CD Actual Thematic 7: Programming/CDAT7.iso/Share/Editores/Perl5/perl/bin/lwp-rget

Text File | 1997-08-10 | 7.9 KB | 319 lines

#perl -w
    eval 'exec perl -S $0 "$@"'
    if 0;

=head1 NAME

lwp-rget - Retrieve WWW documents recursively

=head1 SYNOPSIS

 lwp-rget [--verbose] [--depth=N] [--limit=N] [--prefix=URL] <URL>
 lwp-rget --version

=head1 DESCRIPTION

This program will retrieve a document and store it in a local file.  It
will follow any links found in the document and store these documents
as well, patching links so that they refer to these local copies.
This process continues until there are no more unvisited links or the
process is stopped by the one or more of the limits which can be
controlled by the command line arguments.

This program is useful if you want to make a local copy of a
collection of documents or want to do web reading off-line.

All documents are stored as plain files in the current directory. The
file names chosen are derived from the last component of URL paths.

The options are:

=over 3

=item --depth=I<n>

Limit the recursive level. Embedded images are always loaded, even if
they fall outside the I<--depth>. This means that one can use
I<--depth=0> in order to fetch a single document together with all
inline graphics.

The default depth is 5.

=item --limit=I<n>

Limit the number of documents to get.  The default limit is 50.

=item --prefix=I<url_prefix>

Limit the links to follow. Only URLs that start the prefix string are
followed.

The default prefix is set as the "directory" of the initial URL to
follow.  For instance if we start lwp-rget with the URL
C<http://www.sn.no/foo/bar.html>, then prefix will be set to
C<http://www.sn.no/foo/>.

Use C<--prefix=''> if you don't want the fetching to be limited by any
prefix.

=item --sleep=I<n>

Sleep I<n> seconds before retrieving each document. This options allows
you to go slowly, not loading the server you visiting too much.

=item --verbose

Make more noise while running.

=item --quiet

Don't make any noise.

=item --version

Print program version number and quit.

=item --help

Print the usage message and quit.

=back

Before the program exits the name of the file, where the initial URL
is stored, is printed on stdout.  All used filenames are also printed
on stderr as they are loaded.  This printing can be suppressed with
the I<--quiet> option.

=head1 SEE ALSO

L<lwp-request>, L<LWP>

=head1 AUTHOR

Gisle Aas <[e-mail]>

=cut

use strict;

use Getopt::Long;
use URI::URL;
use LWP::MediaTypes qw(media_suffix);

use vars qw($VERSION);
use vars qw($MAX_DEPTH $MAX_DOCS $PREFIX $VERBOSE $QUIET $SLEEP);

$0 =~ s|.*/||;  # only basename left
$VERSION = sprintf("%d.%02d", q$Revision: 1.10 $ =~ /(\d+)\.(\d+)/);

#$Getopt::Long::debug = 1;
#$Getopt::Long::ignorecase = 0;

# Defaults
$MAX_DEPTH = 5;
$MAX_DOCS  = 50;

GetOptions('version'  => \&print_version,
       'help'     => \&usage,
       'depth=i'  => \$MAX_DEPTH,
       'limit=i'  => \$MAX_DOCS,
       'verbose!' => \$VERBOSE,
           'quiet!'   => \$QUIET,
       'sleep=i'  => \$SLEEP,
       'prefix:s' => \$PREFIX,
      ) || usage();

sub print_version {
    require LWP;
    my $DISTNAME = 'libwww-perl-' . LWP::Version();
    print <<"EOT";
This is lwp-rget version $VERSION ($DISTNAME)

Copyright 1996, Gisle Aas.

This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
EOT
    exit 0;
}

my $start_url = shift || usage();
usage() if @ARGV;

require LWP::UserAgent;
my $ua = new LWP::UserAgent;
$ua->agent("$0/$VERSION " . $ua->agent);
$ua->env_proxy;

unless (defined $PREFIX) {
    $PREFIX = url($start_url);   # limit to URLs below this one
    eval {
    $PREFIX->eparams(undef);
    $PREFIX->equery(undef);
    };

    $_ = $PREFIX->epath;
    s|[^/]+$||;
    $PREFIX->epath($_);
    $PREFIX = $PREFIX->as_string;
}


print <<"" if $VERBOSE;
START     = $start_url
MAX_DEPTH = $MAX_DEPTH
MAX_DOCS  = $MAX_DOCS
PREFIX    = $PREFIX


my $no_docs = 0;
my %seen = ();     # mapping from URL => local_file

my $filename = fetch($start_url);
print "$filename\n" unless $QUIET;

sub fetch
{
    my($url, $type, $depth) = @_;
    $url = url($url) unless ref($url);
    $type  ||= 'a';
    $type = 'img' if $type eq 'body';  # might be the background attribute
    $depth ||= 0;

    # Print the URL before we start checking...
    my $out = (" " x $depth) . $url . " ";
    $out .= "." x (60 - length($out));
    print STDERR $out . " " if $VERBOSE;

    # Can't get mailto things
    if ($url->scheme eq 'mailto') {
    print STDERR "*skipping mailto*\n" if $VERBOSE;
    return $url->as_string;
    }

    # The $plain_url is a URL without the fragment part
    my $plain_url = $url->clone;
    $plain_url->frag(undef);

    # If we already have it, then there is nothing to be done
    my $seen = $seen{$plain_url->as_string};
    if ($seen) {
    my $frag = $url->frag;
    $seen .= "#$frag" if defined($frag);
    print STDERR "$seen (again)\n" if $VERBOSE;
    return $seen;
    }

    # Too much or too deep
    if ($depth > $MAX_DEPTH and $type ne 'img') {
    print STDERR "*too deep*\n" if $VERBOSE;
    return $url;
    }
    if ($no_docs > $MAX_DOCS) {
    print STDERR "*too many*\n" if $VERBOSE;
    return $url;
    }

    # Check PREFIX, but not for <IMG ...> links
    if ($type ne 'img' and  $url->as_string !~ /^\Q$PREFIX/o) {
    print STDERR "*outsider*\n" if $VERBOSE;
    return $url->as_string;
    }

    # Fetch document
    $no_docs++;
    sleep($SLEEP) if $SLEEP;
    my $res = $ua->request(HTTP::Request->new(GET => $url));

    # Check outcome
    if ($res->is_success) {
    my $doc = $res->content;
    my $ct = $res->content_type;
    my $name = find_name($res->request->url, $ct);
    print STDERR "$name\n" unless $QUIET;
    $seen{$plain_url->as_string} = $name;

    # If the file is HTML, then we look for internal links
    if ($ct eq "text/html") {
        # Save an unprosessed version of the HTML document.  This
        # both reserves the name used, and it also ensures that we
        # don't loose everything if this program is killed before
        # we finish.
        save($name, $doc);
        my $base = $res->base;
        # Follow and substitute links...
        $doc =~ s/(<\s*(img|a|body)\b[^>]+\b(?:src|href|background)\s*=\s*)(["']?)([^>\s]+)\3/new_link($1, lc($2), $3, $4, $base, $depth+1)/gie;       #"; # help emacs
    }
    save($name, $doc);
    return $name;
    } else {
    print STDERR $res->code . " " . $res->message . "\n" if $VERBOSE;
    $seen{$plain_url->as_string} = "*BAD*";
    return "*BAD*";
    }
}

sub new_link
{
    my($pre, $type, $quote, $url, $base, $depth) = @_;
    $url = url($url, $base)->abs;
    $pre . $quote . fetch($url, $type, $depth) . $quote;
}

sub find_name
{
    my($url, $type) = @_;
    #print "find_name($url, $type)\n";
    $url = url($url) unless ref($url);

    my $path = $url->path;

    # trim path until only the basename is left
    $path =~ s|.*/||;
    $path =~ s|\..*||;
    $path = "index" unless length($path);

    my $extra = "";  # something to make the name unique
    my $suffix = media_suffix($type);

    while (1) {
    # Construct a new file name
    my $file = $path . $extra;
    $file .= ".$suffix" if $suffix;
    # Check if it is unique
    return $file unless -f $file;

    # Try something extra
    unless ($extra) {
        $extra = "001";
        next;
    }
    $extra++;
    }
}


sub save
{
    my $name = shift;
    #print "save($name,...)\n";
    open(FILE, ">$name") || die "Can't save $name: $!";
    print FILE $_[0];
    close(FILE);
}

sub usage
{
    die <<"";
Usage: $0 [options] <URL>
Allowed options are:
  --depth=N         Maximum depth to traverse (default is $MAX_DEPTH)
  --limit=N         A limit on the number documents to get (default is $MAX_DOCS)
  --version         Print version number and quit
  --verbose         More output
  --quiet           No output
  --sleep=SECS      Sleep between gets, ie. go slowly
  --prefix=PREFIX   Limit URLs to follow to those which begin with PREFIX

}