfully; when the query was tried without a +search domain appended, a response was returned with no answers. +.TP 19 +.B ARES_EFORMERR +A query completed but the server claimed that the query was +malformatted. +.TP 19 +.B ARES_ESERVFAIL +No query completed successfully; when the query was tried without a +search domain appended, the server claimed to have experienced a +failure. (This code can only occur if the +.B ARES_FLAG_NOCHECKRESP +flag was specified at channel initialization time; otherwise, such +responses are ignored at the +.BR ares_send (3) +level.) +.TP 19 +.B ARES_ENOTFOUND +No query completed successfully; when the query was tried without a +search domain appended, the server reported that the queried-for +domain name was not found. +.TP 19 +.B ARES_ENOTIMP +A query completed but the server does not implement the operation +requested by the query. (This code can only occur if the +.B ARES_FLAG_NOCHECKRESP +flag was specified at channel initialization time; otherwise, such +responses are ignored at the +.BR ares_send (3) +level.) +.TP 19 +.B ARES_EREFUSED +A query completed but the server refused the query. (This code can +only occur returned if the +.B ARES_FLAG_NOCHECKRESP +flag was specified at channel initialization time; otherwise, such +responses are ignored at the +.BR ares_send (3) +level.) +.TP 19 +.B ARES_TIMEOUT +No name servers responded to a query within the timeout period. +.TP 19 +.B ARES_ECONNREFUSED +No name servers could be contacted. +.TP 19 +.B ARES_ENOMEM +Memory was exhausted. +.TP 19 +.B ARES_ECANCELLED +The query was cancelled. +.TP 19 +.B ARES_EDESTRUCTION +The name service channel +.I channel +is being destroyed; the query will not be completed. +.PP +The callback argument +.I timeouts +reports how many times a query timed out during the execution of the +given request. +.PP +If a query completed successfully, the callback argument +.I abuf +points to a result buffer of length +.IR alen . +If the query did not complete successfully, +.I abuf +will usually be NULL and +.I alen +will usually be 0, but in some cases an unsuccessful query result may +be placed in +.IR abuf . +.SH SEE ALSO +.BR ares_process (3) +.SH AUTHOR +Greg Hudson, MIT Information Systems +.br +Copyright 1998 by the Massachusetts Institute of Technology. |