/ 
File-Next-1.04
River stage two • 20 direct dependents • 35 total dependents
/ File::Next

NAME

File::Next - File-finding iterator

VERSION

Version 1.04

SYNOPSIS

File::Next is a lightweight, taint-safe file-finding module. It's lightweight and has no non-core prerequisites.

use File::Next;

my $files = File::Next::files( '/tmp' );

while ( defined ( my $file = $files->() ) ) {
    # do something...
}

OPERATIONAL THEORY

The two major functions, files() and dirs(), return an iterator that will walk through a directory tree. The simplest use case is:

use File::Next;

my $iter = File::Next::files( '/tmp' );

while ( defined ( my $file = $iter->() ) ) {
    print $file, "\n";
}

# Prints...
/tmp/foo.txt
/tmp/bar.pl
/tmp/baz/1
/tmp/baz/2.txt
/tmp/baz/wango/tango/purple.txt

Note that only files are returned by files()'s iterator. Directories are ignored.

In list context, the iterator returns a list containing $dir, $file and $fullpath, where $fullpath is what would get returned in scalar context.

The first parameter to any of the iterator factory functions may be a hashref of options.

ITERATORS

For the three iterators, the \%options are optional.

files( [ \%options, ] @starting_points )

Returns an iterator that walks directories starting with the items in @starting_points. Each call to the iterator returns another regular file.

dirs( [ \%options, ] @starting_points )

Returns an iterator that walks directories starting with the items in @starting_points. Each call to the iterator returns another directory.

everything( [ \%options, ] @starting_points )

Returns an iterator that walks directories starting with the items in @starting_points. Each call to the iterator returns another file, whether it's a regular file, directory, symlink, socket, or whatever.

SUPPORT FUNCTIONS

sort_standard( $a, $b )

A sort function for passing as a sort_files option:

my $iter = File::Next::files( {
    sort_files => \&File::Next::sort_standard,
}, 't/swamp' );

This function is the default, so the code above is identical to:

my $iter = File::Next::files( {
    sort_files => 1,
}, 't/swamp' );

sort_reverse( $a, $b )

Same as sort_standard, but in reverse.

reslash( $path )

Takes a path with all forward slashes and rebuilds it with whatever is appropriate for the platform. For example 'foo/bar/bat' will become 'foo\bar\bat' on Windows.

This is really just a convenience function. I'd make it private, but ack wants it, too.

CONSTRUCTOR PARAMETERS

file_filter -> \&file_filter

The file_filter lets you check to see if it's really a file you want to get back. If the file_filter returns a true value, the file will be returned; if false, it will be skipped.

The file_filter function takes no arguments but rather does its work through a collection of variables.

  • $_ is the current filename within that directory

  • $File::Next::dir is the current directory name

  • $File::Next::name is the complete pathname to the file

These are analogous to the same variables in File::Find.

my $iter = File::Next::files( { file_filter => sub { /\.txt$/ } }, '/tmp' );

By default, the file_filter is sub {1}, or "all files".

This filter has no effect if your iterator is only returning directories.

descend_filter => \&descend_filter

The descend_filter lets you check to see if the iterator should descend into a given directory. Maybe you want to skip CVS and .svn directories.

my $descend_filter = sub { $_ ne "CVS" && $_ ne ".svn" }

The descend_filter function takes no arguments but rather does its work through a collection of variables.

  • $_ is the current filename of the directory

  • $File::Next::dir is the complete directory name

The descend filter is NOT applied to any directory names specified in as @starting_points in the constructor. For example,

my $iter = File::Next::files( { descend_filter => sub{0} }, '/tmp' );

always descends into /tmp, as you would expect.

By default, the descend_filter is sub {1}, or "always descend".

error_handler => \&error_handler

If error_handler is set, then any errors will be sent through it. By default, this value is CORE::die.

sort_files => [ 0 | 1 | \&sort_sub]

If you want files sorted, pass in some true value, as in sort_files => 1.

If you want a special sort order, pass in a sort function like sort_files => sub { $a->[1] cmp $b->[1] }. Note that the parms passed in to the sub are arrayrefs, where $a->[0] is the directory name, $a->[1] is the file name and $a->[2] is the full path. Typically you're going to be sorting on $a->[2].

If set to false, the iterator will ignore any files and directories that are actually symlinks. This has no effect on non-Unixy systems such as Windows. By default, this is true.

Note that this filter does not apply to any of the @starting_points passed in to the constructor.

You should not set follow_symlinks => 0 unless you specifically need that behavior. Setting follow_symlinks => 0 can be a speed hit, because File::Next must check to see if the file or directory you're about to follow is actually a symlink.

PRIVATE FUNCTIONS

_setup( $default_parms, @whatever_was_passed_to_files() )

Handles all the scut-work for setting up the parms passed in.

Returns a hashref of operational options, combined between $passed_parms and $defaults, plus the queue.

The queue prep stuff takes the strings in @starting_points and puts them in the format that queue needs.

The @queue that gets passed around is an array that has three elements for each of the entries in the queue: $dir, $file and $fullpath. Items must be pushed and popped off the queue three at a time (spliced, really).

_candidate_files( $parms, $dir )

Pulls out the files/dirs that might be worth looking into in $dir. If $dir is the empty string, then search the current directory.

$parms is the hashref of parms passed into File::Next constructor.

SPEED TWEAKS

  • Don't set follow_symlinks => 0 unless you need it.

AUTHOR

Andy Lester, <andy at petdance.com>

BUGS

Please report any bugs or feature requests to http://github.com/petdance/file-next/issues.

Note that File::Next does NOT use http://rt.cpan.org for bug tracking.

SUPPORT

You can find documentation for this module with the perldoc command.

perldoc File::Next

You can also look for information at:

ACKNOWLEDGEMENTS

All file-finding in this module is adapted from Mark Jason Dominus' marvelous Higher Order Perl, page 126.

COPYRIGHT & LICENSE

Copyright 2005-2009 Andy Lester.

This program is free software; you can redistribute it and/or modify it under the terms of either:

  • the GNU General Public License as published by the Free Software Foundation; either version 1, or (at your option) any later version, or

  • the Artistic License version 2.0.

1; # End of File::Next