File::Find::Rule(3)					User Contributed Perl Documentation				       File::Find::Rule(3)

NAME

       File::Find::Rule - Alternative interface to File::Find

SYNOPSIS

	 use File::Find::Rule;
	 # find all the subdirectories of a given directory
	 my @subdirs = File::Find::Rule->directory->in( $directory );

	 # find all the .pm files in @INC
	 my @files = File::Find::Rule->file()
				     ->name( '*.pm' )
				     ->in( @INC );

	 # as above, but without method chaining
	 my $rule =  File::Find::Rule->new;
	 $rule->file;
	 $rule->name( '*.pm' );
	 my @files = $rule->in( @INC );

DESCRIPTION

       File::Find::Rule is a friendlier interface to File::Find.  It allows you to build rules which specify the desired files and directories.

METHODS

       "new"
	   A constructor.  You need not invoke "new" manually unless you wish to, as each of the rule-making methods will auto-create a suitable
	   object if called as class methods.

   Matching Rules
       "name( @patterns )"
	   Specifies names that should match.  May be globs or regular expressions.

	    $set->name( '*.mp3', '*.ogg' ); # mp3s or oggs
	    $set->name( qr/.(mp3|ogg)$/ ); # the same as a regex
	    $set->name( 'foo.bar' );	    # just things named foo.bar

       -X tests
	   Synonyms are provided for each of the -X tests. See "-X" in perlfunc for details.  None of these methods take arguments.

	     Test | Method		 Test |  Method
	    ------|-------------	------|----------------
	      -r  |  readable		  -R  |  r_readable
	      -w  |  writeable		  -W  |  r_writeable
	      -w  |  writable		  -W  |  r_writable
	      -x  |  executable 	  -X  |  r_executable
	      -o  |  owned		  -O  |  r_owned
		  |			      |
	      -e  |  exists		  -f  |  file
	      -z  |  empty		  -d  |  directory
	      -s  |  nonempty		  -l  |  symlink
		  |			  -p  |  fifo
	      -u  |  setuid		  -S  |  socket
	      -g  |  setgid		  -b  |  block
	      -k  |  sticky		  -c  |  character
		  |			  -t  |  tty
	      -M  |  modified		      |
	      -A  |  accessed		  -T  |  ascii
	      -C  |  changed		  -B  |  binary

	   Though some tests are fairly meaningless as binary flags ("modified", "accessed", "changed"), they have been included for completeness.

	    # find nonempty files
	    $rule->file,
		 ->nonempty;

       stat tests
	   The following "stat" based methods are provided: "dev", "ino", "mode", "nlink", "uid", "gid", "rdev", "size", "atime", "mtime",
	   "ctime", "blksize", and "blocks".  See "stat" in perlfunc for details.

	   Each of these can take a number of targets, which will follow Number::Compare semantics.

	    $rule->size( 7 );	      # exactly 7
	    $rule->size( ">7Ki" );    # larger than 7 * 1024 * 1024 bytes
	    $rule->size( ">=7" )
		 ->size( "<=90" );    # between 7 and 90, inclusive
	    $rule->size( 7, 9, 42 );  # 7, 9 or 42

       "any( @rules )"
       "or( @rules )"
	   Allows shortcircuiting boolean evaluation as an alternative to the default and-like nature of combined rules.  "any" and "or" are
	   interchangeable.

	    # find avis, movs, things over 200M and empty files
	    $rule->any( File::Find::Rule->name( '*.avi', '*.mov' ),
			File::Find::Rule->size( '>200M' ),
			File::Find::Rule->file->empty,
		      );

       "none( @rules )"
       "not( @rules )"
	   Negates a rule.  (The inverse of "any".)  "none" and "not" are interchangeable.

	     # files that aren't 8.3 safe
	     $rule->file
		  ->not( $rule->new->name( qr/^[^.]{1,8}(.[^.]{0,3})?$/ ) );

       "prune"
	   Traverse no further.  This rule always matches.

       "discard"
	   Don't keep this file.  This rule always matches.

       "exec( &subroutine( $shortname, $path, $fullname ) )"
	   Allows user-defined rules.  Your subroutine will be invoked with $_ set to the current short name, and with parameters of the name, the
	   path you're in, and the full relative filename.

	   Return a true value if your rule matched.

	    # get things with long names
	    $rules->exec( sub { length > 20 } );

       "grep( @specifiers )"
	   Opens a file and tests it each line at a time.

	   For each line it evaluates each of the specifiers, stopping at the first successful match.  A specifier may be a regular expression or
	   a subroutine.  The subroutine will be invoked with the same parameters as an ->exec subroutine.

	   It is possible to provide a set of negative specifiers by enclosing them in anonymous arrays.  Should a negative specifier match the
	   iteration is aborted and the clause is failed.  For example:

	    $rule->grep( qr/^#!.*perl/, [ sub { 1 } ] );

	   Is a passing clause if the first line of a file looks like a perl shebang line.

       "maxdepth( $level )"
	   Descend at most $level (a non-negative integer) levels of directories below the starting point.

	   May be invoked many times per rule, but only the most recent value is used.

       "mindepth( $level )"
	   Do not apply any tests at levels less than $level (a non-negative integer).

       "extras( \%extras )"
	   Specifies extra values to pass through to "File::File::find" as part of the options hash.

	   For example this allows you to specify following of symlinks like so:

	    my $rule = File::Find::Rule->extras({ follow => 1 });

	   May be invoked many times per rule, but only the most recent value is used.

       "relative"
	   Trim the leading portion of any path found

       "not_*"
	   Negated version of the rule.  An effective shortand related to ! in the procedural interface.

	    $foo->not_name('*.pl');

	    $foo->not( $foo->new->name('*.pl' ) );

   Query Methods
       "in( @directories )"
	   Evaluates the rule, returns a list of paths to matching files and directories.

       "start( @directories )"
	   Starts a find across the specified directories.  Matching items may then be queried using "match".  This allows you to use a rule as an
	   iterator.

	    my $rule = File::Find::Rule->file->name("*.jpeg")->start( "/web" );
	    while ( defined ( my $image = $rule->match ) ) {
		...
	    }

       "match"
	   Returns the next file which matches, false if there are no more.

   Extensions
       Extension modules are available from CPAN in the File::Find::Rule namespace.  In order to use these extensions either use them directly:

	use File::Find::Rule::ImageSize;
	use File::Find::Rule::MMagic;

	# now your rules can use the clauses supplied by the ImageSize and
	# MMagic extension

       or, specify that File::Find::Rule should load them for you:

	use File::Find::Rule qw( :ImageSize :MMagic );

       For notes on implementing your own extensions, consult File::Find::Rule::Extending

   Further examples
       Finding perl scripts
	    my $finder = File::Find::Rule->or
	     (
	      File::Find::Rule->name( '*.pl' ),
	      File::Find::Rule->exec(
				     sub {
					 if (open my $fh, $_) {
					     my $shebang = <$fh>;
					     close $fh;
					     return $shebang =~ /^#!.*perl/;
					 }
					 return 0;
				     } ),
	     );

	   Based upon this message http://use.perl.org/comments.pl?sid=7052&cid=10842

       ignore CVS directories
	    my $rule = File::Find::Rule->new;
	    $rule->or($rule->new
			   ->directory
			   ->name('CVS')
			   ->prune
			   ->discard,
		      $rule->new);

	   Note here the use of a null rule.  Null rules match anything they see, so the effect is to match (and discard) directories called 'CVS'
	   or to match anything.

TWO FOR THE PRICE OF ONE

       File::Find::Rule also gives you a procedural interface.	This is documented in File::Find::Rule::Procedural

EXPORTS

       "find", "rule"

TAINT MODE INTERACTION

       As of 0.32 File::Find::Rule doesn't capture the current working directory in a taint-unsafe manner.  File::Find itself still does
       operations that the taint system will flag as insecure but you can use the "extras" feature to ask File::Find to internally "untaint" file
       paths with a regex like so:

	   my $rule = File::Find::Rule->extras({ untaint => 1 });

       Please consult File::Find's documentation for "untaint", "untaint_pattern", and "untaint_skip" for more information.

BUGS

       The code makes use of the "our" keyword and as such requires perl version 5.6.0 or newer.

       Currently it isn't possible to remove a clause from a rule object.  If this becomes a significant issue it will be addressed.

AUTHOR

       Richard Clamp <richardc@unixbeard.net> with input gained from this use.perl discussion: http://use.perl.org/~richardc/journal/6467

       Additional proofreading and input provided by Kake, Greg McCarroll, and Andy Lester andy@petdance.com.

COPYRIGHT

       Copyright (C) 2002, 2003, 2004, 2006, 2009, 2011 Richard Clamp.	All Rights Reserved.

       This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

SEE ALSO

       File::Find, Text::Glob, Number::Compare, find(1)

       If you want to know about the procedural interface, see File::Find::Rule::Procedural, and if you have an idea for a neat extension
       File::Find::Rule::Extending

perl v5.16.2							    2011-09-19						       File::Find::Rule(3)