table of contents
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/^#!.*\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:
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 =~ /^#!.*\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
2021-08-09 | perl v5.32.1 |