Provided by: libfile-util-perl_4.201720-2_all 
NAME
File::Util - Easy, versatile, portable file handling
VERSION
version 4.201720
DESCRIPTION
File::Util provides a comprehensive toolbox of utilities to automate all kinds of common
tasks on files and directories. Its purpose is to do so in the most portable manner
possible so that users of this module won't have to worry about whether their programs
will work on other operating systems and/or architectures. It works on Linux, Windows,
Mac, BSD, Unix and others.
File::Util is written purely in Perl, and requires no compiler or make utility on your
system in order to install and run it. It loads a minimal amount of code when used, only
pulling in support for lesser-used methods on demand. It has no dependencies other than
what comes installed with Perl itself.
File::Util also aims to be as backward compatible as possible, running without problems on
Perl installations as old as 5.006. You are encouraged to run File::Util on Perl version
5.8 and above.
After browsing this document, please have a look at the other documentation. (See
DOCUMENTATION section below.)
SYNOPSIS
# use File::Util in your program
use File::Util;
# create a new File::Util object
my $f = File::Util->new();
# read file into a variable
my $content = $f->load_file( 'some_file.txt' );
# write content to a file
$f->write_file( 'some_other_file.txt' => 'Hello world!' );
# get the contents of a directory, 3 levels deep
my @songs = $f->list_dir( '~/Music' => { recurse => 1, max_depth => 3 } );
DOCUMENTATION
You can do much more with File::Util than the examples above. For an explanation of all
the features available to you, take a look at these other reference materials:
Examples
The File::Util::Manual::Examples document has a long list of small, reusable code
snippets and techniques to use in your own programs. This is the "cheat sheet", and
is a great place to get started quickly. Almost everything you need is here.
Complete API Reference
The File::Util::Manual is the complete reference document explaining every available
feature and object method. Use this to look up the full information on any given
feature when the examples aren't enough.
Cookbook
The File::Util::Cookbook contains examples of complete, working programs that use
File::Util to easily accomplish tasks which require file handling.
BASIC USAGE
Getting Started
# use File::Util in your program
use File::Util;
# ...you can optionally enable File::Util's diagnostic error messages:
# (see File::Util::Manual section regarding diagnostics)
use File::Util qw( :diag );
# create a new File::Util object
my $f = File::Util->new();
# ...you can enable diagnostics for individual objects:
$f = File::Util->new( diag => 1 );
File Operations
# load file content into a scalar variable as raw text
my $content = $f->load_file( 'somefile.txt' );
# read a binary file the same way
my $binary_content = $f->load_file( 'barking-cat.mp4' );
# write a raw text file
$f->write_file( 'somefile.txt' => $content );
# ...and write a binary file, using some other options as well
$f->write_file(
'llama.jpg' => $picture_data => { binmode => 1, bitmask => oct 644 }
);
# ...or write a file with UTF-8 encoding (unicode support)
$f->write_file( 'encoded.txt' => qq(\x{c0}) => { binmode => 'utf8' } );
# load a file into an array, line by line
my @lines = $f->load_file( 'file.txt' => { as_lines => 1 } );
# see if you have permission to write to a file, then append to it
if ( $f->is_writable( 'captains.log' ) ) {
my $fh = $f->open_handle( 'captains.log' => 'append' );
print $fh "Captain's log, stardate 41153.7. Our destination is...";
close $fh or die $!;
}
else { # ...or warn the crew
warn "Trouble on the bridge, the Captain can't access his log!";
}
# get the number of lines in a file
my $log_line_count = $f->line_count( '/var/log/messages' );
File Handles
# get an open file handle for reading
my $fh = $f->open_handle( 'Ian likes cats.txt' => 'read' );
while ( my $line = <$fh> ) { # read the file, line by line
# ... do stuff
}
# get an open file handle for writing the same way
$fh = $f->open_handle( 'John prefers dachshunds.txt' => 'write' );
# You add the option to turn on UTF-8 strict encoding for your reads/writes
$fh = $f->open_handle(
'John prefers dachshunds.txt' => 'write' => { binmode => 'utf8' }
);
print $fh "Bob is happy! \N{U+263A}"; # << unicode smiley face!
# you can use sysopen to get low-level with your file handles if needed
$fh = $f->open_handle(
'alderaan.txt' => 'rwclobber' => { use_sysopen => 1 }
);
syswrite $fh, "that's no moon";
# ...You can use any of these syswrite modes with open_handle():
# read, write, append, rwcreate, rwclobber, rwappend, rwupdate, and trunc
PLEASE NOTE that as of Perl 5.23, it is deprecated to mix system IO
(sysopen/syswrite/sysread/sysseek) with utf8 binmode (see perldoc perlport). As such,
File::Util will no longer allow you to do this after version 4.132140. Please see notes
on UTF-8 and encoding further below.
# ...THIS WILL NOW FAIL!
$f->open_handle(
'somefile.txt' => 'write' => { use_sysopen => 1, binmode => 'utf8' }
);
Directories
# get a listing of files, recursively, skipping directories
my @files = $f->list_dir( '/var/tmp' => { files_only => 1, recurse => 1 } );
# get a listing of text files, recursively
my @textfiles = $f->list_dir(
'/var/tmp' => {
files_match => qr/\.txt$/,
files_only => 1,
recurse => 1,
}
);
# walk a directory, using an anonymous function or function ref as a callback
$f->list_dir( '/home/larry' => {
recurse => 1,
callback => sub {
my ( $selfdir, $subdirs, $files ) = @_;
# do stuff ...
},
} );
# get an entire directory tree as a hierarchal datastructure reference
my $tree = $f->list_dir( '/my/podcasts' => { as_tree => 1 } );
Getting Information About Files
print 'My file has a bitmask of ' . $f->bitmask( 'my.file' );
print 'My file is a ' . join(', ', $f->file_type( 'my.file' )) . " file.";
warn 'This file is binary!' if $f->is_bin( 'my.file' );
print 'My file was last modified on ' .
scalar localtime $f->last_modified( 'my.file' );
Getting Information About Your System's IO Capabilities
# Does your running Perl support unicode?
print 'I support unicode' if $f->can_utf8;
# Can your system use file locking?
print 'I can use flock' if $f->can_flock;
# The correct directory separator for your system
print 'The correct directory separator for this system is ' . $f->SL;
# Does your platform require binmode for all IO?
print 'I always need binmode' if $f->needs_binmode;
# Is your system an EBCDIC platform? (see perldoc perlebcdic)
print 'This is an EBCDIC platform, so be careful!' if $f->EBCDIC;
...See the File::Util::Manual for more details and features like advanced pattern matching
in directories, callbacks, directory walking, user-definable error handlers, and more.
File Encoding and UTF-8
If you want to read/write in UTF-8, you can do that:
$ftl->load_file( 'file.txt' => $content => { binmode => 'utf8' } );
$ftl->write_file( 'file.txt' => $content => { binmode => 'utf8' } );
$ftl->open_handle( 'file.txt' => 'read' => { binmode => 'utf8' } );
# ...and so on
Only use "binmode => 'utf8'" for text.
Encoding and IO layers (sometimes called disciplines) can become complex. It's not
something you usually need to worry about unless you wish to really fine tune File::Util's
behavior beyond what are very suitable, portable defaults, or accomplish very specific
tasks like encoding conversions.
You're free to specify any binmode you like, or allow File::Util to use the system's
default IO layering. It will automatically use the ":raw" pseudo layer when reading files
that are binary, unless specifically told to use something different.
You can control things as shown in the examples below:
$ftl->load_file( 'file.txt' => $content => { binmode => SPEC } );
$ftl->write_file( 'file.txt' => $content => { binmode => SPEC } );
$ftl->open_handle( 'file.txt' => 'read' => { binmode => SPEC } );
...where "SPEC" is one or more of any supported IO layers on your system. Examples might
include:
• ':raw'
• ':unix'
• ':crlf'
• ':stdio'
• ':encoding(ENCODING)' with ENCODING's like iso-8859-1, shiftjis, etc
• ...and much more
You can learn about the IO layers available to you and what they do in the PerlIO perldoc.
Available options have increased over the years, and are likely subject to continued
evolution. Consult the PerlIO and Encode documentation as your authoritative source of
info on what layers to use.
PERFORMANCE
File::Util consists of a set of smaller modules, but only loads the ones it needs when it
needs them. It offers a comparatively fast load-up time, so using File::Util doesn't
bloat your code's resource footprint.
Additionally, File::Util has been optimized to run fast. In many scenarios it does more
and still out-performs other popular IO modules. Benchmarking tools are included as part
of the File::Util installation package.
(See the benchmarking and profiling scripts that are included as part of this
distribution.)
METHODS
File::Util exposes the following public methods.
Each of which are covered in the File::Util::Manual, which has more room for the detailed
explanation that is provided there.
This is just an itemized table of contents for HTML POD readers. For those viewing this
document in a text terminal, open perldoc to the "File::Util::Manual".
atomize_path (see atomize_path)
bitmask (see bitmask)
can_flock (see can_flock)
can_utf8 (see can_utf8)
created (see created)
default_path (see default_path)
diagnostic (see diagnostic)
ebcdic (see ebcdic)
escape_filename (see escape_filename)
existent (see existent)
file_type (see file_type)
flock_rules (see flock_rules)
is_bin (see is_bin)
is_readable (see is_readable)
is_writable (see is_writable)
last_access (see last_access)
last_changed (see last_changed)
last_modified (see last_modified)
line_count (see line_count)
list_dir (see list_dir)
load_dir (see load_dir)
load_file (see load_file)
make_dir (see make_dir)
abort_depth (see abort_depth)
needs_binmode (see needs_binmode)
new (see new)
onfail (see onfail)
open_handle (see open_handle)
read_limit (see read_limit)
return_path (see return_path)
size (see size)
split_path (see split_path)
strict_path (see strict_path)
strip_path (see strip_path)
touch (see touch)
trunc (see trunc)
unlock_open_handle (see unlock_open_handle)
use_flock (see use_flock)
valid_filename (see valid_filename)
write_file (see write_file)
EXPORTED SYMBOLS
Exports nothing by default. File::Util fully respects your namespace. You can, however,
ask it for certain things (below).
EXPORT_OK
The following symbols comprise @File::Util::EXPORT_OK, and as such are available for
import to your namespace only upon request. They can be used either as object methods or
like regular subroutines in your program.
- atomize_path - can_flock - can_utf8
- created - default_path - diagnostic
- ebcdic - escape_filename - existent
- file_type - is_bin - is_readable
- is_writable - last_access - last_changed
- last_modified - needs_binmode - strict_path
- return_path - size - split_path
- strip_path - valid_filename - NL and S L
To get any of these functions/symbols into your namespace without having to use them as
object methods, use this kind of syntax:
use File::Util qw( strip_path return_path existent size );
my $file = $ARGV[0];
my $fname = strip_path( $file );
my $path = return_path( $file );
my $size = size( $file );
print qq(File "$fname" exists in "$path", and is $size bytes in size)
if existent( $file );
EXPORT_TAGS
:all (imports all of @File::Util::EXPORT_OK to your namespace)
:diag (imports nothing to your namespace, it just enables diagnostics)
You can use these tags alone, or in combination with other symbols as shown above.
PREREQUISITES
None. There are no external prerequisite modules.
File::Util only depends on modules that are part of the Core Perl distribution, and
you don't need a compiler on your system to install it.
File::Util recommends Perl 5.8.1 or better ...
You can technically run File::Util on older versions of Perl 5, but it isn't
recommended, especially if you want unicode support and wish to take advantage of
File::Util's ability to read and write files using UTF-8 encoding.
Unicode::UTF8 is also recommended and helps speed things up in several places where
you might choose to use unicode as described elsewhere in the File::Util::Manual.
INSTALLATION
To install this module type the following at the command prompt:
perl Build.PL
perl Build
perl Build test
sudo perl Build install
On Windows systems, the "sudo" part of the command may be omitted, but you will need to
run the rest of the install command with Administrative privileges
BUGS
Send bug reports and patches to the CPAN Bug Tracker for File::Util at rt.cpan.org
<https://rt.cpan.org/Dist/Display.html?Name=File%3A%3AUtil>
SUPPORT
If you want to get help, contact the authors (links below in AUTHORS section)
I fully endorse <http://www.perlmonks.org> as an excellent source of help with Perl in
general.
CONTRIBUTING
The project website for File::Util is at <https://github.com/tommybutler/file-util/wiki>
The git repository for File::Util is on Github at
<https://github.com/tommybutler/file-util>
Clone it at <git://github.com/tommybutler/file-util.git>
This project was a private endeavor for too long so don't hesitate to pitch in.
CONTRIBUTORS
The following people have contributed to File::Util in the form of feedback,
encouragement, recommendations, testing, or assistance with problems either on or offline
in one form or another. Listed in no particular order:
• John Fields <jfields.cpan.org@spammenot.com>
• BrowserUk <browseruk@cpan.org>
• Ricardo SIGNES <rjbs@cpan.org>
• Matt S Trout <perl-stuff@trout.me.uk>
• Nicholas Perez <nperez@cpan.org>
• David Golden <dagolden@cpan.org>
AUTHORS
Tommy Butler <http://www.atrixnet.com/contact>
Others Welcome!
COPYRIGHT
Copyright(C) 2001-2013, Tommy Butler. All rights reserved.
LICENSE
This library is free software, you may redistribute it and/or modify it under the same
terms as Perl itself. For more details, see the full text of the LICENSE file that is
included in this distribution.
LIMITATION OF WARRANTY
This software is distributed in the hope that it will be useful, but without any warranty;
without even the implied warranty of merchantability or fitness for a particular purpose.
This disclaimer applies to every part of the File::Util distribution.
SEE ALSO
The rest of the documentation: File::Util::Manual, File::Util::Manual::Examples,
File::Util::Cookbook
Other Useful Modules that do similar things: File::Slurp, File::Spec, File::Find::Rule,
Path::Class, Path::Tiny