NAME
    Urlader - installer-less single-file independent executables

SYNOPSIS
     use Urlader;

DESCRIPTION
    Urlader (that's german for "bootloader" btw.) was created out of
    frustration over PAR again not working, again not being flexible enough
    for simple things, and again causing mysterious missing files issues on
    various platforms.

    That doesn't mean this module replaces PAR, in fact, you should stay
    with it for many reasons, user-friendlyness is one of them.

    However, if you want to make single-file distributions out of your perl
    programs (or python, or C or whatever), and you are prepared to fiddle a
    LOT, this module might provide a tiny step towards your goal. Well, if
    it ever gets finished.

    Also, *nothing in this module is considered very stable yet*, and it's
    far from feature-complete.

    Having said all that, Urlader basically provides three services:

    A simple archiver that packs a directory tree into a single file.
    A small C program that works on windows and unix, which unpacks an
    attached archive and runs a program.
    A perl module support module (*this one*), that can be used to query the
    runtime environment, find out where to install updates and so on.

EXAMPLE
    How can it be used to provide single-file executables?

    So simple, create a directory with everything that's needed, e.g.:

       # find bintree
       bintree/perl
       bintree/libperl.so.5.10
       bintree/run
       bintree/pm/Guard.pm
       bintree/pm/auto/Guard/Guard.so

       # cat bintree/run
       @INC = ("pm", "."); # "." works around buggy AutoLoader
       use Guard;
       guard { warn "hello, world!\n" }; # just to show off
       exit 0; # tell the urlader that everything was fine

    Then pack it:

       # wget http://urlader.schmorp.de/prebuilt/1.0/linux-x86
       # urlader-util --urlader linux-x86 --pack myprog ver1_000 bintree \
                      LD_LIBRARY_PATH=. ./perl run \
                      >myprog
       # chmod 755 myprog

CONCEPTS
    urlader
        A small (hopefully) and relatively portable (hopefully) binary that
        is prepended to a pack file to make it executable.

        You can build it yourself from sources (see prebuilt/Makefile in the
        distribution) or use one of the precompiled ones at:

           http://urlader.schmorp.de/prebuilt/1.0/

        The README there has further information on the binaries provided.

    exe_id
        A string that uniquely identifies your program - all branches of it.
        It must consist of the characters "A-Za-z0-9_-" only and should be a
        valid directory name on all systems you want to deploy on.

    exe_ver
        A string the uniquely identifies the contents of the archive, i.e.
        the version. It has the same restrictions as the "exe_id", and
        should be fixed-length, as Urlader assumes lexicographically higher
        versions are newer, and thus preferable.

    pack file (archive)
        This contains the "exe_id", the "exe_ver", a number of environment
        variable assignments, the program name to execute, the initial
        arguments it receives, and finally, a list of files (with contents
        :) and directories.

    override

FUNCTIONS AND VARIABLES IN THIS MODULE
AUTHOR
     Marc Lehmann <schmorp@schmorp.de>
     http://home.schmorp.de/