File::Find::Rule(3pm) User Contributed Perl Documentation File::Find::Rule(3pm)
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 v5.12.4 2011-09-20 File::Find::Rule(3pm)