re.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.

.IX Subsection "'Debug' mode"
Similarly \f(CW\*(C`use re \*(AqDebug\*(Aq\*(C'\fR produces debugging output, the difference
being that it allows the fine tuning of what debugging output will be
emitted. Options are divided into three groups, those related to
compilation, those related to execution and those related to special
purposes. The options are as follows:
.IP "Compile related options" 4
.IX Item "Compile related options"
.RS 4
.PD 0
.IP "\s-1COMPILE\s0" 4
.IX Item "COMPILE"
.PD
Turns on all compile related debug options.
.IP "\s-1PARSE\s0" 4
.IX Item "PARSE"
Turns on debug output related to the process of parsing the pattern.
.IP "\s-1OPTIMISE\s0" 4
.IX Item "OPTIMISE"
Enables output related to the optimisation phase of compilation.
.IP "\s-1TRIEC\s0" 4
.IX Item "TRIEC"
Detailed info about trie compilation.
.IP "\s-1DUMP\s0" 4
.IX Item "DUMP"
Dump the final program out after it is compiled and optimised.
.RE
.RS 4
.RE
.IP "Execute related options" 4
.IX Item "Execute related options"
.RS 4
.PD 0
.IP "\s-1EXECUTE\s0" 4
.IX Item "EXECUTE"
.PD
Turns on all execute related debug options.
.IP "\s-1MATCH\s0" 4
.IX Item "MATCH"
Turns on debugging of the main matching loop.
.IP "\s-1TRIEE\s0" 4
.IX Item "TRIEE"
Extra debugging of how tries execute.
.IP "\s-1INTUIT\s0" 4
.IX Item "INTUIT"
Enable debugging of start point optimisations.
.RE
.RS 4
.RE
.IP "Extra debugging options" 4
.IX Item "Extra debugging options"
.RS 4
.PD 0
.IP "\s-1EXTRA\s0" 4
.IX Item "EXTRA"
.PD
Turns on all \*(L"extra\*(R" debugging options.
.IP "\s-1BUFFERS\s0" 4
.IX Item "BUFFERS"
Enable debugging the capture buffer storage during match. Warning,
this can potentially produce extremely large output.
.IP "\s-1TRIEM\s0" 4
.IX Item "TRIEM"
Enable enhanced \s-1TRIE\s0 debugging. Enhances both \s-1TRIEE\s0
and \s-1TRIEC\s0.
.IP "\s-1STATE\s0" 4
.IX Item "STATE"
Enable debugging of states in the engine.
.IP "\s-1STACK\s0" 4
.IX Item "STACK"
Enable debugging of the recursion stack in the engine. Enabling
or disabling this option automatically does the same for debugging
states as well. This output from this can be quite large.
.IP "\s-1OPTIMISEM\s0" 4
.IX Item "OPTIMISEM"
Enable enhanced optimisation debugging and start point optimisations.
Probably not useful except when debugging the regex engine itself.
.IP "\s-1OFFSETS\s0" 4
.IX Item "OFFSETS"
Dump offset information. This can be used to see how regops correlate
to the pattern. Output format is
.Sp
.Vb 1
\&   NODENUM:POSITION[LENGTH]
.Ve
.Sp
Where 1 is the position of the first char in the string. Note that position
can be 0, or larger than the actual length of the pattern, likewise length
can be zero.
.IP "\s-1OFFSETSDBG\s0" 4
.IX Item "OFFSETSDBG"
Enable debugging of offsets information. This emits copious
amounts of trace information and doesn't mesh well with other
debug options.
.Sp
Almost definitely only useful to people hacking
on the offsets part of the debug engine.
.RE
.RS 4
.RE
.IP "Other useful flags" 4
.IX Item "Other useful flags"
These are useful shortcuts to save on the typing.
.RS 4
.IP "\s-1ALL\s0" 4
.IX Item "ALL"
Enable all options at once except \s-1OFFSETS\s0, \s-1OFFSETSDBG\s0 and \s-1BUFFERS\s0
.IP "All" 4
.IX Item "All"
Enable \s-1DUMP\s0 and all execute options. Equivalent to:
.Sp
.Vb 1
\&  use re \*(Aqdebug\*(Aq;
.Ve
.IP "\s-1MORE\s0" 4
.IX Item "MORE"
.PD 0
.IP "More" 4
.IX Item "More"
.PD
Enable \s-1TRIEM\s0 and all execute compile and execute options.
.RE
.RS 4
.RE
.PP
As of 5.9.5 the directive \f(CW\*(C`use re \*(Aqdebug\*(Aq\*(C'\fR and its equivalents are
lexically scoped, as the other directives are.  However they have both
compile-time and run-time effects.
.Sh "Exportable Functions"
.IX Subsection "Exportable Functions"
As of perl 5.9.5 're' debug contains a number of utility functions that
may be optionally exported into the caller's namespace. They are listed
below.
.IP "is_regexp($ref)" 4
.IX Item "is_regexp($ref)"
Returns true if the argument is a compiled regular expression as returned
by \f(CW\*(C`qr//\*(C'\fR, false if it is not.
.Sp
This function will not be confused by overloading or blessing. In
internals terms, this extracts the regexp pointer out of the
PERL_MAGIC_qr structure so it it cannot be fooled.
.IP "regexp_pattern($ref)" 4
.IX Item "regexp_pattern($ref)"
If the argument is a compiled regular expression as returned by \f(CW\*(C`qr//\*(C'\fR,
then this function returns the pattern.
.Sp
In list context it returns a two element list, the first element
containing the pattern and the second containing the modifiers used when
the pattern was compiled.
.Sp
.Vb 1
\&  my ($pat, $mods) = regexp_pattern($ref);
.Ve
.Sp
In scalar context it returns the same as perl would when strigifying a raw
\&\f(CW\*(C`qr//\*(C'\fR with the same pattern inside.  If the argument is not a compiled
reference then this routine returns false but defined in scalar context,
and the empty list in list context. Thus the following
.Sp
.Vb 1
\&    if (regexp_pattern($ref) eq \*(Aq(?i\-xsm:foo)\*(Aq)
.Ve
.Sp
will be warning free regardless of what \f(CW$ref\fR actually is.
.Sp
Like \f(CW\*(C`is_regexp\*(C'\fR this function will not be confused by overloading
or blessing of the object.
.IP "regmust($ref)" 4
.IX Item "regmust($ref)"
If the argument is a compiled regular expression as returned by \f(CW\*(C`qr//\*(C'\fR,
then this function returns what the optimiser consiers to be the longest
anchored fixed string and longest floating fixed string in the pattern.
.Sp
A \fIfixed string\fR is defined as being a substring that must appear for the
pattern to match. An \fIanchored fixed string\fR is a fixed string that must
appear at a particular offset from the beginning of the match. A \fIfloating
fixed string\fR is defined as a fixed string that can appear at any point in
a range of positions relative to the start of the match. For example,
.Sp
.Vb 3
\&    my $qr = qr/here .* there/x;
\&    my ($anchored, $floating) = regmust($qr);
\&    print "anchored:\*(Aq$anchored\*(Aq\enfloating:\*(Aq$floating\*(Aq\en";
.Ve
.Sp
results in
.Sp
.Vb 2
\&    anchored:\*(Aqhere\*(Aq
\&    floating:\*(Aqthere\*(Aq
.Ve
.Sp
Because the \f(CW\*(C`here\*(C'\fR is before the \f(CW\*(C`.*\*(C'\fR in the pattern, its position
can be determined exactly. That's not true, however, for the \f(CW\*(C`there\*(C'\fR;
it could appear at any point after where the anchored string appeared.
Perl uses both for its optimisations, prefering the longer, or, if they are
equal, the floating.
.Sp
\&\fB\s-1NOTE:\s0\fR This may not necessarily be the definitive longest anchored and
floating string. This will be what the optimiser of the Perl that you
are using thinks is the longest. If you believe that the result is wrong
please report it via the perlbug utility.
.IP "regname($name,$all)" 4
.IX Item "regname($name,$all)"
Returns the contents of a named buffer of the last successful match. If
\&\f(CW$all\fR is true, then returns an array ref containing one entry per buffer,
otherwise returns the first defined buffer.
.IP "regnames($all)" 4
.IX Item "regnames($all)"
Returns a list of all of the named buffers defined in the last successful
match. If \f(CW$all\fR is true, then it returns all names defined, if not it returns
only names which were involved in the match.
.IP "\fIregnames_count()\fR" 4
.IX Item "regnames_count()"
Returns the number of distinct names defined in the pattern used
for the last successful match.
.Sp
\&\fBNote:\fR this result is always the actual number of distinct
named buffers defined, it may not actually match that which is
returned by \f(CW\*(C`regnames()\*(C'\fR and related routines when those routines
have not been called with the \f(CW$all\fR parameter set.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
\&\*(L"Pragmatic Modules\*(R" in perlmodlib.