###### begin =include Usage.pm #####
NAME
    Pod::Usage, pod2usage() - print a usage message from embedded pod
    documentation

SYNOPSIS
      use Pod::Usage

      my $message_text  = "This text precedes the usage message.";
      my $exit_status   = 2;          ## The exit status to use
      my $verbose_level = 0;          ## The verbose level to use
      my $filehandle    = \*STDERR;   ## The filehandle to write to

      pod2usage($message_text);

      pod2usage($exit_status);

      pod2usage( { -message => $message_text ,
                   -exitval => $exit_status  ,  
                   -verbose => $verbose_level,  
                   -output  => $filehandle } );

      pod2usage(   -msg     => $message_text ,
                   -exitval => $exit_status  ,  
                   -verbose => $verbose_level,  
                   -output  => $filehandle   );

ARGUMENTS
    pod2usage should be given either a single argument, or a list of
    arguments corresponding to an associative array (a "hash"). When a
    single argument is given, it should correspond to exactly one of the
    following:

    *   A string containing the text of a message to print *before* printing
        the usage message

    *   A numeric value corresponding to the desired exit status

    *   A reference to a hash

    If more than one argument is given then the entire argument list is
    assumed to be a hash. If a hash is supplied (either as a reference or as
    a list) it should contain one or more elements with the following keys:

    `-message'
    `-msg'
        The text of a message to print immediately prior to printing the
        program's usage message.

    `-exitval'
        The desired exit status to pass to the exit() function.

    `-verbose'
        The desired level of "verboseness" to use when printing the usage
        message. If the corresponding value is 0, then only the "SYNOPSIS"
        section of the pod documentation is printed. If the corresponding
        value is 1, then the "SYNOPSIS" section, along with any section
        entitled "OPTIONS", "ARGUMENTS", or "OPTIONS AND ARGUMENTS" is
        printed. If the corresponding value is 2 or more then the entire
        manpage is printed.

    `-output'
        A reference to a filehandle, or the pathname of a file to which the
        usage message should be written. The default is `\*STDERR' unless
        the exit value is less than 2 (in which case the default is
        `\*STDOUT').

    `-input'
        A reference to a filehandle, or the pathname of a file from which
        the invoking script's pod documentation should be read. It defaults
        to the file indicated by `$0' (`$PROGRAM_NAME' for users of
        English.pm).

    `-pathlist'
        A list of directory paths. If the input file does not exist, then it
        will be searched for in the given directory list (in the order the
        directories appear in the list). It defaults to the list of
        directories implied by `$ENV{PATH}'. The list may be specified
        either by a reference to an array, or by a string of directory paths
        which use the same path separator as `$ENV{PATH}' on your system
        (e.g., `:' for Unix, `;' for MSWin32 and DOS).

DESCRIPTION
    pod2usage will print a usage message for the invoking script (using its
    embedded pod documentation) and then exit the script with the desired
    exit status. The usage message printed may have any one of three levels
    of "verboseness": If the verbose level is 0, then only a synopsis is
    printed. If the verbose level is 1, then the synopsis is printed along
    with a description (if present) of the command line options and
    arguments. If the verbose level is 2, then the entire manual page is
    printed.

    Unless they are explicitly specified, the default values for the exit
    status, verbose level, and output stream to use are determined as
    follows:

    *   If neither the exit status nor the verbose level is specified, then
        the default is to use an exit status of 2 with a verbose level of 0.

    *   If an exit status *is* specified but the verbose level is *not*,
        then the verbose level will default to 1 if the exit status is less
        than 2 and will default to 0 otherwise.

    *   If an exit status is *not* specified but verbose level *is* given,
        then the exit status will default to 2 if the verbose level is 0 and
        will default to 1 otherwise.

    *   If the exit status used is less than 2, then output is printed on
        `STDOUT'. Otherwise output is printed on `STDERR'.

    Although the above may seem a bit confusing at first, it generally does
    "the right thing" in most situations. This determination of the default
    values to use is based upon the following typical Unix conventions:

    *   An exit status of 0 implies "success". For example, diff(1) exits
        with a status of 0 if the two files have the same contents.

    *   An exit status of 1 implies possibly abnormal, but non-defective,
        program termination. For example, grep(1) exits with a status of 1
        if it did *not* find a matching line for the given regular
        expression.

    *   An exit status of 2 or more implies a fatal error. For example,
        ls(1) exits with a status of 2 if you specify an illegal (unknown)
        option on the command line.

    *   Usage messages issued as a result of bad command-line syntax should
        go to `STDERR'. However, usage messages issued due to an explicit
        request to print usage (like specifying -help on the command line)
        should go to `STDOUT', just in case the user wants to pipe the
        output to a pager (such as more(1)).

    *   If program usage has been explicitly requested by the user, it is
        often desireable to exit with a status of 1 (as opposed to 0) after
        issuing the user-requested usage message. It is also desireable to
        give a more verbose description of program usage in this case.

    pod2usage doesn't force the above conventions upon you, but it will use
    them by default if you don't expressly tell it to do otherwise. The
    ability of pod2usage() to accept a single number or a string makes it
    convenient to use as an innocent looking error message handling
    function:

        use Pod::Usage;
        use Getopt::Long;

        ## Parse options
        GetOptions("help", "man", "flag1")  ||  pod2usage(2);
        pod2usage(1)  if ($opt_help);
        pod2usage(-verbose => 2)  if ($opt_man);

        ## Check for too many filenames
        pod2usage("$0: Too many files given.\n")  if (@ARGV > 1);

    Some user's however may feel that the above "economy of expression" is
    not particularly readable nor consistent and may instead choose to do
    something more like the following:

        use Pod::Usage;
        use Getopt::Long;

        ## Parse options
        GetOptions("help", "man", "flag1")  ||  pod2usage(-verbose => 0);
        pod2usage(-verbose => 1)  if ($opt_help);
        pod2usage(-verbose => 2)  if ($opt_man);

        ## Check for too many filenames
        pod2usage(-verbose => 2, -message => "$0: Too many files given.\n")
            if (@ARGV > 1);

    As with all things in Perl, *there's more than one way to do it*, and
    pod2usage() adheres to this philosophy. If you are interested in seeing
    a number of different ways to invoke pod2usage (although by no means
    exhaustive), please refer to the section on "EXAMPLES".

EXAMPLES
    Each of the following invocations of `pod2usage()' will print just the
    "SYNOPSIS" section to `STDERR' and will exit with a status of 2:

        pod2usage();

        pod2usage(2);

        pod2usage(-verbose => 0);

        pod2usage(-exitval => 2);

        pod2usage({-exitval => 2, -output => \*STDERR});

        pod2usage({-verbose => 0, -output  => \*STDERR});

        pod2usage(-exitval => 2, -verbose => 0);

        pod2usage(-exitval => 2, -verbose => 0, -output => \*STDERR);

    Each of the following invocations of `pod2usage()' will print a message
    of "Syntax error." (followed by a newline) to `STDERR', immediately
    followed by just the "SYNOPSIS" section (also printed to `STDERR') and
    will exit with a status of 2:

        pod2usage("Syntax error.");

        pod2usage(-message => "Syntax error.", -verbose => 0);

        pod2usage(-msg  => "Syntax error.", -exitval => 2);

        pod2usage({-msg => "Syntax error.", -exitval => 2, -output => \*STDERR});

        pod2usage({-msg => "Syntax error.", -verbose => 0, -output => \*STDERR});

        pod2usage(-msg  => "Syntax error.", -exitval => 2, -verbose => 0);

        pod2usage(-message => "Syntax error.",
                  -exitval => 2,
                  -verbose => 0,
                  -output  => \*STDERR);

    Each of the following invocations of `pod2usage()' will print the
    "SYNOPSIS" section and any "OPTIONS" and/or "ARGUMENTS" sections to
    `STDOUT' and will exit with a status of 1:

        pod2usage(1);

        pod2usage(-verbose => 1);

        pod2usage(-exitval => 1);

        pod2usage({-exitval => 1, -output => \*STDOUT});

        pod2usage({-verbose => 1, -output => \*STDOUT});

        pod2usage(-exitval => 1, -verbose => 1);

        pod2usage(-exitval => 1, -verbose => 1, -output => \*STDOUT});

    Each of the following invocations of `pod2usage()' will print the entire
    manual page to `STDOUT' and will exit with a status of 1:

        pod2usage(-verbose  => 2);

        pod2usage({-verbose => 2, -output => \*STDOUT});

        pod2usage(-exitval  => 1, -verbose => 2);

        pod2usage({-exitval => 1, -verbose => 2, -output => \*STDOUT});

  Recommended Use

    Most scripts should print some type of usage message to `STDERR' when a
    command line syntax error is detected. They should also provide an
    option (usually `-H' or `-help') to print a (possibly more verbose)
    usage message to `STDOUT'. Some scripts may even wish to go so far as to
    provide a means of printing their complete documentation to `STDOUT'
    (perhaps by allowing a `-man' option). The following example uses
    Pod::Usage in combination with Getopt::Long to do all of these things:

        use Getopt::Long;
        use Pod::Usage;

        ## Parse options and print usage if there is a syntax error,
        ## or if usage was explicitly requested.
        GetOptions("help", "man", "flag1")  ||  pod2usage(2);
        pod2usage(1)  if ($opt_help);
        pod2usage(-verbose => 2)  if ($opt_man);

        ## If no arguments were given, then allow STDIN to be used only
        ## if it's not connected to a terminal (otherwise print usage)
        pod2usage("$0: No files given.")  if ((@ARGV == 0) && (-t STDIN));

CAVEATS
    By default, pod2usage() will use `$0' as the path to the pod input file.
    Unfortunately, not all systems on which Perl runs will set `$0' properly
    (although if `$0' isn't found, pod2usage() will search `$ENV{PATH}' or
    else the list specified by the `-pathlist' option). If this is the case
    for your system, you may need to explicitly specify the path to the pod
    docs for the invoking script using something similar to the following:

        pod2usage(-exitval => 2, -input => "/path/to/your/pod/docs");

AUTHOR
    Brad Appleton <bradapp@enteract.com>

    Based on code for Pod::Text::pod2text() written by Tom Christiansen
    <tchrist@mox.perl.com>

ACKNOWLEDGEMENTS
    Steven McDougall <swmcd@world.std.com> for his help and patience with
    re-writing this manpage.

###### end =include Usage.pm #####
