mirror of
https://git.savannah.gnu.org/git/parallel.git
synced 2024-11-24 15:07:55 +00:00
263 lines
6.6 KiB
Perl
263 lines
6.6 KiB
Perl
package FileHandle;
|
|
|
|
use 5.006;
|
|
use strict;
|
|
our($VERSION, @ISA, @EXPORT, @EXPORT_OK);
|
|
|
|
$VERSION = "2.02";
|
|
|
|
require IO::File;
|
|
@ISA = qw(IO::File);
|
|
|
|
@EXPORT = qw(_IOFBF _IOLBF _IONBF);
|
|
|
|
@EXPORT_OK = qw(
|
|
pipe
|
|
|
|
autoflush
|
|
output_field_separator
|
|
output_record_separator
|
|
input_record_separator
|
|
input_line_number
|
|
format_page_number
|
|
format_lines_per_page
|
|
format_lines_left
|
|
format_name
|
|
format_top_name
|
|
format_line_break_characters
|
|
format_formfeed
|
|
|
|
print
|
|
printf
|
|
getline
|
|
getlines
|
|
);
|
|
|
|
#
|
|
# Everything we're willing to export, we must first import.
|
|
#
|
|
import IO::Handle grep { !defined(&$_) } @EXPORT, @EXPORT_OK;
|
|
|
|
#
|
|
# Some people call "FileHandle::function", so all the functions
|
|
# that were in the old FileHandle class must be imported, too.
|
|
#
|
|
{
|
|
no strict 'refs';
|
|
|
|
my %import = (
|
|
'IO::Handle' =>
|
|
[qw(DESTROY new_from_fd fdopen close fileno getc ungetc gets
|
|
eof flush error clearerr setbuf setvbuf _open_mode_string)],
|
|
'IO::Seekable' =>
|
|
[qw(seek tell getpos setpos)],
|
|
'IO::File' =>
|
|
[qw(new new_tmpfile open)]
|
|
);
|
|
for my $pkg (keys %import) {
|
|
for my $func (@{$import{$pkg}}) {
|
|
my $c = *{"${pkg}::$func"}{CODE}
|
|
or die "${pkg}::$func missing";
|
|
*$func = $c;
|
|
}
|
|
}
|
|
}
|
|
|
|
#
|
|
# Specialized importer for Fcntl magic.
|
|
#
|
|
sub import {
|
|
my $pkg = shift;
|
|
my $callpkg = caller;
|
|
require Exporter;
|
|
Exporter::export($pkg, $callpkg, @_);
|
|
|
|
#
|
|
# If the Fcntl extension is available,
|
|
# export its constants.
|
|
#
|
|
eval {
|
|
require Fcntl;
|
|
Exporter::export('Fcntl', $callpkg);
|
|
};
|
|
}
|
|
|
|
################################################
|
|
# This is the only exported function we define;
|
|
# the rest come from other classes.
|
|
#
|
|
|
|
sub pipe {
|
|
my $r = new IO::Handle;
|
|
my $w = new IO::Handle;
|
|
CORE::pipe($r, $w) or return undef;
|
|
($r, $w);
|
|
}
|
|
|
|
# Rebless standard file handles
|
|
bless *STDIN{IO}, "FileHandle" if ref *STDIN{IO} eq "IO::Handle";
|
|
bless *STDOUT{IO}, "FileHandle" if ref *STDOUT{IO} eq "IO::Handle";
|
|
bless *STDERR{IO}, "FileHandle" if ref *STDERR{IO} eq "IO::Handle";
|
|
|
|
1;
|
|
|
|
__END__
|
|
|
|
=head1 NAME
|
|
|
|
FileHandle - supply object methods for filehandles
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
use FileHandle;
|
|
|
|
$fh = FileHandle->new;
|
|
if ($fh->open("< file")) {
|
|
print <$fh>;
|
|
$fh->close;
|
|
}
|
|
|
|
$fh = FileHandle->new("> FOO");
|
|
if (defined $fh) {
|
|
print $fh "bar\n";
|
|
$fh->close;
|
|
}
|
|
|
|
$fh = FileHandle->new("file", "r");
|
|
if (defined $fh) {
|
|
print <$fh>;
|
|
undef $fh; # automatically closes the file
|
|
}
|
|
|
|
$fh = FileHandle->new("file", O_WRONLY|O_APPEND);
|
|
if (defined $fh) {
|
|
print $fh "corge\n";
|
|
undef $fh; # automatically closes the file
|
|
}
|
|
|
|
$pos = $fh->getpos;
|
|
$fh->setpos($pos);
|
|
|
|
$fh->setvbuf($buffer_var, _IOLBF, 1024);
|
|
|
|
($readfh, $writefh) = FileHandle::pipe;
|
|
|
|
autoflush STDOUT 1;
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
NOTE: This class is now a front-end to the IO::* classes.
|
|
|
|
C<FileHandle::new> creates a C<FileHandle>, which is a reference to a
|
|
newly created symbol (see the C<Symbol> package). If it receives any
|
|
parameters, they are passed to C<FileHandle::open>; if the open fails,
|
|
the C<FileHandle> object is destroyed. Otherwise, it is returned to
|
|
the caller.
|
|
|
|
C<FileHandle::new_from_fd> creates a C<FileHandle> like C<new> does.
|
|
It requires two parameters, which are passed to C<FileHandle::fdopen>;
|
|
if the fdopen fails, the C<FileHandle> object is destroyed.
|
|
Otherwise, it is returned to the caller.
|
|
|
|
C<FileHandle::open> accepts one parameter or two. With one parameter,
|
|
it is just a front end for the built-in C<open> function. With two
|
|
parameters, the first parameter is a filename that may include
|
|
whitespace or other special characters, and the second parameter is
|
|
the open mode, optionally followed by a file permission value.
|
|
|
|
If C<FileHandle::open> receives a Perl mode string (">", "+<", etc.)
|
|
or a POSIX fopen() mode string ("w", "r+", etc.), it uses the basic
|
|
Perl C<open> operator.
|
|
|
|
If C<FileHandle::open> is given a numeric mode, it passes that mode
|
|
and the optional permissions value to the Perl C<sysopen> operator.
|
|
For convenience, C<FileHandle::import> tries to import the O_XXX
|
|
constants from the Fcntl module. If dynamic loading is not available,
|
|
this may fail, but the rest of FileHandle will still work.
|
|
|
|
C<FileHandle::fdopen> is like C<open> except that its first parameter
|
|
is not a filename but rather a file handle name, a FileHandle object,
|
|
or a file descriptor number.
|
|
|
|
If the C functions fgetpos() and fsetpos() are available, then
|
|
C<FileHandle::getpos> returns an opaque value that represents the
|
|
current position of the FileHandle, and C<FileHandle::setpos> uses
|
|
that value to return to a previously visited position.
|
|
|
|
If the C function setvbuf() is available, then C<FileHandle::setvbuf>
|
|
sets the buffering policy for the FileHandle. The calling sequence
|
|
for the Perl function is the same as its C counterpart, including the
|
|
macros C<_IOFBF>, C<_IOLBF>, and C<_IONBF>, except that the buffer
|
|
parameter specifies a scalar variable to use as a buffer. WARNING: A
|
|
variable used as a buffer by C<FileHandle::setvbuf> must not be
|
|
modified in any way until the FileHandle is closed or until
|
|
C<FileHandle::setvbuf> is called again, or memory corruption may
|
|
result!
|
|
|
|
See L<perlfunc> for complete descriptions of each of the following
|
|
supported C<FileHandle> methods, which are just front ends for the
|
|
corresponding built-in functions:
|
|
|
|
close
|
|
fileno
|
|
getc
|
|
gets
|
|
eof
|
|
clearerr
|
|
seek
|
|
tell
|
|
|
|
See L<perlvar> for complete descriptions of each of the following
|
|
supported C<FileHandle> methods:
|
|
|
|
autoflush
|
|
output_field_separator
|
|
output_record_separator
|
|
input_record_separator
|
|
input_line_number
|
|
format_page_number
|
|
format_lines_per_page
|
|
format_lines_left
|
|
format_name
|
|
format_top_name
|
|
format_line_break_characters
|
|
format_formfeed
|
|
|
|
Furthermore, for doing normal I/O you might need these:
|
|
|
|
=over 4
|
|
|
|
=item $fh->print
|
|
|
|
See L<perlfunc/print>.
|
|
|
|
=item $fh->printf
|
|
|
|
See L<perlfunc/printf>.
|
|
|
|
=item $fh->getline
|
|
|
|
This works like <$fh> described in L<perlop/"I/O Operators">
|
|
except that it's more readable and can be safely called in a
|
|
list context but still returns just one line.
|
|
|
|
=item $fh->getlines
|
|
|
|
This works like <$fh> when called in a list context to
|
|
read all the remaining lines in a file, except that it's more readable.
|
|
It will also croak() if accidentally called in a scalar context.
|
|
|
|
=back
|
|
|
|
There are many other functions available since FileHandle is descended
|
|
from IO::File, IO::Seekable, and IO::Handle. Please see those
|
|
respective pages for documentation on more functions.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
The B<IO> extension,
|
|
L<perlfunc>,
|
|
L<perlop/"I/O Operators">.
|
|
|
|
=cut
|