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1997-11-25
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#
# $Id: Simple.pm,v 1.26 1997/11/25 16:11:27 aas Exp $
=head1 NAME
get, head, getprint, getstore, mirror - Procedural LWP interface
=head1 SYNOPSIS
perl -MLWP::Simple -e 'getprint "http://www.sn.no"'
use LWP::Simple;
$content = get("http://www.sn.no/")
if (mirror("http://www.sn.no/", "foo") == RC_NOT_MODIFIED) {
...
}
if (is_success(getprint("http://www.sn.no/"))) {
...
}
=head1 DESCRIPTION
This interface is intended for those who want a simplified view of the
libwww-perl library. It should also be suitable for one-liners. If
you need more control or access to the header fields in the requests
sent and responses received you should use the full object oriented
interface provided by the C<LWP::UserAgent> module.
The following functions are provided (and exported) by this module:
=over 3
=item get($url)
The get() function will fetch the document identified by the given URL
and return it. It returns C<undef> if it fails. The $url argument can
be either a simple string or a reference to a URI::URL object.
You will not be able to examine the response code or response headers
(like 'Content-Type') when you are accessing the web using this
function. If you need this information you should use the full OO
interface (see L<LWP::UserAgent>).
=item head($url)
Get document headers. Returns the following 5 values if successful:
($content_type, $document_length, $modified_time, $expires, $server)
Returns an empty list if it fails. In scalar context returns TRUE if
successful.
=item getprint($url)
Get and print a document identified by a URL. The document is printed
on STDOUT as data is received from the network. If the request fails,
then the status code and message is printed on STDERR. The return
value is the HTTP response code.
=item getstore($url, $file)
Gets a document identified by a URL and stores it in the file. The
return value is the HTTP response code.
=item mirror($url, $file)
Get and store a document identified by a URL, using
I<If-modified-since>, and checking of the I<Content-Length>. Returns
the HTTP response code.
=back
This module also exports the HTTP::Status constants and procedures.
These can be used when you check the response code from getprint(),
getstore() and mirror(). The constants are:
RC_CONTINUE
RC_SWITCHING_PROTOCOLS
RC_OK
RC_CREATED
RC_ACCEPTED
RC_NON_AUTHORITATIVE_INFORMATION
RC_NO_CONTENT
RC_RESET_CONTENT
RC_PARTIAL_CONTENT
RC_MULTIPLE_CHOICES
RC_MOVED_PERMANENTLY
RC_MOVED_TEMPORARILY
RC_SEE_OTHER
RC_NOT_MODIFIED
RC_USE_PROXY
RC_BAD_REQUEST
RC_UNAUTHORIZED
RC_PAYMENT_REQUIRED
RC_FORBIDDEN
RC_NOT_FOUND
RC_METHOD_NOT_ALLOWED
RC_NOT_ACCEPTABLE
RC_PROXY_AUTHENTICATION_REQUIRED
RC_REQUEST_TIMEOUT
RC_CONFLICT
RC_GONE
RC_LENGTH_REQUIRED
RC_PRECONDITION_FAILED
RC_REQUEST_ENTITY_TOO_LARGE
RC_REQUEST_URI_TOO_LARGE
RC_UNSUPPORTED_MEDIA_TYPE
RC_INTERNAL_SERVER_ERROR
RC_NOT_IMPLEMENTED
RC_BAD_GATEWAY
RC_SERVICE_UNAVAILABLE
RC_GATEWAY_TIMEOUT
RC_HTTP_VERSION_NOT_SUPPORTED
The HTTP::Status classification functions are:
=over 3
=item is_success($rc)
Check if response code indicated successfull request.
=item is_error($rc)
Check if response code indicated that an error occured.
=back
The module will also export the LWP::UserAgent object as C<$ua> if you
ask for it explicitly.
The user agent created by this module will identify itself as
"LWP::Simple/#.##" (where "#.##" is the libwww-perl version number)
and will initialize its proxy defaults from the environment (by
calling $ua->env_proxy).
=head1 SEE ALSO
L<LWP>, L<LWP::UserAgent>, L<HTTP::Status>, L<lwp-request>,
L<lwp-mirror>
=cut
package LWP::Simple;
use strict;
use vars qw($ua %loop_check $FULL_LWP @EXPORT @EXPORT_OK $VERSION);
require Exporter;
@EXPORT = qw(get head getprint getstore mirror);
@EXPORT_OK = qw($ua);
# I really hate this. I was a bad idea to do it in the first place.
# Wonder how to get rid of it??? (It even makes LWP::Simple 7% slower
# for trivial tests)
use HTTP::Status;
push(@EXPORT, @HTTP::Status::EXPORT);
$VERSION = sprintf("%d.%02d", q$Revision: 1.26 $ =~ /(\d+)\.(\d+)/);
$FULL_LWP++ if grep {$_ eq "http_proxy"} keys %ENV;
sub import
{
my $pkg = shift;
my $callpkg = caller;
if (grep $_ eq '$ua', @_) {
$FULL_LWP++;
_init_ua();
}
Exporter::export($pkg, $callpkg, @_);
}
sub _init_ua
{
require LWP;
require LWP::UserAgent;
require HTTP::Status;
require HTTP::Date;
$ua = new LWP::UserAgent; # we create a global UserAgent object
my $ver = $LWP::VERSION = $LWP::VERSION; # avoid warning
$ua->agent("LWP::Simple/$LWP::VERSION");
$ua->env_proxy;
}
sub get ($)
{
%loop_check = ();
goto \&_get;
}
sub get_old ($)
{
my($url) = @_;
_init_ua() unless $ua;
my $request = HTTP::Request->new(GET => $url);
my $response = $ua->request($request);
return $response->content if $response->is_success;
return undef;
}
sub head ($)
{
my($url) = @_;
_init_ua() unless $ua;
my $request = HTTP::Request->new(HEAD => $url);
my $response = $ua->request($request);
if ($response->is_success) {
return $response unless wantarray;
return ($response->header('Content-Type'),
$response->header('Content-Length'),
HTTP::Date::str2time($response->header('Last-Modified')),
HTTP::Date::str2time($response->header('Expires')),
$response->header('Server'),
);
}
return;
}
sub getprint ($)
{
my($url) = @_;
_init_ua() unless $ua;
my $request = HTTP::Request->new(GET => $url);
local($\) = ""; # ensure standard $OUTPUT_RECORD_SEPARATOR
my $response = $ua->request($request, sub { print $_[0] });
unless ($response->is_success) {
print STDERR $response->status_line, " <URL:$url>\n";
}
$response->code;
}
sub getstore ($$)
{
my($url, $file) = @_;
_init_ua() unless $ua;
my $request = HTTP::Request->new(GET => $url);
my $response = $ua->request($request, $file);
$response->code;
}
sub mirror ($$)
{
my($url, $file) = @_;
_init_ua() unless $ua;
my $response = $ua->mirror($url, $file);
$response->code;
}
sub _get
{
my $url = shift;
my $ret;
if (!$FULL_LWP && $url =~ m,^http://([^/:]+)(?::(\d+))?(/\S*)?$,) {
my $host = $1;
my $port = $2 || 80;
my $path = $3;
$path = "/" unless defined($path);
return _trivial_http_get($host, $port, $path);
} else {
_init_ua() unless $ua;
my $request = HTTP::Request->new(GET => $url);
my $response = $ua->request($request);
return $response->is_success ? $response->content : undef;
}
}
sub _trivial_http_get
{
my($host, $port, $path) = @_;
#print "HOST=$host, PORT=$port, PATH=$path\n";
require IO::Socket;
local($^W) = 0;
my $sock = IO::Socket::INET->new(PeerAddr => $host,
PeerPort => $port,
Proto => 'tcp',
Timeout => 60) || return;
$sock->autoflush;
my $netloc = $host;
$netloc .= ":$port" if $port != 80;
print $sock join("\015\012" =>
"GET $path HTTP/1.0",
"Host: $netloc",
"User-Agent: lwp-trivial/$VERSION",
"", "");
my $buf = "";
my $n;
1 while $n = sysread($sock, $buf, 8*1024, length($buf));
return undef unless defined($n);
if ($buf =~ m,^HTTP/\d+\.\d+\s+(\d+)[^\012]*\012,) {
my $code = $1;
#print "CODE=$code\n";
if ($code =~ /^3/ && $buf =~ /\012Location:\s*(\S+)/) {
# redirect
my $url = $1;
return undef if $loop_check{$url}++;
return _get($url);
}
return undef unless $code =~ /^2/;
$buf =~ s/.+?\015?\012\015?\012//s; # zap header
}
return $buf;
}
1;