NAME

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

SYNOPSIS

# 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/^#!.*\bperl/, [ 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

canonpath

Normalize paths found using File::Spec-canonpath>. This will return paths with a file-seperator that is native to your OS (as determined by File::Spec), instead of the default /.

For example, this will return tmp/foobar on Unix-ish OSes and tmp\foobar on Win32.

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:

# 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 =~ /^#!.*\bperl/;
}
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