FM / pod

/usr/share/perl5/pod

Name	Size	Mode	Actions
perl.pod	16270	0644	edit dl rm
perl56delta.pod	107201	0644	edit dl rm
perl58delta.pod	115165	0644	edit dl rm
perl561delta.pod	124713	0644	edit dl rm
perl581delta.pod	38061	0644	edit dl rm
perl582delta.pod	4470	0644	edit dl rm
perl583delta.pod	6335	0644	edit dl rm
perl584delta.pod	7363	0644	edit dl rm
perl585delta.pod	5889	0644	edit dl rm
perl586delta.pod	4651	0644	edit dl rm
perl587delta.pod	8357	0644	edit dl rm
perl588delta.pod	25272	0644	edit dl rm
perl589delta.pod	53900	0644	edit dl rm
perl5004delta.pod	56240	0644	edit dl rm
perl5005delta.pod	34283	0644	edit dl rm
perl5100delta.pod	55535	0644	edit dl rm
perl5101delta.pod	43888	0644	edit dl rm
perl5120delta.pod	89272	0644	edit dl rm
perl5121delta.pod	10141	0644	edit dl rm
perl5122delta.pod	9603	0644	edit dl rm
perl5123delta.pod	4100	0644	edit dl rm
perl5124delta.pod	3672	0644	edit dl rm
perl5125delta.pod	7683	0644	edit dl rm
perl5140delta.pod	144324	0644	edit dl rm
perl5141delta.pod	7966	0644	edit dl rm
perl5142delta.pod	6892	0644	edit dl rm
perl5143delta.pod	7760	0644	edit dl rm
perl5144delta.pod	6327	0644	edit dl rm
perl5160delta.pod	133651	0644	edit dl rm
perl5161delta.pod	6142	0644	edit dl rm
perl5162delta.pod	3594	0644	edit dl rm
perl5163delta.pod	4085	0644	edit dl rm
perl5180delta.pod	119431	0644	edit dl rm
perl5181delta.pod	6595	0644	edit dl rm
perl5182delta.pod	5335	0644	edit dl rm
perl5184delta.pod	4642	0644	edit dl rm
perl5200delta.pod	115699	0644	edit dl rm
perl5201delta.pod	10899	0644	edit dl rm
perl5202delta.pod	12509	0644	edit dl rm
perl5203delta.pod	9392	0644	edit dl rm
perl5220delta.pod	130963	0644	edit dl rm
perl5221delta.pod	10767	0644	edit dl rm
perl5222delta.pod	12629	0644	edit dl rm
perl5223delta.pod	8456	0644	edit dl rm
perl5224delta.pod	4460	0644	edit dl rm
perl5240delta.pod	64927	0644	edit dl rm
perl5241delta.pod	8215	0644	edit dl rm
perl5242delta.pod	4113	0644	edit dl rm
perl5243delta.pod	11428	0644	edit dl rm
perl5244delta.pod	4510	0644	edit dl rm
perl5260delta.pod	101836	0644	edit dl rm
perl5261delta.pod	7927	0644	edit dl rm
perl5262delta.pod	7880	0644	edit dl rm
perl5263delta.pod	7063	0644	edit dl rm
perl5280delta.pod	72113	0644	edit dl rm
perlaix.pod	20437	0644	edit dl rm
perlamiga.pod	5749	0644	edit dl rm
perlandroid.pod	7871	0644	edit dl rm
perlapi.pod	443535	0644	edit dl rm
perlapio.pod	19285	0644	edit dl rm
perlartistic.pod	7010	0644	edit dl rm
perlbook.pod	8338	0644	edit dl rm
perlboot.pod	294	0644	edit dl rm
perlbot.pod	304	0644	edit dl rm
perlbs2000.pod	8058	0644	edit dl rm
perlcall.pod	56706	0644	edit dl rm
perlce.pod	14602	0644	edit dl rm
perlcheat.pod	4481	0644	edit dl rm
perlclib.pod	9619	0644	edit dl rm
perlcn.pod	4691	0644	edit dl rm
perlcommunity.pod	7217	0644	edit dl rm
perlcygwin.pod	27199	0644	edit dl rm
perldata.pod	46743	0644	edit dl rm
perldbmfilter.pod	4981	0644	edit dl rm
perldebguts.pod	38535	0644	edit dl rm
perldebtut.pod	22152	0644	edit dl rm
perldebug.pod	39258	0644	edit dl rm
perldelta.pod	7063	0644	edit dl rm
perldeprecation.pod	18169	0644	edit dl rm
perldiag.pod	284572	0644	edit dl rm
perldos.pod	10522	0644	edit dl rm
perldsc.pod	25614	0644	edit dl rm
perldtrace.pod	7958	0644	edit dl rm
perlebcdic.pod	84233	0644	edit dl rm
perlembed.pod	37196	0644	edit dl rm
perlexperiment.pod	7195	0644	edit dl rm
perlfork.pod	13355	0644	edit dl rm
perlform.pod	16608	0644	edit dl rm
perlfreebsd.pod	1610	0644	edit dl rm
perlfunc.pod	392957	0644	edit dl rm
perlgit.pod	33509	0644	edit dl rm
perlgpl.pod	13815	0644	edit dl rm
perlguts.pod	139329	0644	edit dl rm
perlhack.pod	40445	0644	edit dl rm
perlhacktips.pod	55509	0644	edit dl rm
perlhacktut.pod	6153	0644	edit dl rm
perlhaiku.pod	1508	0644	edit dl rm
perlhist.pod	53546	0644	edit dl rm
perlhpux.pod	30509	0644	edit dl rm
perlhurd.pod	1993	0644	edit dl rm
perlintern.pod	54572	0644	edit dl rm
perlinterp.pod	33687	0644	edit dl rm
perlintro.pod	22119	0644	edit dl rm
perliol.pod	34185	0644	edit dl rm
perlipc.pod	70829	0644	edit dl rm
perlirix.pod	4395	0644	edit dl rm
perljp.pod	7521	0644	edit dl rm
perlko.pod	12259	0644	edit dl rm
perllexwarn.pod	355	0644	edit dl rm
perllinux.pod	1488	0644	edit dl rm
perllocale.pod	68678	0644	edit dl rm
perllol.pod	9580	0644	edit dl rm
perlmacos.pod	1001	0644	edit dl rm
perlmacosx.pod	12060	0644	edit dl rm
perlmod.pod	26250	0644	edit dl rm
perlmodinstall.pod	12792	0644	edit dl rm
perlmodlib.pod	76482	0644	edit dl rm
perlmodstyle.pod	22575	0644	edit dl rm
perlmroapi.pod	3212	0644	edit dl rm
perlnetware.pod	6648	0644	edit dl rm
perlnewmod.pod	11036	0644	edit dl rm
perlnumber.pod	8353	0644	edit dl rm
perlobj.pod	35537	0644	edit dl rm
perlootut.pod	26783	0644	edit dl rm
perlop.pod	136252	0644	edit dl rm
perlopenbsd.pod	1204	0644	edit dl rm
perlopentut.pod	9455	0644	edit dl rm
perlos2.pod	93351	0644	edit dl rm
perlos390.pod	15674	0644	edit dl rm
perlos400.pod	4768	0644	edit dl rm
perlpacktut.pod	51282	0644	edit dl rm
perlperf.pod	49881	0644	edit dl rm
perlplan9.pod	5125	0644	edit dl rm
perlpod.pod	22196	0644	edit dl rm
perlpodspec.pod	68476	0644	edit dl rm
perlpolicy.pod	25629	0644	edit dl rm
perlport.pod	87602	0644	edit dl rm
perlpragma.pod	5176	0644	edit dl rm
perlqnx.pod	6673	0644	edit dl rm
perlre.pod	120901	0644	edit dl rm
perlreapi.pod	30334	0644	edit dl rm
perlrebackslash.pod	31817	0644	edit dl rm
perlrecharclass.pod	49029	0644	edit dl rm
perlref.pod	35304	0644	edit dl rm
perlreftut.pod	18790	0644	edit dl rm
perlreguts.pod	38328	0644	edit dl rm
perlrepository.pod	509	0644	edit dl rm
perlrequick.pod	18497	0644	edit dl rm
perlreref.pod	14744	0644	edit dl rm
perlretut.pod	121257	0644	edit dl rm
perlriscos.pod	1529	0644	edit dl rm
perlrun.pod	53550	0644	edit dl rm
perlsec.pod	26184	0644	edit dl rm
perlsolaris.pod	29822	0644	edit dl rm
perlsource.pod	6876	0644	edit dl rm
perlstyle.pod	8630	0644	edit dl rm
perlsub.pod	72967	0644	edit dl rm
perlsymbian.pod	15359	0644	edit dl rm
perlsyn.pod	44512	0644	edit dl rm
perlsynology.pod	7778	0644	edit dl rm
perlthrtut.pod	46459	0644	edit dl rm
perltie.pod	38607	0644	edit dl rm
perltoc.pod	694171	0644	edit dl rm
perltodo.pod	376	0644	edit dl rm
perltooc.pod	294	0644	edit dl rm
perltoot.pod	294	0644	edit dl rm
perltrap.pod	10620	0644	edit dl rm
perltru64.pod	8492	0644	edit dl rm
perltw.pod	4477	0644	edit dl rm
perlunicode.pod	82491	0644	edit dl rm
perlunicook.pod	25488	0644	edit dl rm
perlunifaq.pod	13647	0644	edit dl rm
perluniintro.pod	38340	0644	edit dl rm
perluniprops.pod	285306	0644	edit dl rm
perlunitut.pod	7951	0644	edit dl rm
perlutil.pod	7640	0644	edit dl rm
perlvar.pod	78364	0644	edit dl rm
perlvms.pod	50823	0644	edit dl rm
perlvos.pod	3843	0644	edit dl rm
perlwin32.pod	39298	0644	edit dl rm
perlxs.pod	78920	0644	edit dl rm
perlxstut.pod	50095	0644	edit dl rm
perlxstypemap.pod	24001	0644	edit dl rm

Edit: /usr/share/perl5/pod/perlopentut.pod (9455B)

=encoding utf8

=head1 NAME

perlopentut - simple recipes for opening files and pipes in Perl

=head1 DESCRIPTION

Whenever you do I/O on a file in Perl, you do so through what in Perl is
called a B<filehandle>.  A filehandle is an internal name for an external
file.  It is the job of the C<open> function to make the association
between the internal name and the external name, and it is the job
of the C<close> function to break that association.

For your convenience, Perl sets up a few special filehandles that are
already open when you run.  These include C<STDIN>, C<STDOUT>, C<STDERR>,
and C<ARGV>.  Since those are pre-opened, you can use them right away
without having to go to the trouble of opening them yourself:

print STDERR "This is a debugging message.\n";

print STDOUT "Please enter something: ";
    $response = <STDIN> // die "how come no input?";
    print STDOUT "Thank you!\n";

while (<ARGV>) { ... }

As you see from those examples, C<STDOUT> and C<STDERR> are output
handles, and C<STDIN> and C<ARGV> are input handles.  They are
in all capital letters because they are reserved to Perl, much
like the C<@ARGV> array and the C<%ENV> hash are.  Their external
associations were set up by your shell.

You will need to open every other filehandle on your own. Although there
are many variants, the most common way to call Perl's open() function
is with three arguments and one return value:

C<    I<OK> = open(I<HANDLE>, I<MODE>, I<PATHNAME>)>

Where:

=over

=item I<OK>

will be some defined value if the open succeeds, but
C<undef> if it fails;

=item I<HANDLE>

should be an undefined scalar variable to be filled in by the
C<open> function if it succeeds;

=item I<MODE>

is the access mode and the encoding format to open the file with;

=item I<PATHNAME>

is the external name of the file you want opened.

=back

Most of the complexity of the C<open> function lies in the many
possible values that the I<MODE> parameter can take on.

One last thing before we show you how to open files: opening
files does not (usually) automatically lock them in Perl.  See
L<perlfaq5> for how to lock.

=head1 Opening Text Files

=head2 Opening Text Files for Reading

If you want to read from a text file, first open it in
read-only mode like this:

my $filename = "/some/path/to/a/textfile/goes/here";
    my $encoding = ":encoding(UTF-8)";
    my $handle   = undef;     # this will be filled in on success

open($handle, "< $encoding", $filename)
        || die "$0: can't open $filename for reading: $!";

As with the shell, in Perl the C<< "<" >> is used to open the file in
read-only mode.  If it succeeds, Perl allocates a brand new filehandle for
you and fills in your previously undefined C<$handle> argument with a
reference to that handle.

Now you may use functions like C<readline>, C<read>, C<getc>, and
C<sysread> on that handle.  Probably the most common input function
is the one that looks like an operator:

$line = readline($handle);
    $line = <$handle>;          # same thing

Because the C<readline> function returns C<undef> at end of file or
upon error, you will sometimes see it used this way:

$line = <$handle>;
    if (defined $line) {
        # do something with $line
    }
    else {
        # $line is not valid, so skip it
    }

You can also just quickly C<die> on an undefined value this way:

$line = <$handle> // die "no input found";

However, if hitting EOF is an expected and normal event, you do not want to
exit simply because you have run out of input.  Instead, you probably just want
to exit an input loop.  You can then test to see if an actual error has caused
the loop to terminate, and act accordingly:

while (<$handle>) {
        # do something with data in $_
    }
    if ($!) {
        die "unexpected error while reading from $filename: $!";
    }

B<A Note on Encodings>: Having to specify the text encoding every time
might seem a bit of a bother.  To set up a default encoding for C<open> so
that you don't have to supply it each time, you can use the C<open> pragma:

use open qw< :encoding(UTF-8) >;

Once you've done that, you can safely omit the encoding part of the
open mode:

open($handle, "<", $filename)
        || die "$0: can't open $filename for reading: $!";

But never use the bare C<< "<" >> without having set up a default encoding
first.  Otherwise, Perl cannot know which of the many, many, many possible
flavors of text file you have, and Perl will have no idea how to correctly
map the data in your file into actual characters it can work with.  Other
common encoding formats including C<"ASCII">, C<"ISO-8859-1">,
C<"ISO-8859-15">, C<"Windows-1252">, C<"MacRoman">, and even C<"UTF-16LE">.
See L<perlunitut> for more about encodings.

=head2 Opening Text Files for Writing

When you want to write to a file, you first have to decide what to do about
any existing contents of that file.  You have two basic choices here: to
preserve or to clobber.

If you want to preserve any existing contents, then you want to open the file
in append mode.  As in the shell, in Perl you use C<<< ">>" >>> to open an
existing file in append mode.  C<<< ">>" >>> creates the file if it does not
already exist.

my $handle   = undef;
    my $filename = "/some/path/to/a/textfile/goes/here";
    my $encoding = ":encoding(UTF-8)";

open($handle, ">> $encoding", $filename)
        || die "$0: can't open $filename for appending: $!";

Now you can write to that filehandle using any of C<print>, C<printf>,
C<say>, C<write>, or C<syswrite>.

As noted above, if the file does not already exist, then the append-mode open
will create it for you.  But if the file does already exist, its contents are
safe from harm because you will be adding your new text past the end of the
old text.

On the other hand, sometimes you want to clobber whatever might already be
there.  To empty out a file before you start writing to it, you can open it
in write-only mode:

my $handle   = undef;
    my $filename = "/some/path/to/a/textfile/goes/here";
    my $encoding = ":encoding(UTF-8)";

open($handle, "> $encoding", $filename)
        || die "$0: can't open $filename in write-open mode: $!";

Here again Perl works just like the shell in that the C<< ">" >> clobbers
an existing file.

As with the append mode, when you open a file in write-only mode,
you can now write to that filehandle using any of C<print>, C<printf>,
C<say>, C<write>, or C<syswrite>.

What about read-write mode?  You should probably pretend it doesn't exist,
because opening text files in read-write mode is unlikely to do what you
would like.  See L<perlfaq5> for details.

=head1 Opening Binary Files

If the file to be opened contains binary data instead of text characters,
then the C<MODE> argument to C<open> is a little different.  Instead of
specifying the encoding, you tell Perl that your data are in raw bytes.

my $filename = "/some/path/to/a/binary/file/goes/here";
    my $encoding = ":raw :bytes"
    my $handle   = undef;     # this will be filled in on success

And then open as before, choosing C<<< "<" >>>, C<<< ">>" >>>, or
C<<< ">" >>> as needed:

open($handle, "< $encoding", $filename)
        || die "$0: can't open $filename for reading: $!";

open($handle, ">> $encoding", $filename)
        || die "$0: can't open $filename for appending: $!";

open($handle, "> $encoding", $filename)
        || die "$0: can't open $filename in write-open mode: $!";

Alternately, you can change to binary mode on an existing handle this way:

binmode($handle)    || die "cannot binmode handle";

This is especially handy for the handles that Perl has already opened for you.

binmode(STDIN)      || die "cannot binmode STDIN";
    binmode(STDOUT)     || die "cannot binmode STDOUT";

You can also pass C<binmode> an explicit encoding to change it on the fly.
This isn't exactly "binary" mode, but we still use C<binmode> to do it:

binmode(STDIN,  ":encoding(MacRoman)") || die "cannot binmode STDIN";
  binmode(STDOUT, ":encoding(UTF-8)")    || die "cannot binmode STDOUT";

Once you have your binary file properly opened in the right mode, you can
use all the same Perl I/O functions as you used on text files.  However,
you may wish to use the fixed-size C<read> instead of the variable-sized
C<readline> for your input.

Here's an example of how to copy a binary file:

my $BUFSIZ   = 64 * (2 ** 10);
    my $name_in  = "/some/input/file";
    my $name_out = "/some/output/flie";

my($in_fh, $out_fh, $buffer);

open($in_fh,  "<", $name_in)
        || die "$0: cannot open $name_in for reading: $!";
    open($out_fh, ">", $name_out)
        || die "$0: cannot open $name_out for writing: $!";

for my $fh ($in_fh, $out_fh)  {
        binmode($fh)               || die "binmode failed";
    }

while (read($in_fh, $buffer, $BUFSIZ)) {
        unless (print $out_fh $buffer) {
            die "couldn't write to $name_out: $!";
        }
    }

close($in_fh)       || die "couldn't close $name_in: $!";
    close($out_fh)      || die "couldn't close $name_out: $!";

=head1 Opening Pipes

To be announced.

=head1 Low-level File Opens via sysopen

To be announced.  Or deleted.

=head1 SEE ALSO

To be announced.

=head1 AUTHOR and COPYRIGHT

This documentation is free; you can redistribute it and/or modify it under
the same terms as Perl itself.

cmd: