package re;
-our $VERSION = 0.06_01;
+# pragma for controlling the regexp engine
+use strict;
+use warnings;
+
+our $VERSION = "0.11";
+our @ISA = qw(Exporter);
+our @EXPORT_OK = ('regmust',
+ qw(is_regexp regexp_pattern
+ regname regnames regnames_count));
+our %EXPORT_OK = map { $_ => 1 } @EXPORT_OK;
+
+my %bitmask = (
+ taint => 0x00100000, # HINT_RE_TAINT
+ eval => 0x00200000, # HINT_RE_EVAL
+);
+
+sub setcolor {
+ eval { # Ignore errors
+ require Term::Cap;
+
+ my $terminal = Tgetent Term::Cap ({OSPEED => 9600}); # Avoid warning.
+ my $props = $ENV{PERL_RE_TC} || 'md,me,so,se,us,ue';
+ my @props = split /,/, $props;
+ my $colors = join "\t", map {$terminal->Tputs($_,1)} @props;
+
+ $colors =~ s/\0//g;
+ $ENV{PERL_RE_COLORS} = $colors;
+ };
+ if ($@) {
+ $ENV{PERL_RE_COLORS} ||= qq'\t\t> <\t> <\t\t';
+ }
+
+}
+
+my %flags = (
+ COMPILE => 0x0000FF,
+ PARSE => 0x000001,
+ OPTIMISE => 0x000002,
+ TRIEC => 0x000004,
+ DUMP => 0x000008,
+ FLAGS => 0x000010,
+
+ EXECUTE => 0x00FF00,
+ INTUIT => 0x000100,
+ MATCH => 0x000200,
+ TRIEE => 0x000400,
+
+ EXTRA => 0xFF0000,
+ TRIEM => 0x010000,
+ OFFSETS => 0x020000,
+ OFFSETSDBG => 0x040000,
+ STATE => 0x080000,
+ OPTIMISEM => 0x100000,
+ STACK => 0x280000,
+ BUFFERS => 0x400000,
+ GPOS => 0x800000,
+);
+$flags{ALL} = -1 & ~($flags{OFFSETS}|$flags{OFFSETSDBG}|$flags{BUFFERS});
+$flags{All} = $flags{all} = $flags{DUMP} | $flags{EXECUTE};
+$flags{Extra} = $flags{EXECUTE} | $flags{COMPILE} | $flags{GPOS};
+$flags{More} = $flags{MORE} = $flags{All} | $flags{TRIEC} | $flags{TRIEM} | $flags{STATE};
+$flags{State} = $flags{DUMP} | $flags{EXECUTE} | $flags{STATE};
+$flags{TRIE} = $flags{DUMP} | $flags{EXECUTE} | $flags{TRIEC};
+
+if (defined &DynaLoader::boot_DynaLoader) {
+ require XSLoader;
+ XSLoader::load( __PACKAGE__, $VERSION);
+}
+# else we're miniperl
+# We need to work for miniperl, because the XS toolchain uses Text::Wrap, which
+# uses re 'taint'.
+
+sub _load_unload {
+ my ($on)= @_;
+ if ($on) {
+ # We call install() every time, as if we didn't, we wouldn't
+ # "see" any changes to the color environment var since
+ # the last time it was called.
+
+ # install() returns an integer, which if casted properly
+ # in C resolves to a structure containing the regexp
+ # hooks. Setting it to a random integer will guarantee
+ # segfaults.
+ $^H{regcomp} = install();
+ } else {
+ delete $^H{regcomp};
+ }
+}
+
+sub bits {
+ my $on = shift;
+ my $bits = 0;
+ unless (@_) {
+ require Carp;
+ Carp::carp("Useless use of \"re\" pragma");
+ }
+ foreach my $idx (0..$#_){
+ my $s=$_[$idx];
+ if ($s eq 'Debug' or $s eq 'Debugcolor') {
+ setcolor() if $s =~/color/i;
+ ${^RE_DEBUG_FLAGS} = 0 unless defined ${^RE_DEBUG_FLAGS};
+ for my $idx ($idx+1..$#_) {
+ if ($flags{$_[$idx]}) {
+ if ($on) {
+ ${^RE_DEBUG_FLAGS} |= $flags{$_[$idx]};
+ } else {
+ ${^RE_DEBUG_FLAGS} &= ~ $flags{$_[$idx]};
+ }
+ } else {
+ require Carp;
+ Carp::carp("Unknown \"re\" Debug flag '$_[$idx]', possible flags: ",
+ join(", ",sort keys %flags ) );
+ }
+ }
+ _load_unload($on ? 1 : ${^RE_DEBUG_FLAGS});
+ last;
+ } elsif ($s eq 'debug' or $s eq 'debugcolor') {
+ setcolor() if $s =~/color/i;
+ _load_unload($on);
+ last;
+ } elsif (exists $bitmask{$s}) {
+ $bits |= $bitmask{$s};
+ } elsif ($EXPORT_OK{$s}) {
+ require Exporter;
+ re->export_to_level(2, 're', $s);
+ } else {
+ require Carp;
+ Carp::carp("Unknown \"re\" subpragma '$s' (known ones are: ",
+ join(', ', map {qq('$_')} 'debug', 'debugcolor', sort keys %bitmask),
+ ")");
+ }
+ }
+ $bits;
+}
+
+sub import {
+ shift;
+ $^H |= bits(1, @_);
+}
+
+sub unimport {
+ shift;
+ $^H &= ~ bits(0, @_);
+}
+
+1;
+
+__END__
=head1 NAME
/foo${pat}bar/; # disallowed (with or without -T switch)
}
- use re 'debug'; # NOT lexically scoped (as others are)
- /^(.*)$/s; # output debugging info during
- # compile and run time
+ use re 'debug'; # output debugging info during
+ /^(.*)$/s; # compile and run time
+
use re 'debugcolor'; # same as 'debug', but with colored output
...
use re qw(Debug All); # Finer tuned debugging options.
- use re qw(Debug More); # Similarly not lexically scoped.
- no re qw(Debug ALL); # Turn of all re dugging and unload the module.
+ use re qw(Debug More);
+ no re qw(Debug ALL); # Turn of all re debugging in this scope
+
+ use re qw(is_regexp regexp_pattern); # import utility functions
+ my ($pat,$mods)=regexp_pattern(qr/foo/i);
+ if (is_regexp($obj)) {
+ print "Got regexp: ",
+ scalar regexp_pattern($obj); # just as perl would stringify it
+ } # but no hassle with blessed re's.
(We use $^X in these examples because it's tainted by default.)
=head1 DESCRIPTION
+=head2 'taint' mode
+
When C<use re 'taint'> is in effect, and a tainted string is the target
-of a regex, the regex memories (or values returned by the m// operator
-in list context) are tainted. This feature is useful when regex operations
+of a regexp, the regexp memories (or values returned by the m// operator
+in list context) are tainted. This feature is useful when regexp operations
on tainted data aren't meant to extract safe substrings, but to perform
other transformations.
-When C<use re 'eval'> is in effect, a regex is allowed to contain
-C<(?{ ... })> zero-width assertions even if regular expression contains
+=head2 'eval' mode
+
+When C<use re 'eval'> is in effect, a regexp is allowed to contain
+C<(?{ ... })> zero-width assertions and C<(??{ ... })> postponed
+subexpressions, even if the regular expression contains
variable interpolation. That is normally disallowed, since it is a
potential security risk. Note that this pragma is ignored when the regular
expression is obtained from tainted data, i.e. evaluation is always
-disallowed with tainted regular expressions. See L<perlre/(?{ code })>.
+disallowed with tainted regular expressions. See L<perlre/(?{ code })>
+and L<perlre/(??{ code })>.
For the purpose of this pragma, interpolation of precompiled regular
expressions (i.e., the result of C<qr//>) is I<not> considered variable
/foo${pat}bar/
I<is> allowed if $pat is a precompiled regular expression, even
-if $pat contains C<(?{ ... })> assertions.
+if $pat contains C<(?{ ... })> assertions or C<(??{ ... })> subexpressions.
+
+=head2 'debug' mode
When C<use re 'debug'> is in effect, perl emits debugging messages when
compiling and using regular expressions. The output is the same as that
strings on/off, pre-point part on/off.
See L<perldebug/"Debugging regular expressions"> for additional info.
+As of 5.9.5 the directive C<use re 'debug'> and its equivalents are
+lexically scoped, as the other directives are. However they have both
+compile-time and run-time effects.
+
+See L<perlmodlib/Pragmatic Modules>.
+
+=head2 'Debug' mode
+
Similarly C<use re 'Debug'> 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
Enables output related to the optimisation phase of compilation.
-=item TRIE_COMPILE
+=item TRIEC
Detailed info about trie compilation.
Dump the final program out after it is compiled and optimised.
-=item OFFSETS
-
-Dump offset information. This can be used to see how regops correlate
-to the pattern. Output format is
-
- NODENUM:POSITION[LENGTH]
-
-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.
-
=back
=item Execute related options
Turns on debugging of the main matching loop.
-=item TRIE_EXECUTE
+=item TRIEE
Extra debugging of how tries execute.
Turns on all "extra" debugging options.
-=item TRIE_MORE
+=item BUFFERS
+
+Enable debugging the capture buffer storage during match. Warning,
+this can potentially produce extremely large output.
+
+=item TRIEM
+
+Enable enhanced TRIE debugging. Enhances both TRIEE
+and TRIEC.
+
+=item STATE
-Enable enhanced TRIE debugging. Enhances both TRIE_EXECUTE
-and TRIE_COMPILE.
+Enable debugging of states in the engine.
-=item OFFSETS_DEBUG
+=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.
+
+=item OPTIMISEM
+
+Enable enhanced optimisation debugging and start point optimisations.
+Probably not useful except when debugging the regexp engine itself.
+
+=item OFFSETS
+
+Dump offset information. This can be used to see how regops correlate
+to the pattern. Output format is
+
+ NODENUM:POSITION[LENGTH]
+
+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.
+
+=item OFFSETSDBG
Enable debugging of offsets information. This emits copious
-amounts of trace information and doesnt mesh well with other
+amounts of trace information and doesn't mesh well with other
debug options.
-Almost definately only useful to people hacking
+Almost definitely only useful to people hacking
on the offsets part of the debug engine.
=back
=item ALL
-Enable all compile and execute options at once.
+Enable all options at once except OFFSETS, OFFSETSDBG and BUFFERS
=item All
-Enable DUMP and all execute options. Equivelent to:
+Enable DUMP and all execute options. Equivalent to:
use re 'debug';
=item More
-Enable TRIE_MORE and all execute compile and execute options.
+Enable TRIEM and all execute compile and execute options.
-=back 4
+=back
-=back 4
+=back
-The directive C<use re 'debug'> and its equivalents are I<not> lexically
-scoped, as the other directives are. They have both compile-time and run-time
-effects.
+As of 5.9.5 the directive C<use re 'debug'> and its equivalents are
+lexically scoped, as the other directives are. However they have both
+compile-time and run-time effects.
-See L<perlmodlib/Pragmatic Modules>.
+=head2 Exportable Functions
-=cut
+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.
-# N.B. File::Basename contains a literal for 'taint' as a fallback. If
-# taint is changed here, File::Basename must be updated as well.
-my %bitmask = (
-taint => 0x00100000, # HINT_RE_TAINT
-eval => 0x00200000, # HINT_RE_EVAL
-);
+=over 4
-sub setcolor {
- eval { # Ignore errors
- require Term::Cap;
+=item is_regexp($ref)
- my $terminal = Tgetent Term::Cap ({OSPEED => 9600}); # Avoid warning.
- my $props = $ENV{PERL_RE_TC} || 'md,me,so,se,us,ue';
- my @props = split /,/, $props;
- my $colors = join "\t", map {$terminal->Tputs($_,1)} @props;
+Returns true if the argument is a compiled regular expression as returned
+by C<qr//>, false if it is not.
- $colors =~ s/\0//g;
- $ENV{PERL_RE_COLORS} = $colors;
- };
-}
+This function will not be confused by overloading or blessing. In
+internals terms, this extracts the regexp pointer out of the
+PERL_MAGIC_qr structure so it it cannot be fooled.
-my %flags = (
- COMPILE => 0x0000FF,
- PARSE => 0x000001,
- OPTIMISE => 0x000002,
- TRIE_COMPILE => 0x000004,
- DUMP => 0x000008,
- OFFSETS => 0x000010,
+=item regexp_pattern($ref)
- EXECUTE => 0x00FF00,
- INTUIT => 0x000100,
- MATCH => 0x000200,
- TRIE_EXECUTE => 0x000400,
+If the argument is a compiled regular expression as returned by C<qr//>,
+then this function returns the pattern.
- EXTRA => 0xFF0000,
- TRIE_MORE => 0x010000,
- OFFSETS_DEBUG => 0x020000,
-);
-$flags{ALL} = $flags{COMPILE} | $flags{EXECUTE};
-$flags{All} = $flags{all} = $flags{DUMP} | $flags{EXECUTE};
-$flags{More} = $flags{MORE} = $flags{ALL} | $flags{TRIE_MORE};
+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.
-my $installed = 0;
+ my ($pat, $mods) = regexp_pattern($ref);
-sub _load_unload {
- my $on = shift;
- require XSLoader;
- XSLoader::load('re');
- install($on);
-}
+In scalar context it returns the same as perl would when stringifying a raw
+C<qr//> 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
-sub bits {
- my $on = shift;
- my $bits = 0;
- unless (@_) {
- require Carp;
- Carp::carp("Useless use of \"re\" pragma");
- }
- foreach my $idx (0..$#_){
- my $s=$_[$idx];
- if ($s eq 'Debug' or $s eq 'Debugcolor') {
- setcolor() if $s eq 'Debugcolor';
- ${^RE_DEBUG_FLAGS} = 0 unless defined ${^RE_DEBUG_FLAGS};
- for my $idx ($idx+1..$#_) {
- if ($flags{$_[$idx]}) {
- if ($on) {
- ${^RE_DEBUG_FLAGS} |= $flags{$_[$idx]};
- } else {
- ${^RE_DEBUG_FLAGS} &= ~ $flags{$_[$idx]};
- }
- } else {
- require Carp;
- Carp::carp("Unknown \"re\" Debug flag '$_[$idx]', possible flags: ",
- join(", ",sort { $flags{$a} <=> $flags{$b} } keys %flags ) );
- }
- }
- _load_unload($on ? 1 : ${^RE_DEBUG_FLAGS});
- last;
- } elsif ($s eq 'debug' or $s eq 'debugcolor') {
- setcolor() if $s eq 'debugcolor';
- _load_unload($on);
- } elsif (exists $bitmask{$s}) {
- $bits |= $bitmask{$s};
- } else {
- require Carp;
- Carp::carp("Unknown \"re\" subpragma '$s' (known ones are: ",
- join(', ', map {qq('$_')} 'debug', 'debugcolor', sort keys %bitmask),
- ")");
- }
- }
- $bits;
-}
+ if (regexp_pattern($ref) eq '(?i-xsm:foo)')
-sub import {
- shift;
- $^H |= bits(1, @_);
-}
+will be warning free regardless of what $ref actually is.
-sub unimport {
- shift;
- $^H &= ~ bits(0, @_);
-}
+Like C<is_regexp> this function will not be confused by overloading
+or blessing of the object.
-1;
+=item regmust($ref)
+
+If the argument is a compiled regular expression as returned by C<qr//>,
+then this function returns what the optimiser considers to be the longest
+anchored fixed string and longest floating fixed string in the pattern.
+
+A I<fixed string> is defined as being a substring that must appear for the
+pattern to match. An I<anchored fixed string> is a fixed string that must
+appear at a particular offset from the beginning of the match. A I<floating
+fixed string> 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,
+
+ my $qr = qr/here .* there/x;
+ my ($anchored, $floating) = regmust($qr);
+ print "anchored:'$anchored'\nfloating:'$floating'\n";
+
+results in
+
+ anchored:'here'
+ floating:'there'
+
+Because the C<here> is before the C<.*> in the pattern, its position
+can be determined exactly. That's not true, however, for the C<there>;
+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.
+
+B<NOTE:> 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 L<perlbug> utility.
+
+=item regname($name,$all)
+
+Returns the contents of a named buffer of the last successful match. If
+$all is true, then returns an array ref containing one entry per buffer,
+otherwise returns the first defined buffer.
+
+=item regnames($all)
+
+Returns a list of all of the named buffers defined in the last successful
+match. If $all is true, then it returns all names defined, if not it returns
+only names which were involved in the match.
+
+=item regnames_count()
+
+Returns the number of distinct names defined in the pattern used
+for the last successful match.
+
+B<Note:> this result is always the actual number of distinct
+named buffers defined, it may not actually match that which is
+returned by C<regnames()> and related routines when those routines
+have not been called with the $all parameter set.
+
+=back
+
+=head1 SEE ALSO
+
+L<perlmodlib/Pragmatic Modules>.
+
+=cut