Path::Class::Each - Iterate lines in a file
This document describes Path::Class::Each version 0.03
use Path::Class; use Path::Class::Each; ## Files ## # Iterator interface my $iter = file( 'foo', 'bar' )->iterator; while ( defined( my $line = $iter->() ) ) { print "Line: $line\n"; } # 'next' interface my $file = file( 'foo', 'bar' ); while ( defined( my $line = $file->next ) ) { print "Line: $line\n"; } # Callback interface file( 'foo', 'bar' )->each( sub { print "Line: $_\n"; } ); ## Directories ## # Iterator interface my $iter = dir( 'foo', 'bar' )->iterator; while ( defined( my $file = $iter->() ) ) { print "File: $file\n"; } # 'next' interface my $file = dir( 'foo', 'bar' ); while ( defined( my $file = $dir->next_file ) ) { print "File: $file\n"; } # Callback interface dir( 'foo', 'bar' )->each( sub { print "File: $_\n"; } );
Path::Class::Each augments Path::Class::File and Path::Class::Dir to provide three different ways of iterating over the lines of a file and three ways of iterating the files recursively contained in a directory.
Path::Class::Each
Path::Class::File provides a slurp method that returns the contents of a file (either as a scalar or an array) but has no support for reading a file a line at a time. For large files it may be desirable to iterate through the lines; that's where this module comes in.
Path::Class::File
slurp
Path::Class::Dir provides children which returns the files and directories immediately contained in a directory but does not expose a 'find' interface to recursively search a directory. This module provides iterators that visit all the files in the directory tree below a directory.
Path::Class::Dir
children
Path::Class::File->iterator
Get an iterator that returns the lines in a file. Returns undef when there are no more lines to return.
undef
my $iter = file( 'foo', 'bar' )->iterator; while ( defined( my $line = $iter->() ) ) { print "Line: $line\n"; }
If the file can not be opened an exception will be thrown (using croak).
croak
The following options may be passed as key, value pairs:
chomp
Newlines will be trimmed from each line read.
iomode
Passed as the mode argument to open. See Path::Class::File::open for details. If omitted defaults to 'r' (read-only).
mode
open
Here's how options are passed:
my $chomper = file('foo', 'bar')->iterator( chomp => 1 );
Path::Class::File->next
Return the next line from a file. Returns undef when all lines have been read.
Internally iterator is called if necessary to create a new iterator. The same options that iterator accepts may be passed to next:
next
my $file = file( 'foo', 'bar' ); while ( defined( my $line = $file->next( chomp => 1 ) ) ) { print "Line: $line\n"; }
It may be tempting to use an idiom like:
# DON'T DO THIS while ( my $line = file('foo')->next ) { ... }
That will create a new Path::Class::File and, therefore, a new iterator each time it is called with the result that the first line of the file will be returned repeatedly.
Path::Class::File->each
Call a supplied callback for each line in a file. The same options that iterator accepts may be passed:
file( 'foo', 'bar' )->each( chomp => 1, sub { print "Line: $_\n" } );
Within the callback the current line will be in $_.
$_
Path::Class::Dir->iterator
Return an iterator that returns each of the files in and below a directory.
By default only files are returned. The following options may be supplied to modify this behaviour:
dirs
Return directories as well as files.
no_files
Return directories only.
Path::Class::Dir->next_file
Return the next file from a recursive search of a directory. Returns undef when all lines have been read.
Internally iterator is called if necessary to create a new iterator. The same options that iterator accepts may be passed to next_file:
next_file
my $dir = dir( 'foo', 'bar' ); while ( defined( my $file = $dir->next_file ) ) { print "File: $file\n"; }
Path::Class::Dir->next_dir
Return the next directory from a recursive search of a directory.
Path::Class::Dir->each
Call a supplied callback for each file in a directory. The same options that iterator accepts may be passed:
dir( 'foo', 'bar' )->each( dirs => 1, sub { print "Object: $_\n" } );
Within the callback the current file will be in $_.
Path::Class::Dir->each_dir
Call a supplied callback for each subdirectory in a directory.
Path::Class
Andy Armstrong <andy@hexten.net>
<andy@hexten.net>
Copyright (c) 2010, Andy Armstrong <andy@hexten.net>. All rights reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. See perlartistic.
BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR, OR CORRECTION.
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To install Path::Class::Each, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Path::Class::Each
CPAN shell
perl -MCPAN -e shell install Path::Class::Each
For more information on module installation, please visit the detailed CPAN module installation guide.