package FileHandle; use 5.006; use strict; our($VERSION, @ISA, @EXPORT, @EXPORT_OK); $VERSION = "2.03"; require IO::File; @ISA = qw(IO::File); @EXPORT = qw(_IOFBF _IOLBF _IONBF); @EXPORT_OK = qw( pipe autoflush output_field_separator output_record_separator input_record_separator input_line_number format_page_number format_lines_per_page format_lines_left format_name format_top_name format_line_break_characters format_formfeed print printf getline getlines ); # # Everything we're willing to export, we must first import. # IO::Handle->import( grep { !defined(&$_) } @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 = IO::Handle->new; my $w = IO::Handle->new; CORE::pipe($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