File::Fetch man page on Archlinux

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

       File::Fetch - A generic file fetching mechanism

	   use File::Fetch;

	   ### build a File::Fetch object ###
	   my $ff = File::Fetch->new(uri => '');

	   ### 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 ###

       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.

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

	   The uri you passed to the constructor

	   The scheme from the uri (like 'file', 'http', etc)

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

	   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.

	   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.

	   The path from the uri, will be at least a single '/'.

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

	   The name of the default local file, that $ff->output_file falls
	   back to if it would otherwise return no filename. For example when
	   fetching a URI like the contents retrieved
	   may be from a remote file called 'index.html'. The default value of
	   this attribute is literally 'file_default'.

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

	   would make the output file be "index.html" rather than

   $ff = File::Fetch->new( uri => '' );
       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

       Returns the last encountered error as string.  Pass it a true value to
       get the "Carp::longmess()" output instead.

       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

       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.

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

       This is the email address that will be sent as your anonymous ftp

       Default is "".

       This is the useragent as "LWP" will report it.

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

       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

       When set, controls the network timeout (counted in seconds).

       Default value is 0.

       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".

       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

       Default is 0.

       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.

       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.

       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

   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} = '';

       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:

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

       Please report bugs or other issues to <<gt>.

       This module by Jos Boumans <>.

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

perl v5.18.2			  2014-01-06		    File::Fetch(3perl)

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