xref: /onnv-gate/usr/src/cmd/perl/5.8.4/distrib/ext/IO/lib/IO/File.pm (revision 0:68f95e015346)
1#
2
3package IO::File;
4
5=head1 NAME
6
7IO::File - supply object methods for filehandles
8
9=head1 SYNOPSIS
10
11    use IO::File;
12
13    $fh = new IO::File;
14    if ($fh->open("< file")) {
15        print <$fh>;
16        $fh->close;
17    }
18
19    $fh = new IO::File "> file";
20    if (defined $fh) {
21        print $fh "bar\n";
22        $fh->close;
23    }
24
25    $fh = new IO::File "file", "r";
26    if (defined $fh) {
27        print <$fh>;
28        undef $fh;       # automatically closes the file
29    }
30
31    $fh = new IO::File "file", O_WRONLY|O_APPEND;
32    if (defined $fh) {
33        print $fh "corge\n";
34
35        $pos = $fh->getpos;
36        $fh->setpos($pos);
37
38        undef $fh;       # automatically closes the file
39    }
40
41    autoflush STDOUT 1;
42
43=head1 DESCRIPTION
44
45C<IO::File> inherits from C<IO::Handle> and C<IO::Seekable>. It extends
46these classes with methods that are specific to file handles.
47
48=head1 CONSTRUCTOR
49
50=over 4
51
52=item new ( FILENAME [,MODE [,PERMS]] )
53
54Creates an C<IO::File>.  If it receives any parameters, they are passed to
55the method C<open>; if the open fails, the object is destroyed.  Otherwise,
56it is returned to the caller.
57
58=item new_tmpfile
59
60Creates an C<IO::File> opened for read/write on a newly created temporary
61file.  On systems where this is possible, the temporary file is anonymous
62(i.e. it is unlinked after creation, but held open).  If the temporary
63file cannot be created or opened, the C<IO::File> object is destroyed.
64Otherwise, it is returned to the caller.
65
66=back
67
68=head1 METHODS
69
70=over 4
71
72=item open( FILENAME [,MODE [,PERMS]] )
73
74=item open( FILENAME, IOLAYERS )
75
76C<open> accepts one, two or three parameters.  With one parameter,
77it is just a front end for the built-in C<open> function.  With two or three
78parameters, the first parameter is a filename that may include
79whitespace or other special characters, and the second parameter is
80the open mode, optionally followed by a file permission value.
81
82If C<IO::File::open> receives a Perl mode string ("E<gt>", "+E<lt>", etc.)
83or an ANSI C fopen() mode string ("w", "r+", etc.), it uses the basic
84Perl C<open> operator (but protects any special characters).
85
86If C<IO::File::open> is given a numeric mode, it passes that mode
87and the optional permissions value to the Perl C<sysopen> operator.
88The permissions default to 0666.
89
90If C<IO::File::open> is given a mode that includes the C<:> character,
91it passes all the three arguments to the three-argument C<open> operator.
92
93For convenience, C<IO::File> exports the O_XXX constants from the
94Fcntl module, if this module is available.
95
96=back
97
98=head1 SEE ALSO
99
100L<perlfunc>,
101L<perlop/"I/O Operators">,
102L<IO::Handle>
103L<IO::Seekable>
104
105=head1 HISTORY
106
107Derived from FileHandle.pm by Graham Barr E<lt>F<gbarr@pobox.com>E<gt>.
108
109=cut
110
111use 5.006_001;
112use strict;
113our($VERSION, @EXPORT, @EXPORT_OK, @ISA);
114use Carp;
115use Symbol;
116use SelectSaver;
117use IO::Seekable;
118use File::Spec;
119
120require Exporter;
121
122@ISA = qw(IO::Handle IO::Seekable Exporter);
123
124$VERSION = "1.10";
125
126@EXPORT = @IO::Seekable::EXPORT;
127
128eval {
129    # Make all Fcntl O_XXX constants available for importing
130    require Fcntl;
131    my @O = grep /^O_/, @Fcntl::EXPORT;
132    Fcntl->import(@O);  # first we import what we want to export
133    push(@EXPORT, @O);
134};
135
136################################################
137## Constructor
138##
139
140sub new {
141    my $type = shift;
142    my $class = ref($type) || $type || "IO::File";
143    @_ >= 0 && @_ <= 3
144	or croak "usage: new $class [FILENAME [,MODE [,PERMS]]]";
145    my $fh = $class->SUPER::new();
146    if (@_) {
147	$fh->open(@_)
148	    or return undef;
149    }
150    $fh;
151}
152
153################################################
154## Open
155##
156
157sub open {
158    @_ >= 2 && @_ <= 4 or croak 'usage: $fh->open(FILENAME [,MODE [,PERMS]])';
159    my ($fh, $file) = @_;
160    if (@_ > 2) {
161	my ($mode, $perms) = @_[2, 3];
162	if ($mode =~ /^\d+$/) {
163	    defined $perms or $perms = 0666;
164	    return sysopen($fh, $file, $mode, $perms);
165	} elsif ($mode =~ /:/) {
166	    return open($fh, $mode, $file) if @_ == 3;
167	    croak 'usage: $fh->open(FILENAME, IOLAYERS)';
168	}
169	if (defined($file) && length($file)
170	    && ! File::Spec->file_name_is_absolute($file))
171	{
172	    $file = File::Spec->catfile(File::Spec->curdir(),$file);
173	}
174	$file = IO::Handle::_open_mode_string($mode) . " $file\0";
175    }
176    open($fh, $file);
177}
178
1791;
180