sys::syslog.3

视频监控网络部分的协议ddns,的模块的实现代码,请大家大胆指正.

.\" Automatically generated by Pod::Man 2.16 (Pod::Simple 3.05)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sh \" Subsection heading
.br
.if t .Sp
.ne 5
.PP
\fB\\$1\fR
.PP
..
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" Set up some character translations and predefined strings.  \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote.  \*(C+ will
.\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    ds -- \(*W-
.    ds PI pi
.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
.    ds L" ""
.    ds R" ""
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds -- \|\(em\|
.    ds PI \(*p
.    ds L" ``
.    ds R" ''
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is turned on, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.ie \nF \{\
.    de IX
.    tm Index:\\$1\t\\n%\t"\\$2"
..
.    nr % 0
.    rr F
.\}
.el \{\
.    de IX
..
.\}
.\"
.\" Accent mark definitions (@(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2).
.\" Fear.  Run.  Save yourself.  No user-serviceable parts.
.    \" fudge factors for nroff and troff
.if n \{\
.    ds #H 0
.    ds #V .8m
.    ds #F .3m
.    ds #[ \f1
.    ds #] \fP
.\}
.if t \{\
.    ds #H ((1u-(\\\\n(.fu%2u))*.13m)
.    ds #V .6m
.    ds #F 0
.    ds #[ \&
.    ds #] \&
.\}
.    \" simple accents for nroff and troff
.if n \{\
.    ds ' \&
.    ds ` \&
.    ds ^ \&
.    ds , \&
.    ds ~ ~
.    ds /
.\}
.if t \{\
.    ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u"
.    ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u'
.    ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u'
.    ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u'
.    ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u'
.    ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u'
.\}
.    \" troff and (daisy-wheel) nroff accents
.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V'
.ds 8 \h'\*(#H'\(*b\h'-\*(#H'
.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#]
.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H'
.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u'
.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#]
.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#]
.ds ae a\h'-(\w'a'u*4/10)'e
.ds Ae A\h'-(\w'A'u*4/10)'E
.    \" corrections for vroff
.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u'
.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u'
.    \" for low resolution devices (crt and lpr)
.if \n(.H>23 .if \n(.V>19 \
\{\
.    ds : e
.    ds 8 ss
.    ds o a
.    ds d- d\h'-1'\(ga
.    ds D- D\h'-1'\(hy
.    ds th \o'bp'
.    ds Th \o'LP'
.    ds ae ae
.    ds Ae AE
.\}
.rm #[ #] #H #V #F C
.\" ========================================================================
.\"
.IX Title "Sys::Syslog 3"
.TH Sys::Syslog 3 "2007-12-18" "perl v5.10.0" "Perl Programmers Reference Guide"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
Sys::Syslog \- Perl interface to the UNIX syslog(3) calls
.SH "VERSION"
.IX Header "VERSION"
Version 0.22
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
.Vb 3
\&    use Sys::Syslog;                          # all except setlogsock(), or:
\&    use Sys::Syslog qw(:DEFAULT setlogsock);  # default set, plus setlogsock()
\&    use Sys::Syslog qw(:standard :macros);    # standard functions, plus macros
\&
\&    openlog $ident, $logopt, $facility;       # don\*(Aqt forget this
\&    syslog $priority, $format, @args;
\&    $oldmask = setlogmask $mask_priority;
\&    closelog;
.Ve
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
\&\f(CW\*(C`Sys::Syslog\*(C'\fR is an interface to the \s-1UNIX\s0 \f(CWsyslog(3)\fR program.
Call \f(CW\*(C`syslog()\*(C'\fR with a string priority and a list of \f(CW\*(C`printf()\*(C'\fR args
just like \f(CWsyslog(3)\fR.
.PP
You can find a kind of \s-1FAQ\s0 in \*(L"\s-1THE\s0 \s-1RULES\s0 \s-1OF\s0 \s-1SYS::SYSLOG\s0\*(R".  Please read 
it before coding, and again before asking questions.
.SH "EXPORTS"
.IX Header "EXPORTS"
\&\f(CW\*(C`Sys::Syslog\*(C'\fR exports the following \f(CW\*(C`Exporter\*(C'\fR tags:
.IP "\(bu" 4
\&\f(CW\*(C`:standard\*(C'\fR exports the standard \f(CWsyslog(3)\fR functions:
.Sp
.Vb 1
\&    openlog closelog setlogmask syslog
.Ve
.IP "\(bu" 4
\&\f(CW\*(C`:extended\*(C'\fR exports the Perl specific functions for \f(CWsyslog(3)\fR:
.Sp
.Vb 1
\&    setlogsock
.Ve
.IP "\(bu" 4
\&\f(CW\*(C`:macros\*(C'\fR exports the symbols corresponding to most of your \f(CWsyslog(3)\fR 
macros and the \f(CW\*(C`LOG_UPTO()\*(C'\fR and \f(CW\*(C`LOG_MASK()\*(C'\fR functions. 
See \*(L"\s-1CONSTANTS\s0\*(R" for the supported constants and their meaning.
.PP
By default, \f(CW\*(C`Sys::Syslog\*(C'\fR exports the symbols from the \f(CW\*(C`:standard\*(C'\fR tag.
.SH "FUNCTIONS"
.IX Header "FUNCTIONS"
.ie n .IP "\fBopenlog($ident, \fB$logopt\fB, \f(BI$facility\fB)\fR" 4
.el .IP "\fBopenlog($ident, \f(CB$logopt\fB, \f(CB$facility\fB)\fR" 4
.IX Item "openlog($ident, $logopt, $facility)"
Opens the syslog.
\&\f(CW$ident\fR is prepended to every message.  \f(CW$logopt\fR contains zero or
more of the options detailed below.  \f(CW$facility\fR specifies the part 
of the system to report about, for example \f(CW\*(C`LOG_USER\*(C'\fR or \f(CW\*(C`LOG_LOCAL0\*(C'\fR:
see \*(L"Facilities\*(R" for a list of well-known facilities, and your 
\&\f(CWsyslog(3)\fR documentation for the facilities available in your system. 
Check \*(L"\s-1SEE\s0 \s-1ALSO\s0\*(R" for useful links. Facility can be given as a string 
or a numeric macro.
.Sp
This function will croak if it can't connect to the syslog daemon.
.Sp
Note that \f(CW\*(C`openlog()\*(C'\fR now takes three arguments, just like \f(CWopenlog(3)\fR.
.Sp
\&\fBYou should use \f(CB\*(C`openlog()\*(C'\fB before calling \f(CB\*(C`syslog()\*(C'\fB.\fR
.Sp
\&\fBOptions\fR
.RS 4
.IP "\(bu" 4
\&\f(CW\*(C`cons\*(C'\fR \- This option is ignored, since the failover mechanism will drop 
down to the console automatically if all other media fail.
.IP "\(bu" 4
\&\f(CW\*(C`ndelay\*(C'\fR \- Open the connection immediately (normally, the connection is
opened when the first message is logged).
.IP "\(bu" 4
\&\f(CW\*(C`nofatal\*(C'\fR \- When set to true, \f(CW\*(C`openlog()\*(C'\fR and \f(CW\*(C`syslog()\*(C'\fR will only 
emit warnings instead of dying if the connection to the syslog can't 
be established.
.IP "\(bu" 4
\&\f(CW\*(C`nowait\*(C'\fR \- Don't wait for child processes that may have been created 
while logging the message.  (The \s-1GNU\s0 C library does not create a child
process, so this option has no effect on Linux.)
.IP "\(bu" 4
\&\f(CW\*(C`perror\*(C'\fR \- Write the message to standard error output as well to the
system log.
.IP "\(bu" 4
\&\f(CW\*(C`pid\*(C'\fR \- Include \s-1PID\s0 with each message.
.RE
.RS 4
.Sp
\&\fBExamples\fR
.Sp
Open the syslog with options \f(CW\*(C`ndelay\*(C'\fR and \f(CW\*(C`pid\*(C'\fR, and with facility \f(CW\*(C`LOCAL0\*(C'\fR:
.Sp
.Vb 1
\&    openlog($name, "ndelay,pid", "local0");
.Ve
.Sp
Same thing, but this time using the macro corresponding to \f(CW\*(C`LOCAL0\*(C'\fR:
.Sp
.Vb 1
\&    openlog($name, "ndelay,pid", LOG_LOCAL0);
.Ve
.RE
.ie n .IP "\fBsyslog($priority, \fB$message\fB)\fR" 4
.el .IP "\fBsyslog($priority, \f(CB$message\fB)\fR" 4
.IX Item "syslog($priority, $message)"
.PD 0
.ie n .IP "\fBsyslog($priority, \fB$format\fB, \f(BI@args\fB)\fR" 4
.el .IP "\fBsyslog($priority, \f(CB$format\fB, \f(CB@args\fB)\fR" 4
.IX Item "syslog($priority, $format, @args)"
.PD
If \f(CW$priority\fR permits, logs \f(CW$message\fR or \f(CW\*(C`sprintf($format, @args)\*(C'\fR
with the addition that \f(CW%m\fR in \f(CW$message\fR or \f(CW$format\fR is replaced with
\&\f(CW"$!"\fR (the latest error message).
.Sp
\&\f(CW$priority\fR can specify a level, or a level and a facility.  Levels and 
facilities can be given as strings or as macros.  When using the \f(CW\*(C`eventlog\*(C'\fR
mechanism, priorities \f(CW\*(C`DEBUG\*(C'\fR and \f(CW\*(C`INFO\*(C'\fR are mapped to event type 
\&\f(CW\*(C`informational\*(C'\fR, \f(CW\*(C`NOTICE\*(C'\fR and \f(CW\*(C`WARNIN\*(C'\fR to \f(CW\*(C`warning\*(C'\fR and \f(CW\*(C`ERR\*(C'\fR to 
\&\f(CW\*(C`EMERG\*(C'\fR to \f(CW\*(C`error\*(C'\fR.
.Sp
If you didn't use \f(CW\*(C`openlog()\*(C'\fR before using \f(CW\*(C`syslog()\*(C'\fR, \f(CW\*(C`syslog()\*(C'\fR will 
try to guess the \f(CW$ident\fR by extracting the shortest prefix of 
\&\f(CW$format\fR that ends in a \f(CW":"\fR.
.Sp
\&\fBExamples\fR
.Sp
.Vb 2
\&    syslog("info", $message);           # informational level
\&    syslog(LOG_INFO, $message);         # informational level
\&
\&    syslog("info|local0", $message);        # information level, Local0 facility
\&    syslog(LOG_INFO|LOG_LOCAL0, $message);  # information level, Local0 facility
.Ve
.RS 4
.IP "\fBNote\fR" 4
.IX Item "Note"
\&\f(CW\*(C`Sys::Syslog\*(C'\fR version v0.07 and older passed the \f(CW$message\fR as the 
formatting string to \f(CW\*(C`sprintf()\*(C'\fR even when no formatting arguments
were provided.  If the code calling \f(CW\*(C`syslog()\*(C'\fR might execute with 
older versions of this module, make sure to call the function as
\&\f(CW\*(C`syslog($priority, "%s", $message)\*(C'\fR instead of \f(CW\*(C`syslog($priority,
$message)\*(C'\fR.  This protects against hostile formatting sequences that
might show up if \f(CW$message\fR contains tainted data.
.RE
.RS 4
.RE
.IP "\fBsetlogmask($mask_priority)\fR" 4
.IX Item "setlogmask($mask_priority)"
Sets the log mask for the current process to \f(CW$mask_priority\fR and 
returns the old mask.  If the mask argument is 0, the current log mask 
is not modified.  See \*(L"Levels\*(R" for the list of available levels. 
You can use the \f(CW\*(C`LOG_UPTO()\*(C'\fR function to allow all levels up to a 
given priority (but it only accept the numeric macros as arguments).
.Sp
\&\fBExamples\fR
.Sp
Only log errors:
.Sp
.Vb 1
\&    setlogmask( LOG_MASK(LOG_ERR) );
.Ve
.Sp
Log everything except informational messages:
.Sp
.Vb 1
\&    setlogmask( ~(LOG_MASK(LOG_INFO)) );
.Ve
.Sp
Log critical messages, errors and warnings:
.Sp
.Vb 1
\&    setlogmask( LOG_MASK(LOG_CRIT) | LOG_MASK(LOG_ERR) | LOG_MASK(LOG_WARNING) );
.Ve
.Sp
Log all messages up to debug:
.Sp
.Vb 1
\&    setlogmask( LOG_UPTO(LOG_DEBUG) );
.Ve
.IP "\fBsetlogsock($sock_type)\fR" 4
.IX Item "setlogsock($sock_type)"
.PD 0
.ie n .IP "\fBsetlogsock($sock_type, \fB$stream_location\fB)\fR (added in Perl 5.004_02)" 4
.el .IP "\fBsetlogsock($sock_type, \f(CB$stream_location\fB)\fR (added in Perl 5.004_02)" 4
.IX Item "setlogsock($sock_type, $stream_location) (added in Perl 5.004_02)"
.PD
Sets the socket type to be used for the next call to
\&\f(CW\*(C`openlog()\*(C'\fR or \f(CW\*(C`syslog()\*(C'\fR and returns true on success,
\&\f(CW\*(C`undef\*(C'\fR on failure. The available mechanisms are:
.RS 4
.IP "\(bu" 4
\&\f(CW"native"\fR \- use the native C functions from your \f(CWsyslog(3)\fR library
(added in \f(CW\*(C`Sys::Syslog\*(C'\fR 0.15).
.IP "\(bu" 4
\&\f(CW"eventlog"\fR \- send messages to the Win32 events logger (Win32 only; 
added in \f(CW\*(C`Sys::Syslog\*(C'\fR 0.19).
.IP "\(bu" 4
\&\f(CW"tcp"\fR \- connect to a \s-1TCP\s0 socket, on the \f(CW\*(C`syslog/tcp\*(C'\fR or \f(CW\*(C`syslogng/tcp\*(C'\fR 
service.
.IP "\(bu" 4
\&\f(CW"udp"\fR \- connect to a \s-1UDP\s0 socket, on the \f(CW\*(C`syslog/udp\*(C'\fR service.
.IP "\(bu" 4
\&\f(CW"inet"\fR \- connect to an \s-1INET\s0 socket, either \s-1TCP\s0 or \s-1UDP\s0, tried in that order.
.IP "\(bu" 4
\&\f(CW"unix"\fR \- connect to a \s-1UNIX\s0 domain socket (in some systems a character 
special device).  The name of that socket is the second parameter or, if 
you omit the second parameter, the value returned by the \f(CW\*(C`_PATH_LOG\*(C'\fR macro 
(if your system defines it), or \fI/dev/log\fR or \fI/dev/conslog\fR, whatever is 
writable.
.IP "\(bu" 4
\&\f(CW"stream"\fR \- connect to the stream indicated by the pathname provided as 
the optional second parameter, or, if omitted, to \fI/dev/conslog\fR. 
For example Solaris and \s-1IRIX\s0 system may prefer \f(CW"stream"\fR instead of \f(CW"unix"\fR.
.IP "\(bu" 4
\&\f(CW"pipe"\fR \- connect to the named pipe indicated by the pathname provided as 
the optional second parameter, or, if omitted, to the value returned by 
the \f(CW\*(C`_PATH_LOG\*(C'\fR macro (if your system defines it), or \fI/dev/log\fR