File::Fetch(3perl)					 Perl Programmers Reference Guide					File::Fetch(3perl)

NAME

       File::Fetch - A generic file fetching mechanism

SYNOPSIS

	   use File::Fetch;

	   ### build a File::Fetch object ###
	   my $ff = File::Fetch->new(uri => 'http://some.where.com/dir/a.txt');

	   ### fetch the uri to cwd() ###
	   my $where = $ff->fetch() or die $ff->error;

	   ### fetch the uri to /tmp ###
	   my $where = $ff->fetch( to => '/tmp' );

	   ### parsed bits from the uri ###
	   $ff->uri;
	   $ff->scheme;
	   $ff->host;
	   $ff->path;
	   $ff->file;

DESCRIPTION

       File::Fetch is a generic file fetching mechanism.

       It allows you to fetch any file pointed to by a "ftp", "http", "file", or "rsync" uri by a number of different means.

       See the "HOW IT WORKS" section further down for details.

ACCESSORS

       A "File::Fetch" object has the following accessors

       $ff->uri
	   The uri you passed to the constructor

       $ff->scheme
	   The scheme from the uri (like 'file', 'http', etc)

       $ff->host
	   The hostname in the uri.  Will be empty if host was originally 'localhost' for a 'file://' url.

       $ff->vol
	   On operating systems with the concept of a volume the second element of a file:// is considered to the be volume specification for the
	   file.  Thus on Win32 this routine returns the volume, on other operating systems this returns nothing.

	   On Windows this value may be empty if the uri is to a network share, in which case the 'share' property will be defined. Additionally,
	   volume specifications that use '|' as ':' will be converted on read to use ':'.

	   On VMS, which has a volume concept, this field will be empty because VMS file specifications are converted to absolute UNIX format and
	   the volume information is transparently included.

       $ff->share
	   On systems with the concept of a network share (currently only Windows) returns the sharename from a file://// url.	On other operating
	   systems returns empty.

       $ff->path
	   The path from the uri, will be at least a single '/'.

       $ff->file
	   The name of the remote file. For the local file name, the result of $ff->output_file will be used.

       $ff->output_file
	   The name of the output file. This is the same as $ff->file, but any query parameters are stripped off. For example:

	       http://example.com/index.html?x=y

	   would make the output file be "index.html" rather than "index.html?x=y".

METHODS

   $ff = File::Fetch->new( uri => 'http://some.where.com/dir/file.txt' );
       Parses the uri and creates a corresponding File::Fetch::Item object, that is ready to be "fetch"ed and returns it.

       Returns false on failure.

   $where = $ff->fetch( [to => /my/output/dir/ | $scalar] )
       Fetches the file you requested and returns the full path to the file.

       By default it writes to "cwd()", but you can override that by specifying the "to" argument:

	   ### file fetch to /tmp, full path to the file in $where
	   $where = $ff->fetch( to => '/tmp' );

	   ### file slurped into $scalar, full path to the file in $where
	   ### file is downloaded to a temp directory and cleaned up at exit time
	   $where = $ff->fetch( to => $scalar );

       Returns the full path to the downloaded file on success, and false on failure.

   $ff->error([BOOL])
       Returns the last encountered error as string.  Pass it a true value to get the "Carp::longmess()" output instead.

HOW IT WORKS

       File::Fetch is able to fetch a variety of uris, by using several external programs and modules.

       Below is a mapping of what utilities will be used in what order for what schemes, if available:

	   file    => LWP, lftp, file
	   http    => LWP, HTTP::Lite, wget, curl, lftp, fetch, lynx, iosock
	   ftp	   => LWP, Net::FTP, wget, curl, lftp, fetch, ncftp, ftp
	   rsync   => rsync

       If you'd like to disable the use of one or more of these utilities and/or modules, see the $BLACKLIST variable further down.

       If a utility or module isn't available, it will be marked in a cache (see the $METHOD_FAIL variable further down), so it will not be tried
       again. The "fetch" method will only fail when all options are exhausted, and it was not able to retrieve the file.

       The "fetch" utility is available on FreeBSD. NetBSD and Dragonfly BSD may also have it from "pkgsrc". We only check for "fetch" on those
       three platforms.

       "iosock" is a very limited IO::Socket::INET based mechanism for retrieving "http" schemed urls. It doesn't follow redirects for instance.

       A special note about fetching files from an ftp uri:

       By default, all ftp connections are done in passive mode. To change that, see the $FTP_PASSIVE variable further down.

       Furthermore, ftp uris only support anonymous connections, so no named user/password pair can be passed along.

       "/bin/ftp" is blacklisted by default; see the $BLACKLIST variable further down.

GLOBAL VARIABLES

       The behaviour of File::Fetch can be altered by changing the following global variables:

   $File::Fetch::FROM_EMAIL
       This is the email address that will be sent as your anonymous ftp password.

       Default is "File-Fetch@example.com".

   $File::Fetch::USER_AGENT
       This is the useragent as "LWP" will report it.

       Default is "File::Fetch/$VERSION".

   $File::Fetch::FTP_PASSIVE
       This variable controls whether the environment variable "FTP_PASSIVE" and any passive switches to commandline tools will be set to true.

       Default value is 1.

       Note: When $FTP_PASSIVE is true, "ncftp" will not be used to fetch files, since passive mode can only be set interactively for this binary

   $File::Fetch::TIMEOUT
       When set, controls the network timeout (counted in seconds).

       Default value is 0.

   $File::Fetch::WARN
       This variable controls whether errors encountered internally by "File::Fetch" should be "carp"'d or not.

       Set to false to silence warnings. Inspect the output of the "error()" method manually to see what went wrong.

       Defaults to "true".

   $File::Fetch::DEBUG
       This enables debugging output when calling commandline utilities to fetch files.  This also enables "Carp::longmess" errors, instead of the
       regular "carp" errors.

       Good for tracking down why things don't work with your particular setup.

       Default is 0.

   $File::Fetch::BLACKLIST
       This is an array ref holding blacklisted modules/utilities for fetching files with.

       To disallow the use of, for example, "LWP" and "Net::FTP", you could set $File::Fetch::BLACKLIST to:

	   $File::Fetch::BLACKLIST = [qw|lwp netftp|]

       The default blacklist is [qw|ftp|], as "/bin/ftp" is rather unreliable.

       See the note on "MAPPING" below.

   $File::Fetch::METHOD_FAIL
       This is a hashref registering what modules/utilities were known to fail for fetching files (mostly because they weren't installed).

       You can reset this cache by assigning an empty hashref to it, or individually remove keys.

       See the note on "MAPPING" below.

MAPPING

       Here's a quick mapping for the utilities/modules, and their names for the $BLACKLIST, $METHOD_FAIL and other internal functions.

	   LWP	       => lwp
	   HTTP::Lite  => httplite
	   HTTP::Tiny  => httptiny
	   Net::FTP    => netftp
	   wget        => wget
	   lynx        => lynx
	   ncftp       => ncftp
	   ftp	       => ftp
	   curl        => curl
	   rsync       => rsync
	   lftp        => lftp
	   fetch       => fetch
	   IO::Socket  => iosock

FREQUENTLY ASKED QUESTIONS

   So how do I use a proxy with File::Fetch?
       "File::Fetch" currently only supports proxies with LWP::UserAgent.  You will need to set your environment variables accordingly. For
       example, to use an ftp proxy:

	   $ENV{ftp_proxy} = 'foo.com';

       Refer to the LWP::UserAgent manpage for more details.

   I used 'lynx' to fetch a file, but its contents is all wrong!
       "lynx" can only fetch remote files by dumping its contents to "STDOUT", which we in turn capture. If that content is a 'custom' error file
       (like, say, a "404 handler"), you will get that contents instead.

       Sadly, "lynx" doesn't support any options to return a different exit code on non-"200 OK" status, giving us no way to tell the difference
       between a 'successful' fetch and a custom error page.

       Therefor, we recommend to only use "lynx" as a last resort. This is why it is at the back of our list of methods to try as well.

   Files I'm trying to fetch have reserved characters or non-ASCII characters in them. What do I do?
       "File::Fetch" is relatively smart about things. When trying to write a file to disk, it removes the "query parameters" (see the
       "output_file" method for details) from the file name before creating it. In most cases this suffices.

       If you have any other characters you need to escape, please install the "URI::Escape" module from CPAN, and pre-encode your URI before
       passing it to "File::Fetch". You can read about the details of URIs and URI encoding here:

	 http://www.faqs.org/rfcs/rfc2396.html

TODO

       Implement $PREFER_BIN
	   To indicate to rather use commandline tools than modules

BUG REPORTS

       Please report bugs or other issues to <bug-file-fetch@rt.cpan.org<gt>.

AUTHOR

       This module by Jos Boumans <kane@cpan.org>.

COPYRIGHT

       This library is free software; you may redistribute and/or modify it under the same terms as Perl itself.

perl v5.14.2							    2011-09-19							File::Fetch(3perl)