1IO::All(3) User Contributed Perl Documentation IO::All(3)
2
6 IO::All - IO::All of it to Graham and Damian!
7
9 use IO::All; # Let the madness begin...
10 # Some of the many ways to read a whole file into a scalar
12 io('file.txt') > $contents; # Overloaded "arrow"
13 $contents < io 'file.txt'; # Flipped but same operation
14 $io = io 'file.txt'; # Create a new IO::All object
15 $contents = $$io; # Overloaded scalar dereference
16 $contents = $io->all; # A method to read everything
17 $contents = $io->slurp; # Another method for that
18 $contents = join '', $io->getlines; # Join the separate lines
19 $contents = join '', map "$_\n", @$io; # Same. Overloaded array deref
20 $io->tie; # Tie the object as a handle
21 $contents = join '', <$io>; # And use it in builtins
22 # and the list goes on ...
23 # Other file operations:
25 @lines = io('file.txt')->slurp; # List context slurp
26 $content > io('file.txt'); # Print to a file
27 io('file.txt')->print($content, $more); # (ditto)
28 $content >> io('file.txt'); # Append to a file
29 io('file.txt')->append($content); # (ditto)
30 $content << $io; # Append to a string
31 io('copy.txt') < io('file.txt'); $ Copy a file
32 io('file.txt') > io('copy.txt'); # Invokes File::Copy
33 io('more.txt') >> io('all.txt'); # Add on to a file
34 # UTF-8 Support
36 $contents = io('file.txt')->utf8->all; # Turn on utf8
37 use IO::All -utf8; # Turn on utf8 for all io
38 $contents = io('file.txt')->all; # by default in this package.
39 # General Encoding Support
41 $contents = io('file.txt')->encoding('big5')->all;
42 use IO::All -encoding => 'big5'; # Turn on big5 for all io
43 $contents = io('file.txt')->all; # by default in this package.
44 # Print the path name of a file:
46 print $io->name; # The direct method
47 print "$io"; # Object stringifies to name
48 print $io; # Quotes not needed here
49 print $io->filename; # The file portion only
50 # Read all the files/directories in a directory:
52 $io = io('my/directory/'); # Create new directory object
53 @contents = $io->all; # Get all contents of dir
54 @contents = @$io; # Directory as an array
55 @contents = values %$io; # Directory as a hash
56 push @contents, $subdir # One at a time
57 while $subdir = $io->next;
58 # Print the name and file type for all the contents above:
60 print "$_ is a " . $_->type . "\n" # Each element of @contents
61 for @contents; # is an IO::All object!!
62 # Print first line of each file:
64 print $_->getline # getline gets one line
65 for io('dir')->all_files; # Files only
66 # Print names of all files/dirs three directories deep:
68 print "$_\n" for $io->all(3); # Pass in the depth. Default=1
69 # Print names of all files/dirs recursively:
71 print "$_\n" for $io->all(0); # Zero means all the way down
72 print "$_\n" for $io->All; # Capitalized shortcut
73 print "$_\n" for $io->deep->all; # Another way
74 # There are some special file names:
76 print io('-'); # Print STDIN to STDOUT
77 io('-') > io('-'); # Do it again
78 io('-') < io('-'); # Same. Context sensitive.
79 "Bad puppy" > io('='); # Message to STDERR
80 $string_file = io('$'); # Create IO::String Object
81 $temp_file = io('?'); # Create a temporary file
82 # Socket operations:
84 $server = io('localhost:5555')->fork; # Create a daemon socket
85 $connection = $server->accept; # Get a connection socket
86 $input < $connection; # Get some data from it
87 "Thank you!" > $connection; # Thank the caller
88 $connection->close; # Hang up
89 io(':6666')->accept->slurp > io->devnull; # Take a complaint and file it
90 # DBM database operations:
92 $dbm = io 'my/database'; # Create a database object
93 print $dbm->{grocery_list}; # Hash context makes it a DBM
94 $dbm->{todo} = $new_list; # Write to database
95 $dbm->dbm('GDBM_file'); # Demand specific DBM
96 io('mydb')->mldbm->{env} = \%ENV; # MLDBM support
97 # Tie::File support:
99 $io = io 'file.txt';
100 $io->[42] = 'Line Forty Three'; # Change a line
101 print $io->[@$io / 2]; # Print middle line
102 @$io = reverse @$io; # Reverse lines in a file
103 # Stat functions:
105 printf "%s %s %s\n", # Print name, uid and size of
106 $_->name, $_->uid, $_->size # contents of current directory
107 for io('.')->all;
108 print "$_\n" for sort # Use mtime method to sort all
109 {$b->mtime <=> $a->mtime} # files under current directory
110 io('.')->All_Files; # by recent modification time.
111 # File::Spec support:
113 $contents < io->catfile(qw(dir file.txt)); # Portable IO operation
114 # Miscellaneous:
116 @lines = io('file.txt')->chomp->slurp; # Chomp as you slurp
117 @chunks =
118 io('file.txt')->separator('xxx')->slurp; # Use alternnate record sep
119 $binary = io('file.bin')->binary->all; # Read a binary file
120 io('a-symlink')->readlink->slurp; # Readlink returns an object
121 print io('foo')->absolute->pathname; # Print absolute path of foo
122 # IO::All External Plugin Methods
124 io("myfile") > io->("ftp://store.org"); # Upload a file using ftp
125 $html < io->http("www.google.com"); # Grab a web page
126 io('mailto:worst@enemy.net')->print($spam); # Email a "friend"
127 # This is just the beginning, read on...
129
131 "Graham Barr for doing it all. Damian Conway for doing it all differ‐
132 ent."
133 IO::All combines all of the best Perl IO modules into a single nifty
135 object oriented interface to greatly simplify your everyday Perl IO
136 idioms. It exports a single function called "io", which returns a new
137 IO::All object. And that object can do it all!
138 The IO::All object is a proxy for IO::File, IO::Dir, IO::Socket,
140 IO::String, Tie::File, File::Spec, File::Path and File::ReadBackwards;
141 as well as all the DBM and MLDBM modules. You can use most of the meth‐
142 ods found in these classes and in IO::Handle (which they inherit from).
143 IO::All adds dozens of other helpful idiomatic methods including file
144 stat and manipulation functions.
145 IO::All is pluggable, and modules like IO::All::LWP and IO::All::Mailto
147 add even more functionality. Optionally, every IO::All object can be
148 tied to itself. This means that you can use most perl IO builtins on
149 it: readline, <>, getc, print, printf, syswrite, sysread, close.
150 The distinguishing magic of IO::All is that it will automatically open
152 (and close) files, directories, sockets and other IO things for you.
153 You never need to specify the mode ('<', '>>', etc), since it is deter‐
154 mined by the usage context. That means you can replace this:
155 open STUFF, '<', './mystuff'
157 or die "Can't open './mystuff' for input:\n$!";
158 local $/;
159 my $stuff = <STUFF>;
160 close STUFF;
161 with this:
163 my $stuff < io"./mystuff";
165 And that is a good thing!
167
169 Normally just say:
170 use IO::All;
172 and IO::All will export a single function called "io", which contructs
174 all IO objects.
175 You can also pass global flags like this:
177 use IO::All -strict -encoding => 'big5', -foobar;
179 Which automatically makes those method calls on every new IO object. In
181 other words this:
182 my $io = io('lalala.txt');
184 becomes this:
186 my $io = io('lalala.txt')->strict->encoding('big5')->foobar;
188
190 Here is an alphabetical list of all the public methods that you can
191 call on an IO::All object.
192 "abs2rel", "absolute", "accept", "All", "all", "All_Dirs", "all_dirs",
194 "All_Files", "all_files", "All_Links", "all_links", "append",
195 "appendf", "appendln", "assert", "atime", "autoclose", "autoflush",
196 "backwards", "bcc", "binary", "binmode", "blksize", "blocks",
197 "block_size", "buffer", "canonpath", "case_tolerant", "catdir", "cat‐
198 file", "catpath", "cc", "chdir", "chomp", "clear", "close", "confess",
199 "content", "ctime", "curdir", "dbm", "deep", "device", "device_id",
200 "devnull", "dir", "domain", "empty", "encoding", "eof", "errors",
201 "file", "filename", "fileno", "filepath", "filter", "fork", "from",
202 "ftp", "get", "getc", "getline", "getlines", "gid", "handle", "head",
203 "http", "https", "inode", "io_handle", "is_absolute", "is_dir",
204 "is_dbm", "is_executable", "is_file", "is_link", "is_mldbm", "is_open",
205 "is_pipe", "is_readable", "is_socket", "is_stdio", "is_string",
206 "is_temp", "is_writable", "join", "length", "link", "lock", "mailer",
207 "mailto", "mkdir", "mkpath", "mldbm", "mode", "modes", "mtime", "name",
208 "new", "next", "nlink", "open", "password", "path", "pathname",
209 "perms", "pipe", "port", "print", "printf", "println", "put", "rdonly",
210 "rdwr", "read", "readdir", "readlink", "recv", "rel2abs", "relative",
211 "rename", "request", "response", "rmdir", "rmtree", "rootdir",
212 "scalar", "seek", "send", "separator", "shutdown", "size", "slurp",
213 "socket", "sort", "splitdir", "splitpath", "stat", "stdio", "stderr",
214 "stdin", "stdout", "strict", "string", "string_ref", "subject", "sys‐
215 read", "syswrite", "tail", "tell", "temp", "tie", "tmpdir", "to",
216 "touch", "truncate", "type", "user", "uid", "unlink", "unlock",
217 "updir", "uri", "utf8", "utime" and "write".
218 Each method is documented further below.
220
222 IO::All objects overload a small set of Perl operators to great effect.
223 The overloads are limited to <, <<, >, >>, dereferencing operations,
224 and stringification.
225 Even though relatively few operations are overloaded, there is actually
227 a huge matrix of possibilities for magic. That's because the overload‐
228 ing is sensitive to the types, position and context of the arguments,
229 and an IO::All object can be one of many types.
230 The most important overload to grok is stringification. IO::All objects
232 stringify to their file or directory name. Here we print the contents
233 of the current directory:
234 perl -MIO::All -le 'print for io(".")->all'
236 is the same as:
238 perl -MIO::All -le 'print $_->name for io(".")->all'
240 Stringification is important because it allows IO::All operations to
242 return objects when they might otherwise return file names. Then the
243 recipient can use the result either as an object or a string.
244 '>' and '<' move data between objects in the direction pointed to by
246 the operator.
247 $content1 < io('file1');
249 $content1 > io('file2');
250 io('file2') > $content3;
251 io('file3') < $content3;
252 io('file3') > io('file4');
253 io('file5') < io('file4');
254 '>>' and '<<' do the same thing except the recipent string or file is
256 appended to.
257 An IO::All file used as an array reference becomes tied using
259 Tie::File:
260 $file = io"file";
262 # Print last line of file
263 print $file->[-1];
264 # Insert new line in middle of file
265 $file->[$#$file / 2] = 'New line';
266 An IO::All file used as a hash reference becomes tied to a DBM class:
268 io('mydbm')->{ingy} = 'YAML';
270 An IO::All directory used as an array reference, will expose each file
272 or subdirectory as an element of the array.
273 print "$_\n" for @{io 'dir'};
275 IO::All directories used as hash references have file names as keys,
277 and IO::All objects as values:
278 print io('dir')->{'foo.txt'}->slurp;
280 Files used as scalar references get slurped:
282 print ${io('dir')->{'foo.txt'}};
284 Not all combinations of operations and object types are supported. Some
286 just haven't been added yet, and some just don't make sense. If you use
287 an invalid combination, an error will be thrown.
288
290 This section describes some various things that you can easily cook up
291 with IO::All.
292 File Locking
294 IO::All makes it very easy to lock files. Just use the "lock" method.
296 Here's a standalone program that demonstrates locking for both write
297 and read:
298 use IO::All;
300 my $io1 = io('myfile')->lock;
301 $io1->println('line 1');
302 fork or do {
304 my $io2 = io('myfile')->lock;
305 print $io2->slurp;
306 exit;
307 };
308 sleep 1;
310 $io1->println('line 2');
311 $io1->println('line 3');
312 $io1->unlock;
313 There are a lot of subtle things going on here. An exclusive lock is
315 issued for $io1 on the first "println". That's because the file isn't
316 actually opened until the first IO operation.
317 When the child process tries to read the file using $io2, there is a
319 shared lock put on it. Since $io1 has the exclusive lock, the slurp
320 blocks.
321 The parent process sleeps just to make sure the child process gets a
323 chance. The parent needs to call "unlock" or "close" to release the
324 lock. If all goes well the child will print 3 lines.
325 Round Robin
327 This simple example will read lines from a file forever. When the last
329 line is read, it will reopen the file and read the first one again.
330 my $io = io'file1.txt';
332 $io->autoclose(1);
333 while (my $line = $io->getline ⎪⎪ $io->getline) {
334 print $line;
335 }
336 Reading Backwards
338 If you call the "backwards" method on an IO::All object, the "getline"
340 and "getlines" will work in reverse. They will read the lines in the
341 file from the end to the beginning.
342 my @reversed;
344 my $io = io('file1.txt');
345 $io->backwards;
346 while (my $line = $io->getline) {
347 push @reversed, $line;
348 }
349 or more simply:
351 my @reversed = io('file1.txt')->backwards->getlines;
353 The "backwards" method returns the IO::All object so that you can chain
355 the calls.
356 NOTE: This operation requires that you have the File::ReadBackwards
358 module installed.
359 Client/Server Sockets
361 IO::All makes it really easy to write a forking socket server and a
363 client to talk to it.
364 In this example, a server will return 3 lines of text, to every client
366 that calls it. Here is the server code:
367 use IO::All;
369 my $socket = io(':12345')->fork->accept;
371 $socket->print($_) while <DATA>;
372 $socket->close;
373 __DATA__
375 On your mark,
376 Get set,
377 Go!
378 Here is the client code:
380 use IO::All;
382 my $io = io('localhost:12345');
384 print while $_ = $io->getline;
385 You can run the server once, and then run the client repeatedly (in
387 another terminal window). It should print the 3 data lines each time.
388 Note that it is important to close the socket if the server is forking,
390 or else the socket won't go out of scope and close.
391 A Tiny Web Server
393 Here is how you could write a simplistic web server that works with
395 static and dynamic pages:
396 perl -MIO::All -e 'io(":8080")->fork->accept->(sub { $_[0] < io(-x $1 ? "./$1 ⎪" : $1) if /^GET \/(.*) / })'
398 There is are a lot of subtle things going on here. First we accept a
400 socket and fork the server. Then we overload the new socket as a code
401 ref. This code ref takes one argument, another code ref, which is used
402 as a callback.
403 The callback is called once for every line read on the socket. The line
405 is put into $_ and the socket itself is passed in to the callback.
406 Our callback is scanning the line in $_ for an HTTP GET request. If one
408 is found it parses the file name into $1. Then we use $1 to create an
409 new IO::All file object... with a twist. If the file is executable
410 ("-x"), then we create a piped command as our IO::All object. This
411 somewhat approximates CGI support.
412 Whatever the resulting object is, we direct the contents back at our
414 socket which is in $_[0]. Pretty simple, eh?
415 DBM Files
417 IO::All file objects used as a hash reference, treat the file as a DBM
419 tied to a hash. Here I write my DB record to STDERR:
420 io("names.db")->{ingy} > io'=';
422 Since their are several DBM formats available in Perl, IO::All picks
424 the first one of these that is installed on your system:
425 DB_File GDBM_File NDBM_File ODBM_File SDBM_File
427 You can override which DBM you want for each IO::All object:
429 my @keys = keys %{io('mydbm')->dbm('SDBM_File')};
431 File Subclassing
433 Subclassing is easy with IO::All. Just create a new module and use
435 IO::All as the base class, like this:
436 package NewModule;
438 use IO::All -base;
439 You need to do it this way so that IO::All will export the "io" func‐
441 tion. Here is a simple recipe for subclassing:
442 IO::Dumper inherits everything from IO::All and adds an extra method
444 called "dump", which will dump a data structure to the file we specify
445 in the "io" function. Since it needs Data::Dumper to do the dumping, we
446 override the "open" method to "require Data::Dumper" and then pass con‐
447 trol to the real "open".
448 First the code using the module:
450 use IO::Dumper;
452 io('./mydump')->dump($hash);
454 And next the IO::Dumper module itself:
456 package IO::Dumper;
458 use IO::All -base;
459 use Data::Dumper;
460 sub dump {
462 my $self = shift;
463 Dumper(@_) > $self;
464 }
465 1;
467 Inline Subclassing
469 This recipe does the same thing as the previous one, but without need‐
471 ing to write a separate module. The only real difference is the first
472 line. Since you don't "use" IO::Dumper, you need to still call its
473 "import" method manually.
474 IO::Dumper->import;
476 io('./mydump')->dump($hash);
477 package IO::Dumper;
479 use IO::All -base;
480 use Data::Dumper;
481 sub dump {
483 my $self = shift;
484 Dumper(@_) > $self;
485 }
486
488 This section gives a full description of all of the methods that you
489 can call on IO::All objects. The methods have been grouped into subsec‐
490 tions based on object construction, option settings, configuration,
491 action methods and support for specific modules.
492 Object Construction and Initialization Methods
494 * new
496 There are three ways to create a new IO::All object. The first is
497 with the special function "io" which really just calls
498 "IO::All->new". The second is by calling "new" as a class method.
499 The third is calling "new" as an object instance method. In this
500 final case, the new objects attributes are copied from the instance
501 object.
502 io(file-descriptor);
504 IO::All->new(file-descriptor);
505 $io->new(file-descriptor);
506 All three forms take a single argument, a file descriptor. A file
508 descriptor can be any of the following:
509 - A file name
511 - A file handle
512 - A directory name
513 - A directory handle
514 - A typeglob reference
515 - A piped shell command. eq '⎪ ls -al'
516 - A socket domain/port. eg 'perl.com:5678'
517 - '-' means STDIN or STDOUT (depending on usage)
518 - '=' means STDERR
519 - '$' means an IO::String object
520 - '?' means a temporary file
521 - A URI including: http, https, ftp and mailto
522 - An IO::All object
523 If you provide an IO::All object, you will simply get that same
525 object returned from the constructor.
526 If no file descriptor is provided, an object will still be created,
528 but it must be defined by one of the following methods before it
529 can be used for I/O:
530 * file
532 io->file(file-name);
533 Using the "file" method sets the type of the object to file and
535 sets the pathname of the file if provided.
536 It might be important to use this method if you had a file whose
538 name was '-', or if the name might otherwise be confused with a
539 directory or a socket. In this case, either of these statements
540 would work the same:
541 my $file = io('-')->file;
543 my $file = io->file('-');
544 * dir
546 io->file(dir-name);
547 Make the object be of type directory.
549 * socket
551 io->file(domain:port);
552 Make the object be of type socket.
554 * link
556 io->file(link-name);
557 Make the object be of type link.
559 * pipe
561 io->file(link-name);
562 Make the object be of type pipe. The following two statements are
564 equivalent:
565 my $io = io('ls -l ⎪');
567 my $io = io('ls -l')->pipe;
568 my $io = io->pipe('ls -l');
569 * dbm
571 This method takes the names of zero or more DBM modules. The first
572 one that is available is used to process the dbm file.
573 io('mydbm')->dbm('NDBM_File', 'SDBM_File')->{author} = 'ingy';
575 If no module names are provided, the first available of the follow‐
577 ing is used:
578 DB_File GDBM_File NDBM_File ODBM_File SDBM_File
580 * mldbm
582 Similar to the "dbm" method, except create a Multi Level DBM object
583 using the MLDBM module.
584 This method takes the names of zero or more DBM modules and an
586 optional serialization module. The first DBM module that is avail‐
587 able is used to process the MLDBM file. The serialization module
588 can be Data::Dumper, Storable or FreezeThaw.
589 io('mymldbm')->mldbm('GDBM_File', 'Storable')->{author} =
591 {nickname => 'ingy'};
592 * string
594 Make the object be a IO::String object. These are equivalent:
595 my $io = io('$');
597 my $io = io->string;
598 * temp
600 Make the object represent a temporary file. It will automatically
601 be open for both read and write.
602 * stdio
604 Make the object represent either STDIN or STDOUT depending on how
605 it is used subsequently. These are equivalent:
606 my $io = io('-');
608 my $io = io->stdin;
609 * stdin
611 Make the object represent STDIN.
612 * stdout
614 Make the object represent STDOUT.
615 * stderr
617 Make the object represent STDERR.
618 * handle
620 io->handle(io-handle);
621 Forces the object to be created from an pre-existing IO handle. You
623 can chain calls together to indicate the type of handle:
624 my $file_object = io->file->handle($file_handle);
626 my $dir_object = io->dir->handle($dir_handle);
627 * http
629 Make the object represent an http uri. Requires IO-All-LWP.
630 * https
632 Make the object represent an https uri. Requires IO-All-LWP.
633 * ftp
635 Make the object represent a ftp uri. Requires IO-All-LWP.
636 * mailto
638 Make the object represent a mailto uri. Requires IO-All-Mailto.
639 If you need to use the same options to create a lot of objects, and
641 don't want to duplicate the code, just create a dummy object with the
642 options you want, and use that object to spawn other objects.
643 my $lt = io->lock->tie;
645 ...
646 my $io1 = $lt->new('file1');
647 my $io2 = $lt->new('file2');
648 Since the new method copies attributes from the calling object, both
650 $io1 and $io2 will be locked and tied.
651 Option Setting Methods
653 The following methods don't do any actual I/O, but they specify options
655 about how the I/O should be done.
656 Each option can take a single argument of 0 or 1. If no argument is
658 given, the value 1 is assumed. Passing 0 turns the option off.
659 All of these options return the object reference that was used to
661 invoke them. This is so that the option methods can be chained
662 together. For example:
663 my $io = io('path/file')->tie->assert->chomp->lock;
665 * absolute
667 Indicates that the "pathname" for the object should be made abso‐
668 lute.
669 * assert
671 This method ensures that the path for a file or directory actually
672 exists before the file is open. If the path does not exist, it is
673 created.
674 * autoclose
676 By default, IO::All will close an object opened for input when EOF
677 is reached. By closing the handle early, one can immediately do
678 other operations on the object without first having to close it.
679 This option is on by default, so if you don't want this behaviour,
681 say so like this:
682 $io->autoclose(0);
684 The object will then be closed when $io goes out of scope, or you
686 manually call "$io->close".
687 * autoflush
689 Proxy for IO::Handle::autoflush
690 * backwards
692 Sets the object to 'backwards' mode. All subsequent "getline" oper‐
693 ations will read backwards from the end of the file.
694 Requires the File::ReadBackwards CPAN module.
696 * binary
698 Indicates the file has binary content and should be opened with
699 "binmode".
700 * chdir
702 chdir() to the pathname of a directory object. When object goes out
703 of scope, chdir back to starting directory.
704 * chomp
706 Indicates that all operations that read lines should chomp the
707 lines. If the "separator" method has been called, chomp will remove
708 that value from the end of each record.
709 * confess
711 Errors should be reported with the very detailed Carp::confess
712 function.
713 * deep
715 Indicates that calls to the "all" family of methods should search
716 directories as deep as possible.
717 * fork
719 Indicates that the process should automatically be forked inside
720 the "accept" socket method.
721 * lock
723 Indicate that operations on an object should be locked using flock.
724 * rdonly
726 This option indicates that certain operations like DBM and
727 Tie::File access should be done in read-only mode.
728 * rdwr
730 This option indicates that DBM and MLDBM files should be opened in
731 read- write mode.
732 * relative
734 Indicates that the "pathname" for the object should be made rela‐
735 tive.
736 * sort
738 Indicates whether objects returned from one of the "all" methods
739 will be in sorted order by name. True by default.
740 * strict
742 Check the return codes of every single system call. To turn this on
743 for all calls in your module, use:
744 use IO::All -strict;
746 * tie
748 Indicate that the object should be tied to itself, thus allowing it
749 to be used as a filehandle in any of Perl's builtin IO operations.
750 my $io = io('foo')->tie;
752 @lines = <$io>;
753 * utf8
755 Indicates that IO should be done using utf8 encoding. Calls binmode
756 with ":utf8" layer.
757 Configuration Methods
759 The following methods don't do any actual I/O, but they set specific
761 values to configure the IO::All object.
762 If these methods are passed no argument, they will return their current
764 value. If arguments are passed they will be used to set the current
765 value, and the object reference will be returned for potential method
766 chaining.
767 * bcc
769 Set the Bcc field for a mailto object.
770 * binmode
772 Proxy for binmode. Requires a layer to be passed. Use "binary" for
773 plain binary mode.
774 * block_size
776 The default length to be used for "read" and "sysread" calls.
777 Defaults to 1024.
778 * buffer
780 Returns a reference to the internal buffer, which is a scalar. You
781 can use this method to set the buffer to a scalar of your choice.
782 (You can just pass in the scalar, rather than a reference to it.)
783 This is the buffer that "read" and "write" will use by default.
785 You can easily have IO::All objects use the same buffer:
787 my $input = io('abc');
789 my $output = io('xyz');
790 my $buffer;
791 $output->buffer($input->buffer($buffer));
792 $output->write while $input->read;
793 * cc
795 Set the Cc field for a mailto object.
796 * content
798 Get or set the content for an LWP operation manually.
799 * domain
801 Set the domain name or ip address that a socket should use.
802 * encoding
804 Set the encoding to be used for the PerlIO layer.
805 * errors
807 Use this to set a subroutine reference that gets called when an
808 internal error is thrown.
809 * filter
811 Use this to set a subroutine reference that will be used to grep
812 which objects get returned on a call to one of the "all" methods.
813 For example:
814 my @odd = io->curdir->filter(sub {$_->size % 2})->All_Files;
816 @odd will contain all the files under the current directory whose
818 size is an odd number of bytes.
819 * from
821 Indicate the sender for a mailto object.
822 * mailer
824 Set the mailer program for a mailto transaction. Defaults to 'send‐
825 mail'.
826 * mode
828 Set the mode for which the file should be opened. Examples:
829 $io->mode('>>')->open;
831 $io->mode(O_RDONLY);
832 * name
834 Set or get the name of the file or directory represented by the
835 IO::All object.
836 * password
838 Set the password for an LWP transaction.
839 * perms
841 Sets the permissions to be used if the file/directory needs to be
842 created.
843 * port
845 Set the port number that a socket should use.
846 * request
848 Manually specify the request object for an LWP transaction.
849 * response
851 Returns the resulting reponse object from an LWP transaction.
852 * separator
854 Sets the record (line) separator to whatever value you pass it.
855 Default is \n. Affects the chomp setting too.
856 * string_ref
858 Proxy for IO::String::string_ref
859 Returns a reference to the internal string that is acting like a
861 file.
862 * subject
864 Set the subject for a mailto transaction.
865 * to
867 Set the recipient address for a mailto request.
868 * uri
870 Direct access to the URI used in LWP transactions.
871 * user
873 Set the user name for an LWP transaction.
874 IO Action Methods
876 These are the methods that actually perform I/O operations on an
878 IO::All object. The stat methods and the File::Spec methods are docu‐
879 mented in separate sections below.
880 * accept
882 For sockets. Opens a server socket (LISTEN => 1, REUSE => 1).
883 Returns an IO::All socket object that you are listening on.
884 If the "fork" method was called on the object, the process will
886 automatically be forked for every connection.
887 * all
889 Read all contents into a single string.
890 compare(io('file1')->all, io('file2')->all);
892 * all (For directories)
894 Returns a list of IO::All objects for all files and subdirectories
895 in a directory.
896 '.' and '..' are excluded.
898 Takes an optional argument telling how many directories deep to
900 search. The default is 1. Zero (0) means search as deep as possi‐
901 ble.
902 The filter method can be used to limit the results.
904 The items returned are sorted by name unless "->sort(0)" is used.
906 * All
908 Same as all(0).
909 * all_dirs
911 Same as "all", but only return directories.
912 * All_Dirs
914 Same as all_dirs(0).
915 * all_files
917 Same as "all", but only return files.
918 * All_Files
920 Same as all_files(0).
921 * all_links
923 Same as "all", but only return links.
924 * All_Links
926 Same as all_links(0).
927 * append
929 Same as print, but sets the file mode to '>>'.
930 * appendf
932 Same as printf, but sets the file mode to '>>'.
933 * appendln
935 Same as println, but sets the file mode to '>>'.
936 * clear
938 Clear the internal buffer. This method is called by "write" after
939 it writes the buffer. Returns the object reference for chaining.
940 * close
942 Close will basically unopen the object, which has different mean‐
943 ings for different objects. For files and directories it will close
944 and release the handle. For sockets it calls shutdown. For tied
945 things it unties them, and it unlocks locked things.
946 * empty
948 Returns true if a file exists but has no size, or if a directory
949 exists but has no contents.
950 * eof
952 Proxy for IO::Handle::eof
953 * exists
955 Returns whether or not the file or directory exists.
956 * filename
958 Return the name portion of the file path in the object. For exam‐
959 ple:
960 io('my/path/file.txt')->filename;
962 would return "file.txt".
964 * fileno
966 Proxy for IO::Handle::fileno
967 * filepath
969 Return the path portion of the file path in the object. For exam‐
970 ple:
971 io('my/path/file.txt')->filename;
973 would return "my/path".
975 * get
977 Perform an LWP GET request manually.
978 * getc
980 Proxy for IO::Handle::getc
981 * getline
983 Calls IO::File::getline. You can pass in an optional record separa‐
984 tor.
985 * getlines
987 Calls IO::File::getlines. You can pass in an optional record sepa‐
988 rator.
989 * head
991 Return the first 10 lines of a file. Takes an optional argument
992 which is the number of lines to return. Works as expected in list
993 and scalar context. Is subject to the current line separator.
994 * io_handle
996 Direct access to the actual IO::Handle object being used on an
997 opened IO::All object.
998 * is_dir
1000 Returns boolean telling whether or not the IO::All object repre‐
1001 sents a directory.
1002 * is_executable
1004 Returns true if file or directory is executable.
1005 * is_dbm
1007 Returns boolean telling whether or not the IO::All object repre‐
1008 sents a dbm file.
1009 * is_file
1011 Returns boolean telling whether or not the IO::All object repre‐
1012 sents a file.
1013 * is_link
1015 Returns boolean telling whether or not the IO::All object repre‐
1016 sents a symlink.
1017 * is_mldbm
1019 Returns boolean telling whether or not the IO::All object repre‐
1020 sents a mldbm file.
1021 * is_open
1023 Indicates whether the IO::All is currently open for input/output.
1024 * is_pipe
1026 Returns boolean telling whether or not the IO::All object repre‐
1027 sents a pipe operation.
1028 * is_readable
1030 Returns true if file or directory is readable.
1031 * is_socket
1033 Returns boolean telling whether or not the IO::All object repre‐
1034 sents a socket.
1035 * is_stdio
1037 Returns boolean telling whether or not the IO::All object repre‐
1038 sents a STDIO file handle.
1039 * is_string
1041 Returns boolean telling whether or not the IO::All object repre‐
1042 sents an IO::String object.
1043 * is_temp
1045 Returns boolean telling whether or not the IO::All object repre‐
1046 sents a temporary file.
1047 * is_writable
1049 Returns true if file or directory is writable. Can also be spelled
1050 as "is_writeable".
1051 * length
1053 Return the length of the internal buffer.
1054 * mkdir
1056 Create the directory represented by the object.
1057 * mkpath
1059 Create the directory represented by the object, when the path con‐
1060 tains more than one directory that doesn't exist. Proxy for
1061 File::Path::mkpath.
1062 * next
1064 For a directory, this will return a new IO::All object for each
1065 file or subdirectory in the directory. Return undef on EOD.
1066 * open
1068 Open the IO::All object. Takes two optional arguments "mode" and
1069 "perms", which can also be set ahead of time using the "mode" and
1070 "perms" methods.
1071 NOTE: Normally you won't need to call open (or mode/perms), since
1073 this happens automatically for most operations.
1074 * pathname
1076 Return the absolute or relative pathname for a file or directory,
1077 depending on whether object is in "absolute" or "relative" mode.
1078 * print
1080 Proxy for IO::Handle::print
1081 * printf
1083 Proxy for IO::Handle::printf
1084 * println
1086 Same as print, but adds newline to each argument unless it already
1087 ends with one.
1088 * put
1090 Perform an LWP PUT request manually.
1091 * read
1093 This method varies depending on its context. Read carefully (no pun
1094 intended).
1095 For a file, this will proxy IO::File::read. This means you must
1097 pass it a buffer, a length to read, and optionally a buffer offset
1098 for where to put the data that is read. The function returns the
1099 length actually read (which is zero at EOF).
1100 If you don't pass any arguments for a file, IO::All will use its
1102 own internal buffer, a default length, and the offset will always
1103 point at the end of the buffer. The buffer can be accessed with the
1104 "buffer" method. The length can be set with the "block_size"
1105 method. The default length is 1024 bytes. The "clear" method can be
1106 called to clear the buffer.
1107 For a directory, this will proxy IO::Dir::read.
1109 * readdir
1111 Similar to the Perl "readdir" builtin. In scalar context, return
1112 the next directory entry (ie file or directory name), or undef on
1113 end of directory. In list context, return all directory entries.
1114 Note that "readdir" does not return the special "." and ".."
1116 entries.
1117 * readline
1119 Same as "getline".
1120 * readlink
1122 Calls Perl's readlink function on the link represented by the
1123 object. Instead of returning the file path, it returns a new
1124 IO::All object using the file path.
1125 * recv
1127 Proxy for IO::Socket::recv
1128 * rename
1130 my $new = $io->rename('new-name');
1131 Calls Perl's rename function and returns an IO::All object for the
1133 renamed file. Returns false if the rename failed.
1134 * rewind
1136 Proxy for IO::Dir::rewind
1137 * rmdir
1139 Delete the directory represented by the IO::All object.
1140 * rmtree
1142 Delete the directory represented by the IO::All object and all the
1143 files and directories beneath it. Proxy for File::Path::rmtree.
1144 * scalar
1146 Deprecated. Same as "all()".
1147 * seek
1149 Proxy for IO::Handle::seek. If you use seek on an unopened file, it
1150 will be opened for both read and write.
1151 * send
1153 Proxy for IO::Socket::send
1154 * shutdown
1156 Proxy for IO::Socket::shutdown
1157 * slurp
1159 Read all file content in one operation. Returns the file content as
1160 a string. In list context returns every line in the file.
1161 * stat
1163 Proxy for IO::Handle::stat
1164 * sysread
1166 Proxy for IO::Handle::sysread
1167 * syswrite
1169 Proxy for IO::Handle::syswrite
1170 * tail
1172 Return the last 10 lines of a file. Takes an optional argument
1173 which is the number of lines to return. Works as expected in list
1174 and scalar context. Is subject to the current line separator.
1175 * tell
1177 Proxy for IO::Handle::tell
1178 * throw
1180 This is an internal method that gets called whenever there is an
1181 error. It could be useful to override it in a subclass, to provide
1182 more control in error handling.
1183 * touch
1185 Update the atime and mtime values for a file or directory. Creates
1186 an empty file if the file does not exist.
1187 * truncate
1189 Proxy for IO::Handle::truncate
1190 * type
1192 Returns a string indicated the type of io object. Possible values
1193 are:
1194 file
1196 dir
1197 link
1198 socket
1199 string
1200 pipe
1201 Returns undef if type is not determinable.
1203 * unlink
1205 Unlink (delete) the file represented by the IO::All object.
1206 NOTE: You can unlink a file after it is open, and continue using it
1208 until it is closed.
1209 * unlock
1211 Release a lock from an object that used the "lock" method.
1212 * utime
1214 Proxy for the utime Perl function.
1215 * write
1217 Opposite of "read" for file operations only.
1218 NOTE: When used with the automatic internal buffer, "write" will
1220 clear the buffer after writing it.
1221 Stat Methods
1223 This methods get individual values from a stat call on the file, direc‐
1225 tory or handle represented by th IO::All object.
1226 * atime
1228 Last access time in seconds since the epoch
1229 * blksize
1231 Preferred block size for file system I/O
1232 * blocks
1234 Actual number of blocks allocated
1235 * ctime
1237 Inode change time in seconds since the epoch
1238 * device
1240 Device number of filesystem
1241 * device_id
1243 Device identifier for special files only
1244 * gid
1246 Numeric group id of file's owner
1247 * inode
1249 Inode number
1250 * modes
1252 File mode - type and permissions
1253 * mtime
1255 Last modify time in seconds since the epoch
1256 * nlink
1258 Number of hard links to the file
1259 * size
1261 Total size of file in bytes
1262 * uid
1264 Numeric user id of file's owner
1265 File::Spec Methods
1267 These methods are all adaptations from File::Spec. Each method actually
1269 does call the matching File::Spec method, but the arguments and return
1270 values differ slightly. Instead of being file and directory names, they
1271 are IO::All objects. Since IO::All objects stringify to their names,
1272 you can generally use the methods just like File::Spec.
1273 * abs2rel
1275 Returns the relative path for the absolute path in the IO::All
1276 object. Can take an optional argument indicating the base path.
1277 * canonpath
1279 Returns the canonical path for the IO::All object.
1280 * case_tolerant
1282 Returns 0 or 1 indicating whether the file system is case tolerant.
1283 Since an active IO::All object is not needed for this function, you
1284 can code it like:
1285 IO::All->case_tolerant;
1287 or more simply:
1289 io->case_tolerant;
1291 * catdir
1293 Concatenate the directory components together, and return a new
1294 IO::All object representing the resulting directory.
1295 * catfile
1297 Concatenate the directory and file components together, and return
1298 a new IO::All object representing the resulting file.
1299 my $contents = io->catfile(qw(dir subdir file))->slurp;
1301 This is a very portable way to read "dir/subdir/file".
1303 * catpath
1305 Concatenate the volume, directory and file components together, and
1306 return a new IO::All object representing the resulting file.
1307 * curdir
1309 Returns an IO::All object representing the current directory.
1310 * devnull
1312 Returns an IO::All object representing the /dev/null file.
1313 * is_absolute
1315 Returns 0 or 1 indicating whether the "name" field of the IO::All
1316 object is an absolute path.
1317 * join
1319 Same as "catfile".
1320 * path
1322 Returns a list of IO::All directory objects for each directory in
1323 your path.
1324 * rel2abs
1326 Returns the absolute path for the relative path in the IO::All
1327 object. Can take an optional argument indicating the base path.
1328 * rootdir
1330 Returns an IO::All object representing the root directory on your
1331 file system.
1332 * splitdir
1334 Returns a list of the directory components of a path in an IO::All
1335 object.
1336 * splitpath
1338 Returns a volume directory and file component of a path in an
1339 IO::All object.
1340 * tmpdir
1342 Returns an IO::All object representing a temporary directory on
1343 your file system.
1344 * updir
1346 Returns an IO::All object representing the current parent direc‐
1347 tory.
1348
1350 · Each IO::All object gets reblessed into an IO::All::* object as
1351 soon as IO::All can determine what type of object it should be.
1352 Sometimes it gets reblessed more than once:
1353 my $io = io('mydbm.db');
1355 $io->dbm('DB_File');
1356 $io->{foo} = 'bar';
1357 In the first statement, $io has a reference value of
1359 'IO::All::File', if "mydbm.db" exists. In the second statement, the
1360 object is reblessed into class 'IO::All::DBM'.
1361 · An IO::All object will automatically be opened as soon as there is
1363 enough contextual information to know what type of object it is,
1364 and what mode it should be opened for. This is usually when the
1365 first read or write operation is invoked but might be sooner.
1366 · The mode for an object to be opened with is determined heuristi‐
1368 cally unless specified explicitly.
1369 · For input, IO::All objects will automatically be closed after EOF
1371 (or EOD). For output, the object closes when it goes out of scope.
1372 To keep input objects from closing at EOF, do this:
1374 $io->autoclose(0);
1376 · You can always call "open" and "close" explicitly, if you need that
1378 level of control. To test if an object is currently open, use the
1379 "is_open" method.
1380 · Overloaded operations return the target object, if one exists.
1382 This would set $xxx to the IO::All object:
1384 my $xxx = $contents > io('file.txt');
1386 While this would set $xxx to the content string:
1388 my $xxx = $contents < io('file.txt');
1390
1392 The goal of the IO::All project is to continually refine the module to
1393 be as simple and consistent to use as possible. Therefore, in the early
1394 stages of the project, I will not hesitate to break backwards compati‐
1395 bility with other versions of IO::All if I can find an easier and
1396 clearer way to do a particular thing.
1397 IO is tricky stuff. There is definitely more work to be done. On the
1399 other hand, this module relies heavily on very stable existing IO mod‐
1400 ules; so it may work fairly well.
1401 I am sure you will find many unexpected "features". Please send all
1403 problems, ideas and suggestions to ingy@cpan.org.
1404 Known Bugs and Deficiencies
1406 Not all possible combinations of objects and methods have been tested.
1408 There are many many combinations. All of the examples have been tested.
1409 If you find a bug with a particular combination of calls, let me know.
1410 If you call a method that does not make sense for a particular object,
1412 the result probably won't make sense. Little attempt is made to check
1413 for improper usage.
1414
1416 IO::Handle, IO::File, IO::Dir, IO::Socket, IO::String, File::Spec,
1417 File::Path, File::ReadBackwards, Tie::File
1418
1420 A lot of people have sent in suggestions, that have become a part of
1421 IO::All. Thank you.
1422 Special thanks to Ian Langworth for continued testing and patching.
1424 Thank you Simon Cozens for tipping me off to the overloading possibili‐
1426 ties.
1427 Finally, thanks to Autrijus Tang, for always having one more good idea.
1429 (It seems IO::All of it to a lot of people!)
1431
1433 Ingy döt Net <ingy@cpan.org>
1434
1436 Copyright (c) 2004. Brian Ingerson. All rights reserved.
1437 Copyright (c) 2006. Ingy döt Net. All rights reserved.
1439 This program is free software; you can redistribute it and/or modify it
1441 under the same terms as Perl itself.
1442 See <http://www.perl.com/perl/misc/Artistic.html>
1444perl v5.8.8 2007-04-07 IO::All(3)