IO::All(3) User Contributed Perl Documentation IO::All(3)NAMEIO::All - IO::All of it to Graham and Damian!
SYNOPSIS
use IO::All; # Let the madness begin...
# Some of the many ways to read a whole file into a scalar
io('file.txt') > $contents; # Overloaded "arrow"
$contents < io 'file.txt'; # Flipped but same operation
$io = io 'file.txt'; # Create a new IO::All object
$contents = $$io; # Overloaded scalar dereference
$contents = $io->all; # A method to read everything
$contents = $io->slurp; # Another method for that
$contents = join '', $io->getlines; # Join the separate lines
$contents = join '', map "$_\n", @$io; # Same. Overloaded array deref
$io->tie; # Tie the object as a handle
$contents = join '', <$io>; # And use it in builtins
# and the list goes on ...
# Other file operations:
@lines = io('file.txt')->slurp; # List context slurp
$content > io('file.txt'); # Print to a file
io('file.txt')->print($content, $more); # (ditto)
$content >> io('file.txt'); # Append to a file
io('file.txt')->append($content); # (ditto)
$content << $io; # Append to a string
io('copy.txt') < io('file.txt'); $ Copy a file
io('file.txt') > io('copy.txt'); # Invokes File::Copy
io('more.txt') >> io('all.txt'); # Add on to a file
# UTF-8 Support
$contents = io('file.txt')->utf8->all; # Turn on utf8
use IO::All -utf8; # Turn on utf8 for all io
$contents = io('file.txt')->all; # by default in this package.
# General Encoding Support
$contents = io('file.txt')->encoding('big5')->all;
use IO::All-encoding => 'big5'; # Turn on big5 for all io
$contents = io('file.txt')->all; # by default in this package.
# Print the path name of a file:
print $io->name; # The direct method
print "$io"; # Object stringifies to name
print $io; # Quotes not needed here
print $io->filename; # The file portion only
# Read all the files/directories in a directory:
$io = io('my/directory/'); # Create new directory object
@contents = $io->all; # Get all contents of dir
@contents = @$io; # Directory as an array
@contents = values %$io; # Directory as a hash
push @contents, $subdir # One at a time
while $subdir = $io->next;
# Print the name and file type for all the contents above:
print "$_ is a " . $_->type . "\n" # Each element of @contents
for @contents; # is an IO::All object!!
# Print first line of each file:
print $_->getline # getline gets one line
for io('dir')->all_files; # Files only
# Print names of all files/dirs three directories deep:
print "$_\n" for $io->all(3); # Pass in the depth. Default=1
# Print names of all files/dirs recursively:
print "$_\n" for $io->all(0); # Zero means all the way down
print "$_\n" for $io->All; # Capitalized shortcut
print "$_\n" for $io->deep->all; # Another way
# There are some special file names:
print io('-'); # Print STDIN to STDOUT
io('-') > io('-'); # Do it again
io('-') < io('-'); # Same. Context sensitive.
"Bad puppy" > io('='); # Message to STDERR
$string_file = io('$'); # Create IO::String Object
$temp_file = io('?'); # Create a temporary file
# Socket operations:
$server = io('localhost:5555')->fork; # Create a daemon socket
$connection = $server->accept; # Get a connection socket
$input < $connection; # Get some data from it
"Thank you!" > $connection; # Thank the caller
$connection->close; # Hang up
io(':6666')->accept->slurp > io->devnull; # Take a complaint and file it
# DBM database operations:
$dbm = io 'my/database'; # Create a database object
print $dbm->{grocery_list}; # Hash context makes it a DBM
$dbm->{todo} = $new_list; # Write to database
$dbm->dbm('GDBM_file'); # Demand specific DBM
io('mydb')->mldbm->{env} = \%ENV; # MLDBM support
# Tie::File support:
$io = io 'file.txt';
$io->[42] = 'Line Forty Three'; # Change a line
print $io->[@$io / 2]; # Print middle line
@$io = reverse @$io; # Reverse lines in a file
# Stat functions:
printf "%s %s %s\n", # Print name, uid and size of
$_->name, $_->uid, $_->size # contents of current directory
for io('.')->all;
print "$_\n" for sort # Use mtime method to sort all
{$b->mtime <=> $a->mtime} # files under current directory
io('.')->All_Files; # by recent modification time.
# File::Spec support:
$contents < io->catfile(qw(dir file.txt)); # Portable IO operation
# Miscellaneous:
@lines = io('file.txt')->chomp->slurp; # Chomp as you slurp
@chunks =
io('file.txt')->separator('xxx')->slurp; # Use alternnate record sep
$binary = io('file.bin')->binary->all; # Read a binary file
io('a-symlink')->readlink->slurp; # Readlink returns an object
print io('foo')->absolute->pathname; # Print absolute path of foo
# IO::All External Plugin Methods
io("myfile") > io->("ftp://store.org"); # Upload a file using ftp
$html < io->http("www.google.com"); # Grab a web page
io('mailto:worst@enemy.net')->print($spam); # Email a "friend"
# This is just the beginning, read on...
DESCRIPTION
"Graham Barr for doing it all. Damian Conway for doing it all
different."
IO::All combines all of the best Perl IO modules into a single nifty
object oriented interface to greatly simplify your everyday Perl IO
idioms. It exports a single function called "io", which returns a new
IO::All object. And that object can do it all!
The IO::All object is a proxy for IO::File, IO::Dir, IO::Socket,
IO::String, Tie::File, File::Spec, File::Path and File::ReadBackwards;
as well as all the DBM and MLDBM modules. You can use most of the
methods found in these classes and in IO::Handle (which they inherit
from). IO::All adds dozens of other helpful idiomatic methods including
file stat and manipulation functions.
IO::All is pluggable, and modules like IO::All::LWP and IO::All::Mailto
add even more functionality. Optionally, every IO::All object can be
tied to itself. This means that you can use most perl IO builtins on
it: readline, <>, getc, print, printf, syswrite, sysread, close.
The distinguishing magic of IO::All is that it will automatically open
(and close) files, directories, sockets and other IO things for you.
You never need to specify the mode ('<', '>>', etc), since it is
determined by the usage context. That means you can replace this:
open STUFF, '<', './mystuff'
or die "Can't open './mystuff' for input:\n$!";
local $/;
my $stuff = <STUFF>;
close STUFF;
with this:
my $stuff < io"./mystuff";
And that is a good thing!
USAGE
Normally just say:
use IO::All;
and IO::All will export a single function called "io", which contructs
all IO objects.
You can also pass global flags like this:
use IO::All-strict -encoding => 'big5', -foobar;
Which automatically makes those method calls on every new IO object. In
other words this:
my $io = io('lalala.txt');
becomes this:
my $io = io('lalala.txt')->strict->encoding('big5')->foobar;
METHOD ROLE CALL
Here is an alphabetical list of all the public methods that you can
call on an IO::All object.
"abs2rel", "absolute", "accept", "All", "all", "All_Dirs", "all_dirs",
"All_Files", "all_files", "All_Links", "all_links", "append",
"appendf", "appendln", "assert", "atime", "autoclose", "autoflush",
"backwards", "bcc", "binary", "binmode", "blksize", "blocks",
"block_size", "buffer", "canonpath", "case_tolerant", "catdir",
"catfile", "catpath", "cc", "chdir", "chomp", "clear", "close",
"confess", "content", "ctime", "curdir", "dbm", "deep", "device",
"device_id", "devnull", "dir", "domain", "empty", "encoding", "eof",
"errors", "file", "filename", "fileno", "filepath", "filter", "fork",
"from", "ftp", "get", "getc", "getline", "getlines", "gid", "handle",
"head", "http", "https", "inode", "io_handle", "is_absolute", "is_dir",
"is_dbm", "is_executable", "is_file", "is_link", "is_mldbm", "is_open",
"is_pipe", "is_readable", "is_socket", "is_stdio", "is_string",
"is_temp", "is_writable", "join", "length", "link", "lock", "mailer",
"mailto", "mkdir", "mkpath", "mldbm", "mode", "modes", "mtime", "name",
"new", "next", "nlink", "open", "password", "path", "pathname",
"perms", "pipe", "port", "print", "printf", "println", "put", "rdonly",
"rdwr", "read", "readdir", "readlink", "recv", "rel2abs", "relative",
"rename", "request", "response", "rmdir", "rmtree", "rootdir",
"scalar", "seek", "send", "separator", "shutdown", "size", "slurp",
"socket", "sort", "splitdir", "splitpath", "stat", "stdio", "stderr",
"stdin", "stdout", "strict", "string", "string_ref", "subject",
"sysread", "syswrite", "tail", "tell", "temp", "tie", "tmpdir", "to",
"touch", "truncate", "type", "user", "uid", "unlink", "unlock",
"updir", "uri", "utf8", "utime" and "write".
Each method is documented further below.
OPERATOR OVERLOADINGIO::All objects overload a small set of Perl operators to great effect.
The overloads are limited to <, <<, >, >>, dereferencing operations,
and stringification.
Even though relatively few operations are overloaded, there is actually
a huge matrix of possibilities for magic. That's because the
overloading is sensitive to the types, position and context of the
arguments, and an IO::All object can be one of many types.
The most important overload to grok is stringification. IO::All objects
stringify to their file or directory name. Here we print the contents
of the current directory:
perl -MIO::All -le 'print for io(".")->all'
is the same as:
perl -MIO::All -le 'print $_->name for io(".")->all'
Stringification is important because it allows IO::All operations to
return objects when they might otherwise return file names. Then the
recipient can use the result either as an object or a string.
'>' and '<' move data between objects in the direction pointed to by
the operator.
$content1 < io('file1');
$content1 > io('file2');
io('file2') > $content3;
io('file3') < $content3;
io('file3') > io('file4');
io('file5') < io('file4');
'>>' and '<<' do the same thing except the recipent string or file is
appended to.
An IO::All file used as an array reference becomes tied using
Tie::File:
$file = io"file";
# Print last line of file
print $file->[-1];
# Insert new line in middle of file
$file->[$#$file / 2] = 'New line';
An IO::All file used as a hash reference becomes tied to a DBM class:
io('mydbm')->{ingy} = 'YAML';
An IO::All directory used as an array reference, will expose each file
or subdirectory as an element of the array.
print "$_\n" for @{io 'dir'};
IO::All directories used as hash references have file names as keys,
and IO::All objects as values:
print io('dir')->{'foo.txt'}->slurp;
Files used as scalar references get slurped:
print ${io('dir')->{'foo.txt'}};
Not all combinations of operations and object types are supported. Some
just haven't been added yet, and some just don't make sense. If you use
an invalid combination, an error will be thrown.
COOKBOOK
This section describes some various things that you can easily cook up
with IO::All.
File Locking
IO::All makes it very easy to lock files. Just use the "lock" method.
Here's a standalone program that demonstrates locking for both write
and read:
use IO::All;
my $io1 = io('myfile')->lock;
$io1->println('line 1');
fork or do {
my $io2 = io('myfile')->lock;
print $io2->slurp;
exit;
};
sleep 1;
$io1->println('line 2');
$io1->println('line 3');
$io1->unlock;
There are a lot of subtle things going on here. An exclusive lock is
issued for $io1 on the first "println". That's because the file isn't
actually opened until the first IO operation.
When the child process tries to read the file using $io2, there is a
shared lock put on it. Since $io1 has the exclusive lock, the slurp
blocks.
The parent process sleeps just to make sure the child process gets a
chance. The parent needs to call "unlock" or "close" to release the
lock. If all goes well the child will print 3 lines.
Round Robin
This simple example will read lines from a file forever. When the last
line is read, it will reopen the file and read the first one again.
my $io = io'file1.txt';
$io->autoclose(1);
while (my $line = $io->getline || $io->getline) {
print $line;
}
Reading Backwards
If you call the "backwards" method on an IO::All object, the "getline"
and "getlines" will work in reverse. They will read the lines in the
file from the end to the beginning.
my @reversed;
my $io = io('file1.txt');
$io->backwards;
while (my $line = $io->getline) {
push @reversed, $line;
}
or more simply:
my @reversed = io('file1.txt')->backwards->getlines;
The "backwards" method returns the IO::All object so that you can chain
the calls.
NOTE: This operation requires that you have the File::ReadBackwards
module installed.
Client/Server Sockets
IO::All makes it really easy to write a forking socket server and a
client to talk to it.
In this example, a server will return 3 lines of text, to every client
that calls it. Here is the server code:
use IO::All;
my $socket = io(':12345')->fork->accept;
$socket->print($_) while <DATA>;
$socket->close;
__DATA__
On your mark,
Get set,
Go!
Here is the client code:
use IO::All;
my $io = io('localhost:12345');
print while $_ = $io->getline;
You can run the server once, and then run the client repeatedly (in
another terminal window). It should print the 3 data lines each time.
Note that it is important to close the socket if the server is forking,
or else the socket won't go out of scope and close.
A Tiny Web Server
Here is how you could write a simplistic web server that works with
static and dynamic pages:
perl -MIO::All -e 'io(":8080")->fork->accept->(sub { $_[0] < io(-x $1 ? "./$1 |" : $1) if /^GET \/(.*) / })'
There is are a lot of subtle things going on here. First we accept a
socket and fork the server. Then we overload the new socket as a code
ref. This code ref takes one argument, another code ref, which is used
as a callback.
The callback is called once for every line read on the socket. The line
is put into $_ and the socket itself is passed in to the callback.
Our callback is scanning the line in $_ for an HTTP GET request. If one
is found it parses the file name into $1. Then we use $1 to create an
new IO::All file object... with a twist. If the file is executable
("-x"), then we create a piped command as our IO::All object. This
somewhat approximates CGI support.
Whatever the resulting object is, we direct the contents back at our
socket which is in $_[0]. Pretty simple, eh?
DBM Files
IO::All file objects used as a hash reference, treat the file as a DBM
tied to a hash. Here I write my DB record to STDERR:
io("names.db")->{ingy} > io'=';
Since their are several DBM formats available in Perl, IO::All picks
the first one of these that is installed on your system:
DB_File GDBM_File NDBM_File ODBM_File SDBM_File
You can override which DBM you want for each IO::All object:
my @keys = keys %{io('mydbm')->dbm('SDBM_File')};
File Subclassing
Subclassing is easy with IO::All. Just create a new module and use
IO::All as the base class, like this:
package NewModule;
use IO::All -base;
You need to do it this way so that IO::All will export the "io"
function. Here is a simple recipe for subclassing:
IO::Dumper inherits everything from IO::All and adds an extra method
called "dump", which will dump a data structure to the file we specify
in the "io" function. Since it needs Data::Dumper to do the dumping, we
override the "open" method to "require Data::Dumper" and then pass
control to the real "open".
First the code using the module:
use IO::Dumper;
io('./mydump')->dump($hash);
And next the IO::Dumper module itself:
package IO::Dumper;
use IO::All -base;
use Data::Dumper;
sub dump {
my $self = shift;
Dumper(@_) > $self;
}
1;
Inline Subclassing
This recipe does the same thing as the previous one, but without
needing to write a separate module. The only real difference is the
first line. Since you don't "use" IO::Dumper, you need to still call
its "import" method manually.
IO::Dumper->import;
io('./mydump')->dump($hash);
package IO::Dumper;
use IO::All -base;
use Data::Dumper;
sub dump {
my $self = shift;
Dumper(@_) > $self;
}
THE IO::All METHODS
This section gives a full description of all of the methods that you
can call on IO::All objects. The methods have been grouped into
subsections based on object construction, option settings,
configuration, action methods and support for specific modules.
Object Construction and Initialization Methods
· new
There are three ways to create a new IO::All object. The first is
with the special function "io" which really just calls
"IO::All->new". The second is by calling "new" as a class method.
The third is calling "new" as an object instance method. In this
final case, the new objects attributes are copied from the instance
object.
io(file-descriptor);
IO::All->new(file-descriptor);
$io->new(file-descriptor);
All three forms take a single argument, a file descriptor. A file
descriptor can be any of the following:
- A file name
- A file handle
- A directory name
- A directory handle
- A typeglob reference
- A piped shell command. eq '| ls -al'
- A socket domain/port. eg 'perl.com:5678'
- '-' means STDIN or STDOUT (depending on usage)
- '=' means STDERR
- '$' means an IO::String object
- '?' means a temporary file
- A URI including: http, https, ftp and mailto
- An IO::All object
If you provide an IO::All object, you will simply get that same
object returned from the constructor.
If no file descriptor is provided, an object will still be created,
but it must be defined by one of the following methods before it
can be used for I/O:
· file
io->file(file-name);
Using the "file" method sets the type of the object to file and
sets the pathname of the file if provided.
It might be important to use this method if you had a file whose
name was '-', or if the name might otherwise be confused with a
directory or a socket. In this case, either of these statements
would work the same:
my $file = io('-')->file;
my $file = io->file('-');
· dir
io->file(dir-name);
Make the object be of type directory.
· socket
io->file(domain:port);
Make the object be of type socket.
· link
io->file(link-name);
Make the object be of type link.
· pipe
io->file(link-name);
Make the object be of type pipe. The following two statements are
equivalent:
my $io = io('ls -l |');
my $io = io('ls -l')->pipe;
my $io = io->pipe('ls -l');
· dbm
This method takes the names of zero or more DBM modules. The first
one that is available is used to process the dbm file.
io('mydbm')->dbm('NDBM_File', 'SDBM_File')->{author} = 'ingy';
If no module names are provided, the first available of the
following is used:
DB_File GDBM_File NDBM_File ODBM_File SDBM_File
· mldbm
Similar to the "dbm" method, except create a Multi Level DBM object
using the MLDBM module.
This method takes the names of zero or more DBM modules and an
optional serialization module. The first DBM module that is
available is used to process the MLDBM file. The serialization
module can be Data::Dumper, Storable or FreezeThaw.
io('mymldbm')->mldbm('GDBM_File', 'Storable')->{author} =
{nickname => 'ingy'};
· string
Make the object be a IO::String object. These are equivalent:
my $io = io('$');
my $io = io->string;
· temp
Make the object represent a temporary file. It will automatically
be open for both read and write.
· stdio
Make the object represent either STDIN or STDOUT depending on how
it is used subsequently. These are equivalent:
my $io = io('-');
my $io = io->stdin;
· stdin
Make the object represent STDIN.
· stdout
Make the object represent STDOUT.
· stderr
Make the object represent STDERR.
· handle
io->handle(io-handle);
Forces the object to be created from an pre-existing IO handle. You
can chain calls together to indicate the type of handle:
my $file_object = io->file->handle($file_handle);
my $dir_object = io->dir->handle($dir_handle);
· http
Make the object represent an http uri. Requires IO-All-LWP.
· https
Make the object represent an https uri. Requires IO-All-LWP.
· ftp
Make the object represent a ftp uri. Requires IO-All-LWP.
· mailto
Make the object represent a mailto uri. Requires IO-All-Mailto.
If you need to use the same options to create a lot of objects, and
don't want to duplicate the code, just create a dummy object with the
options you want, and use that object to spawn other objects.
my $lt = io->lock->tie;
...
my $io1 = $lt->new('file1');
my $io2 = $lt->new('file2');
Since the new method copies attributes from the calling object, both
$io1 and $io2 will be locked and tied.
Option Setting Methods
The following methods don't do any actual I/O, but they specify options
about how the I/O should be done.
Each option can take a single argument of 0 or 1. If no argument is
given, the value 1 is assumed. Passing 0 turns the option off.
All of these options return the object reference that was used to
invoke them. This is so that the option methods can be chained
together. For example:
my $io = io('path/file')->tie->assert->chomp->lock;
· absolute
Indicates that the "pathname" for the object should be made
absolute.
· assert
This method ensures that the path for a file or directory actually
exists before the file is open. If the path does not exist, it is
created.
· autoclose
By default, IO::All will close an object opened for input when EOF
is reached. By closing the handle early, one can immediately do
other operations on the object without first having to close it.
This option is on by default, so if you don't want this behaviour,
say so like this:
$io->autoclose(0);
The object will then be closed when $io goes out of scope, or you
manually call "$io->close".
· autoflush
Proxy for IO::Handle::autoflush
· backwards
Sets the object to 'backwards' mode. All subsequent "getline"
operations will read backwards from the end of the file.
Requires the File::ReadBackwards CPAN module.
· binary
Indicates the file has binary content and should be opened with
"binmode".
· chdir
chdir() to the pathname of a directory object. When object goes out
of scope, chdir back to starting directory.
· chomp
Indicates that all operations that read lines should chomp the
lines. If the "separator" method has been called, chomp will remove
that value from the end of each record.
· confess
Errors should be reported with the very detailed Carp::confess
function.
· deep
Indicates that calls to the "all" family of methods should search
directories as deep as possible.
· fork
Indicates that the process should automatically be forked inside
the "accept" socket method.
· lock
Indicate that operations on an object should be locked using flock.
· rdonly
This option indicates that certain operations like DBM and
Tie::File access should be done in read-only mode.
· rdwr
This option indicates that DBM and MLDBM files should be opened in
read- write mode.
· relative
Indicates that the "pathname" for the object should be made
relative.
· sort
Indicates whether objects returned from one of the "all" methods
will be in sorted order by name. True by default.
· strict
Check the return codes of every single system call. To turn this on
for all calls in your module, use:
use IO::All -strict;
· tie
Indicate that the object should be tied to itself, thus allowing it
to be used as a filehandle in any of Perl's builtin IO operations.
my $io = io('foo')->tie;
@lines = <$io>;
· utf8
Indicates that IO should be done using utf8 encoding. Calls binmode
with ":utf8" layer.
Configuration Methods
The following methods don't do any actual I/O, but they set specific
values to configure the IO::All object.
If these methods are passed no argument, they will return their current
value. If arguments are passed they will be used to set the current
value, and the object reference will be returned for potential method
chaining.
· bcc
Set the Bcc field for a mailto object.
· binmode
Proxy for binmode. Requires a layer to be passed. Use "binary" for
plain binary mode.
· block_size
The default length to be used for "read" and "sysread" calls.
Defaults to 1024.
· buffer
Returns a reference to the internal buffer, which is a scalar. You
can use this method to set the buffer to a scalar of your choice.
(You can just pass in the scalar, rather than a reference to it.)
This is the buffer that "read" and "write" will use by default.
You can easily have IO::All objects use the same buffer:
my $input = io('abc');
my $output = io('xyz');
my $buffer;
$output->buffer($input->buffer($buffer));
$output->write while $input->read;
· cc
Set the Cc field for a mailto object.
· content
Get or set the content for an LWP operation manually.
· domain
Set the domain name or ip address that a socket should use.
· encoding
Set the encoding to be used for the PerlIO layer.
· errors
Use this to set a subroutine reference that gets called when an
internal error is thrown.
· filter
Use this to set a subroutine reference that will be used to grep
which objects get returned on a call to one of the "all" methods.
For example:
my @odd = io->curdir->filter(sub {$_->size % 2})->All_Files;
@odd will contain all the files under the current directory whose
size is an odd number of bytes.
· from
Indicate the sender for a mailto object.
· mailer
Set the mailer program for a mailto transaction. Defaults to
'sendmail'.
· mode
Set the mode for which the file should be opened. Examples:
$io->mode('>>')->open;
$io->mode(O_RDONLY);
my $log_appender = io->file('/var/log/my-application.log')
->mode('>>')->open();
$log_appender->print("Stardate 5987.6: Mission accomplished.");
· name
Set or get the name of the file or directory represented by the
IO::All object.
· password
Set the password for an LWP transaction.
· perms
Sets the permissions to be used if the file/directory needs to be
created.
· port
Set the port number that a socket should use.
· request
Manually specify the request object for an LWP transaction.
· response
Returns the resulting reponse object from an LWP transaction.
· separator
Sets the record (line) separator to whatever value you pass it.
Default is \n. Affects the chomp setting too.
· string_ref
Proxy for IO::String::string_ref
Returns a reference to the internal string that is acting like a
file.
· subject
Set the subject for a mailto transaction.
· to
Set the recipient address for a mailto request.
· uri
Direct access to the URI used in LWP transactions.
· user
Set the user name for an LWP transaction.
IO Action Methods
These are the methods that actually perform I/O operations on an
IO::All object. The stat methods and the File::Spec methods are
documented in separate sections below.
· accept
For sockets. Opens a server socket (LISTEN => 1, REUSE => 1).
Returns an IO::All socket object that you are listening on.
If the "fork" method was called on the object, the process will
automatically be forked for every connection.
· all
Read all contents into a single string.
compare(io('file1')->all, io('file2')->all);
· all (For directories)
Returns a list of IO::All objects for all files and subdirectories
in a directory.
'.' and '..' are excluded.
Takes an optional argument telling how many directories deep to
search. The default is 1. Zero (0) means search as deep as
possible.
The filter method can be used to limit the results.
The items returned are sorted by name unless "->sort(0)" is used.
· All
Same as all(0).
· all_dirs
Same as "all", but only return directories.
· All_Dirs
Same as all_dirs(0).
· all_files
Same as "all", but only return files.
· All_Files
Same as all_files(0).
· all_links
Same as "all", but only return links.
· All_Links
Same as all_links(0).
· append
Same as print, but sets the file mode to '>>'.
· appendf
Same as printf, but sets the file mode to '>>'.
· appendln
Same as println, but sets the file mode to '>>'.
· clear
Clear the internal buffer. This method is called by "write" after
it writes the buffer. Returns the object reference for chaining.
· close
Close will basically unopen the object, which has different
meanings for different objects. For files and directories it will
close and release the handle. For sockets it calls shutdown. For
tied things it unties them, and it unlocks locked things.
· empty
Returns true if a file exists but has no size, or if a directory
exists but has no contents.
· eof
Proxy for IO::Handle::eof
· exists
Returns whether or not the file or directory exists.
· filename
Return the name portion of the file path in the object. For
example:
io('my/path/file.txt')->filename;
would return "file.txt".
· fileno
Proxy for IO::Handle::fileno
· filepath
Return the path portion of the file path in the object. For
example:
io('my/path/file.txt')->filename;
would return "my/path".
· get
Perform an LWP GET request manually.
· getc
Proxy for IO::Handle::getc
· getline
Calls IO::File::getline. You can pass in an optional record
separator.
· getlines
Calls IO::File::getlines. You can pass in an optional record
separator.
· head
Return the first 10 lines of a file. Takes an optional argument
which is the number of lines to return. Works as expected in list
and scalar context. Is subject to the current line separator.
· io_handle
Direct access to the actual IO::Handle object being used on an
opened IO::All object.
· is_dir
Returns boolean telling whether or not the IO::All object
represents a directory.
· is_executable
Returns true if file or directory is executable.
· is_dbm
Returns boolean telling whether or not the IO::All object
represents a dbm file.
· is_file
Returns boolean telling whether or not the IO::All object
represents a file.
· is_link
Returns boolean telling whether or not the IO::All object
represents a symlink.
· is_mldbm
Returns boolean telling whether or not the IO::All object
represents a mldbm file.
· is_open
Indicates whether the IO::All is currently open for input/output.
· is_pipe
Returns boolean telling whether or not the IO::All object
represents a pipe operation.
· is_readable
Returns true if file or directory is readable.
· is_socket
Returns boolean telling whether or not the IO::All object
represents a socket.
· is_stdio
Returns boolean telling whether or not the IO::All object
represents a STDIO file handle.
· is_string
Returns boolean telling whether or not the IO::All object
represents an IO::String object.
· is_temp
Returns boolean telling whether or not the IO::All object
represents a temporary file.
· is_writable
Returns true if file or directory is writable. Can also be spelled
as "is_writeable".
· length
Return the length of the internal buffer.
· mkdir
Create the directory represented by the object.
· mkpath
Create the directory represented by the object, when the path
contains more than one directory that doesn't exist. Proxy for
File::Path::mkpath.
· next
For a directory, this will return a new IO::All object for each
file or subdirectory in the directory. Return undef on EOD.
· open
Open the IO::All object. Takes two optional arguments "mode" and
"perms", which can also be set ahead of time using the "mode" and
"perms" methods.
NOTE: Normally you won't need to call open (or mode/perms), since
this happens automatically for most operations.
· pathname
Return the absolute or relative pathname for a file or directory,
depending on whether object is in "absolute" or "relative" mode.
· print
Proxy for IO::Handle::print
· printf
Proxy for IO::Handle::printf
· println
Same as print, but adds newline to each argument unless it already
ends with one.
· put
Perform an LWP PUT request manually.
· read
This method varies depending on its context. Read carefully (no pun
intended).
For a file, this will proxy IO::File::read. This means you must
pass it a buffer, a length to read, and optionally a buffer offset
for where to put the data that is read. The function returns the
length actually read (which is zero at EOF).
If you don't pass any arguments for a file, IO::All will use its
own internal buffer, a default length, and the offset will always
point at the end of the buffer. The buffer can be accessed with the
"buffer" method. The length can be set with the "block_size"
method. The default length is 1024 bytes. The "clear" method can be
called to clear the buffer.
For a directory, this will proxy IO::Dir::read.
· readdir
Similar to the Perl "readdir" builtin. In scalar context, return
the next directory entry (ie file or directory name), or undef on
end of directory. In list context, return all directory entries.
Note that "readdir" does not return the special "." and ".."
entries.
· readline
Same as "getline".
· readlink
Calls Perl's readlink function on the link represented by the
object. Instead of returning the file path, it returns a new
IO::All object using the file path.
· recv
Proxy for IO::Socket::recv
· rename
my $new = $io->rename('new-name');
Calls Perl's rename function and returns an IO::All object for the
renamed file. Returns false if the rename failed.
· rewind
Proxy for IO::Dir::rewind
· rmdir
Delete the directory represented by the IO::All object.
· rmtree
Delete the directory represented by the IO::All object and all the
files and directories beneath it. Proxy for File::Path::rmtree.
· scalar
Deprecated. Same as "all()".
· seek
Proxy for IO::Handle::seek. If you use seek on an unopened file, it
will be opened for both read and write.
· send
Proxy for IO::Socket::send
· shutdown
Proxy for IO::Socket::shutdown
· slurp
Read all file content in one operation. Returns the file content as
a string. In list context returns every line in the file.
· stat
Proxy for IO::Handle::stat
· sysread
Proxy for IO::Handle::sysread
· syswrite
Proxy for IO::Handle::syswrite
· tail
Return the last 10 lines of a file. Takes an optional argument
which is the number of lines to return. Works as expected in list
and scalar context. Is subject to the current line separator.
· tell
Proxy for IO::Handle::tell
· throw
This is an internal method that gets called whenever there is an
error. It could be useful to override it in a subclass, to provide
more control in error handling.
· touch
Update the atime and mtime values for a file or directory. Creates
an empty file if the file does not exist.
· truncate
Proxy for IO::Handle::truncate
· type
Returns a string indicated the type of io object. Possible values
are:
file
dir
link
socket
string
pipe
Returns undef if type is not determinable.
· unlink
Unlink (delete) the file represented by the IO::All object.
NOTE: You can unlink a file after it is open, and continue using it
until it is closed.
· unlock
Release a lock from an object that used the "lock" method.
· utime
Proxy for the utime Perl function.
· write
Opposite of "read" for file operations only.
NOTE: When used with the automatic internal buffer, "write" will
clear the buffer after writing it.
Stat Methods
This methods get individual values from a stat call on the file,
directory or handle represented by th IO::All object.
· atime
Last access time in seconds since the epoch
· blksize
Preferred block size for file system I/O
· blocks
Actual number of blocks allocated
· ctime
Inode change time in seconds since the epoch
· device
Device number of filesystem
· device_id
Device identifier for special files only
· gid
Numeric group id of file's owner
· inode
Inode number
· modes
File mode - type and permissions
· mtime
Last modify time in seconds since the epoch
· nlink
Number of hard links to the file
· size
Total size of file in bytes
· uid
Numeric user id of file's owner
File::Spec Methods
These methods are all adaptations from File::Spec. Each method actually
does call the matching File::Spec method, but the arguments and return
values differ slightly. Instead of being file and directory names, they
are IO::All objects. Since IO::All objects stringify to their names,
you can generally use the methods just like File::Spec.
· abs2rel
Returns the relative path for the absolute path in the IO::All
object. Can take an optional argument indicating the base path.
· canonpath
Returns the canonical path for the IO::All object.
· case_tolerant
Returns 0 or 1 indicating whether the file system is case tolerant.
Since an active IO::All object is not needed for this function, you
can code it like:
IO::All->case_tolerant;
or more simply:
io->case_tolerant;
· catdir
Concatenate the directory components together, and return a new
IO::All object representing the resulting directory.
· catfile
Concatenate the directory and file components together, and return
a new IO::All object representing the resulting file.
my $contents = io->catfile(qw(dir subdir file))->slurp;
This is a very portable way to read "dir/subdir/file".
· catpath
Concatenate the volume, directory and file components together, and
return a new IO::All object representing the resulting file.
· curdir
Returns an IO::All object representing the current directory.
· devnull
Returns an IO::All object representing the /dev/null file.
· is_absolute
Returns 0 or 1 indicating whether the "name" field of the IO::All
object is an absolute path.
· join
Same as "catfile".
· path
Returns a list of IO::All directory objects for each directory in
your path.
· rel2abs
Returns the absolute path for the relative path in the IO::All
object. Can take an optional argument indicating the base path.
· rootdir
Returns an IO::All object representing the root directory on your
file system.
· splitdir
Returns a list of the directory components of a path in an IO::All
object.
· splitpath
Returns a volume directory and file component of a path in an
IO::All object.
· tmpdir
Returns an IO::All object representing a temporary directory on
your file system.
· updir
Returns an IO::All object representing the current parent
directory.
OPERATIONAL NOTES
· Each IO::All object gets reblessed into an IO::All::* object as
soon as IO::All can determine what type of object it should be.
Sometimes it gets reblessed more than once:
my $io = io('mydbm.db');
$io->dbm('DB_File');
$io->{foo} = 'bar';
In the first statement, $io has a reference value of
'IO::All::File', if "mydbm.db" exists. In the second statement, the
object is reblessed into class 'IO::All::DBM'.
· An IO::All object will automatically be opened as soon as there is
enough contextual information to know what type of object it is,
and what mode it should be opened for. This is usually when the
first read or write operation is invoked but might be sooner.
· The mode for an object to be opened with is determined
heuristically unless specified explicitly.
· For input, IO::All objects will automatically be closed after EOF
(or EOD). For output, the object closes when it goes out of scope.
To keep input objects from closing at EOF, do this:
$io->autoclose(0);
· You can always call "open" and "close" explicitly, if you need that
level of control. To test if an object is currently open, use the
"is_open" method.
· Overloaded operations return the target object, if one exists.
This would set $xxx to the IO::All object:
my $xxx = $contents > io('file.txt');
While this would set $xxx to the content string:
my $xxx = $contents < io('file.txt');
STABILITY
The goal of the IO::All project is to continually refine the module to
be as simple and consistent to use as possible. Therefore, in the early
stages of the project, I will not hesitate to break backwards
compatibility with other versions of IO::All if I can find an easier
and clearer way to do a particular thing.
IO is tricky stuff. There is definitely more work to be done. On the
other hand, this module relies heavily on very stable existing IO
modules; so it may work fairly well.
I am sure you will find many unexpected "features". Please send all
problems, ideas and suggestions to ingy@cpan.org.
Known Bugs and Deficiencies
Not all possible combinations of objects and methods have been tested.
There are many many combinations. All of the examples have been tested.
If you find a bug with a particular combination of calls, let me know.
If you call a method that does not make sense for a particular object,
the result probably won't make sense. Little attempt is made to check
for improper usage.
SEE ALSO
IO::Handle, IO::File, IO::Dir, IO::Socket, IO::String, File::Spec,
File::Path, File::ReadBackwards, Tie::File
CREDITS
A lot of people have sent in suggestions, that have become a part of
IO::All. Thank you.
Special thanks to Ian Langworth for continued testing and patching.
Thank you Simon Cozens for tipping me off to the overloading
possibilities.
Finally, thanks to Autrijus Tang, for always having one more good idea.
(It seems IO::All of it to a lot of people!)
REPOSITORY AND COMMUNITY
The IO::All module can be found on CPAN and on GitHub:
http://github.com/ingydotnet/io-all-pm
<http://github.com/ingydotnet/io-all-pm>.
Please join the IO::All discussion on #io-all on irc.perl.org.
AUTHOR
Ingy doet Net <ingy@cpan.org>
COPYRIGHT
Copyright (c) 2004. Brian Ingerson.
Copyright (c) 2006, 2008, 2010. Ingy doet Net.
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
See <http://www.perl.com/perl/misc/Artistic.html>
perl v5.14.0 2010-08-17 IO::All(3)
