dosglob.pm

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.

# _un_escape() will only be used on Mac OS (Classic):
# Unescapes a list of arguments which may contain escaped 
# metachars '*', '?' and '\'.
#
sub _un_escape {
	foreach (@_) {
		s/\\([*?\\])/$1/g;
	}
	return @_;
}

#
# this can be used to override CORE::glob in a specific
# package by saying C<use File::DosGlob 'glob';> in that
# namespace.
#

# context (keyed by second cxix arg provided by core)
my %iter;
my %entries;

sub glob {
    my($pat,$cxix) = @_;
    my @pat;

    # glob without args defaults to $_
    $pat = $_ unless defined $pat;

    # extract patterns
    if ($pat =~ /\s/) {
	require Text::ParseWords;
	@pat = Text::ParseWords::parse_line('\s+',0,$pat);
    }
    else {
	push @pat, $pat;
    }

    # Mike Mestnik: made to do abc{1,2,3} == abc1 abc2 abc3.
    #   abc3 will be the original {3} (and drop the {}).
    #   abc1 abc2 will be put in @appendpat.
    # This was just the esiest way, not nearly the best.
    REHASH: {
	my @appendpat = ();
	for (@pat) {
	    # There must be a "," I.E. abc{efg} is not what we want.
	    while ( /^(.*)(?<!\\)\{(.*?)(?<!\\)\,.*?(?<!\\)\}(.*)$/ ) {
		my ($start, $match, $end) = ($1, $2, $3);
		#print "Got: \n\t$start\n\t$match\n\t$end\n";
		my $tmp = "$start$match$end";
		while ( $tmp =~ s/^(.*?)(?<!\\)\{(?:.*(?<!\\)\,)?(.*\Q$match\E.*?)(?:(?<!\\)\,.*)?(?<!\\)\}(.*)$/$1$2$3/ ) {
		    #print "Striped: $tmp\n";
		    #  these expanshions will be preformed by the original,
		    #  when we call REHASH.
		}
		push @appendpat, ("$tmp");
		s/^\Q$start\E(?<!\\)\{\Q$match\E(?<!\\)\,/$start\{/;
		if ( /^\Q$start\E(?<!\\)\{(?!.*?(?<!\\)\,.*?\Q$end\E$)(.*)(?<!\\)\}\Q$end\E$/ ) {
		    $match = $1;
		    #print "GOT: \n\t$start\n\t$match\n\t$end\n\n";
		    $_ = "$start$match$end";
		}
	    }
	    #print "Sould have "GOT" vs "Got"!\n";
		#FIXME: There should be checking for this.
		#  How or what should be done about failure is beond me.
	}
	if ( $#appendpat != -1
		) {
	    #print "LOOP\n";
	    #FIXME: Max loop, no way! :")
	    for ( @appendpat ) {
	        push @pat, $_;
	    }
	    goto REHASH;
	}
    }
    for ( @pat ) {
	s/\\{/{/g;
	s/\\}/}/g;
	s/\\,/,/g;
    }
    #print join ("\n", @pat). "\n";
 
    # assume global context if not provided one
    $cxix = '_G_' unless defined $cxix;
    $iter{$cxix} = 0 unless exists $iter{$cxix};

    # if we're just beginning, do it all first
    if ($iter{$cxix} == 0) {
	if ($^O eq 'MacOS') {
		# first, take care of updirs and trailing colons
		@pat = _preprocess_pattern(@pat);
		# expand volume names
		@pat = _expand_volume(@pat);
		$entries{$cxix} = (@pat) ? [_un_escape( doglob_Mac(1,@pat) )] : [()];
	} else {
		$entries{$cxix} = [doglob(1,@pat)];
    }
	}

    # chuck it all out, quick or slow
    if (wantarray) {
	delete $iter{$cxix};
	return @{delete $entries{$cxix}};
    }
    else {
	if ($iter{$cxix} = scalar @{$entries{$cxix}}) {
	    return shift @{$entries{$cxix}};
	}
	else {
	    # return undef for EOL
	    delete $iter{$cxix};
	    delete $entries{$cxix};
	    return undef;
	}
    }
}

{
    no strict 'refs';

    sub import {
    my $pkg = shift;
    return unless @_;
    my $sym = shift;
    my $callpkg = ($sym =~ s/^GLOBAL_//s ? 'CORE::GLOBAL' : caller(0));
    *{$callpkg.'::'.$sym} = \&{$pkg.'::'.$sym} if $sym eq 'glob';
    }
}
1;

__END__

=head1 NAME

File::DosGlob - DOS like globbing and then some

=head1 SYNOPSIS

    require 5.004;

    # override CORE::glob in current package
    use File::DosGlob 'glob';

    # override CORE::glob in ALL packages (use with extreme caution!)
    use File::DosGlob 'GLOBAL_glob';

    @perlfiles = glob  "..\\pe?l/*.p?";
    print <..\\pe?l/*.p?>;

    # from the command line (overrides only in main::)
    > perl -MFile::DosGlob=glob -e "print <../pe*/*p?>"

=head1 DESCRIPTION

A module that implements DOS-like globbing with a few enhancements.
It is largely compatible with perlglob.exe (the M$ setargv.obj
version) in all but one respect--it understands wildcards in
directory components.

For example, C<<..\\l*b\\file/*glob.p?>> will work as expected (in
that it will find something like '..\lib\File/DosGlob.pm' alright).
Note that all path components are case-insensitive, and that
backslashes and forward slashes are both accepted, and preserved.
You may have to double the backslashes if you are putting them in
literally, due to double-quotish parsing of the pattern by perl.

Spaces in the argument delimit distinct patterns, so
C<glob('*.exe *.dll')> globs all filenames that end in C<.exe>
or C<.dll>.  If you want to put in literal spaces in the glob
pattern, you can escape them with either double quotes, or backslashes.
e.g. C<glob('c:/"Program Files"/*/*.dll')>, or
C<glob('c:/Program\ Files/*/*.dll')>.  The argument is tokenized using
C<Text::ParseWords::parse_line()>, so see L<Text::ParseWords> for details
of the quoting rules used.

Extending it to csh patterns is left as an exercise to the reader.

=head1 NOTES

=over 4

=item *

Mac OS (Classic) users should note a few differences. The specification 
of pathnames in glob patterns adheres to the usual Mac OS conventions: 
The path separator is a colon ':', not a slash '/' or backslash '\'. A 
full path always begins with a volume name. A relative pathname on Mac 
OS must always begin with a ':', except when specifying a file or 
directory name in the current working directory, where the leading colon 
is optional. If specifying a volume name only, a trailing ':' is 
required. Due to these rules, a glob like E<lt>*:E<gt> will find all 
mounted volumes, while a glob like E<lt>*E<gt> or E<lt>:*E<gt> will find 
all files and directories in the current directory.

Note that updirs in the glob pattern are resolved before the matching begins,
i.e. a pattern like "*HD:t?p::a*" will be matched as "*HD:a*". Note also,
that a single trailing ':' in the pattern is ignored (unless it's a volume
name pattern like "*HD:"), i.e. a glob like <:*:> will find both directories 
I<and> files (and not, as one might expect, only directories). 

The metachars '*', '?' and the escape char '\' are valid characters in 
volume, directory and file names on Mac OS. Hence, if you want to match
a '*', '?' or '\' literally, you have to escape these characters. Due to 
perl's quoting rules, things may get a bit complicated, when you want to 
match a string like '\*' literally, or when you want to match '\' literally, 
but treat the immediately following character '*' as metachar. So, here's a 
rule of thumb (applies to both single- and double-quoted strings): escape 
each '*' or '?' or '\' with a backslash, if you want to treat them literally, 
and then double each backslash and your are done. E.g. 

- Match '\*' literally

   escape both '\' and '*'  : '\\\*'
   double the backslashes   : '\\\\\\*'

(Internally, the glob routine sees a '\\\*', which means that both '\' and 
'*' are escaped.)


- Match '\' literally, treat '*' as metachar

   escape '\' but not '*'   : '\\*'
   double the backslashes   : '\\\\*'

(Internally, the glob routine sees a '\\*', which means that '\' is escaped and 
'*' is not.)

Note that you also have to quote literal spaces in the glob pattern, as described
above.

=back

=head1 EXPORTS (by request only)

glob()

=head1 BUGS

Should probably be built into the core, and needs to stop
pandering to DOS habits.  Needs a dose of optimizium too.

=head1 AUTHOR

Gurusamy Sarathy <[e-mail]>

=head1 HISTORY

=over 4

=item *

Support for globally overriding glob() (GSAR 3-JUN-98)

=item *

Scalar context, independent iterator context fixes (GSAR 15-SEP-97)

=item *

A few dir-vs-file optimizations result in glob importation being
10 times faster than using perlglob.exe, and using perlglob.bat is
only twice as slow as perlglob.exe (GSAR 28-MAY-97)

=item *

Several cleanups prompted by lack of compatible perlglob.exe
under Borland (GSAR 27-MAY-97)

=item *

Initial version (GSAR 20-FEB-97)

=back

=head1 SEE ALSO

perl

perlglob.bat

Text::ParseWords

=cut