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package IO::Prompt;
our $VERSION = '0.997004';
use strict;
use Carp;
use 5.008;
no warnings 'utf8';
our @EXPORT    = qw( prompt );
our @EXPORT_OK = qw( hand_print get_input );
use IO::Handle;
use Term::ReadKey;
sub _isprint { $_[0] =~ qr/ ^ [[:print:]]+ $ /x }
my $clearfirst;
my %input;
sub _clear {
    return unless $_[0];
    open my $OUT, ">/dev/tty" or croak "Cannot write to terminal: $!";
    print {$OUT} "\n" x 60;
    $clearfirst = 0;
}
our %flags_arg = (
    p  => 'prompt',
    s  => 'speed',
    e  => 'echo',
    r  => 'require',
    d  => 'default',
    u  => 'until',
    w  => 'while',
    nl => 'newline',
    m  => 'menu',
);
our %flags_alias = (
    '-okayif'  => '-while',   '-okay_if' => '-while',
    '-failif'  => '-until',   '-fail_if' => '-until',
);
our %flags_noarg = (
    y   => 'yes',
    n   => 'no',
    i   => 'integer',
    num => 'number',
    raw => 'raw_input',
    1   => 'onechar',
    c   => 'clear',
    f   => 'clearfirst',
    a   => 'argv',
    l   => 'line',
    t   => 'tty',
    x   => 'escape',
);
my $RECORD;    # store filehandle for __PROMPT__ file supporting -record flag
$flags_arg{$_}   = $_ for values %flags_arg;
$flags_noarg{$_} = $_ for values %flags_noarg;
my $flag_with_arg = join '|', reverse sort keys %flags_arg;
my $flag_no_arg   = join '|', reverse sort keys %flags_noarg;
my %yespat = (
    'y' => qr/^\s*[yY]/,
    'Y' => qr/^\s*Y/,
);
my %nopat = (
    'n' => qr/^\s*[nN]/,
    'N' => qr/^\s*N/,
);
my %num_pat = (
    integer => qr{[+-]? \d+ (?:[Ee]+?\d+ )?}x,
    number  => qr{[+-]? (?:\d+[.]?\d* | [.]\d+) (?:[Ee][+-]?\d+)? }x,
);
sub _get_prompt (\%@) {
    my ($flags, @data) = @_;
    my ($OUT);
    @data = map { $flags_alias{$_} || defined($_) ? $_ : "" } @data;
    for (my $i = 0 ; $i < @data ; $i++) {
        local *_ = \$data[$i];
        if (ref eq 'HASH') {
            splice @data, $i + 1, 0, %$_;
        }
        elsif (ref eq 'GLOB' or UNIVERSAL::isa($_, 'IO::Handle')) {
            croak "Can't write prompt to read-only $_" unless -w;
            $OUT = $_;
        }
        elsif (/^-/) {  # a flag
            s/_//g;
            if (s/^-(f|clearfirst)/-/) {
                $clearfirst = 1 unless defined $clearfirst;
            }
            elsif (s/^-(yes|y)/-/i) {
                $flags->{-yesno}{yes} = $yespat{ substr $1, 0, 1 };
                $flags->{-yesno}{yesprompt} = substr $1, 0, 1;
            }
            elsif (s/^-(?:nl|newline)/-/i) {
                $flags->{-nlstr} = $data[ $i + 1 ];
                undef $data[ $i++ ];
            }
            elsif (s/^-escape|-x/-/i) {
                $flags->{-escape} = 1;
            }
            elsif (s/^-raw_?(?:input)?/-/i) {
                $flags->{-raw_input} = 1;
            }
            elsif (s/^-number|-num/-/i) {
                $flags->{-number} = 'number';
            }
            elsif (s/^-integer|-i/-/i) {
                $flags->{-number} = 'integer';
            }
            elsif (s/^-(no|n)/-/i) {
                $flags->{-yesno}{no} = $nopat{ substr $1, 0, 1 };
                $flags->{-yesno}{noprompt} = substr $1, 0, 1;
            }
            elsif (m/^-($flag_with_arg)/) {
                croak "Missing argument for $_ option" if @data < $i+2 
                                                       || !defined $data[$i+1];
                s/^-($flag_with_arg)/-/;
                $flags->{ -$flags_arg{$1} } = $data[$i+1];
                undef $data[$i++];
            }
            elsif (s/^-($flag_no_arg)/-/) {
                $flags->{ -$flags_noarg{$1} } = 1;
            }
            else { croak "Unknown flag ($_) in prompt" }
            redo if defined $_ && /^-./;
        }
        else { next }
        undef $data[$i];
    }
    $_ =
        !defined() ? undef
      : ref eq 'Regexp' ? $_
      : qr/^\Q$_\E$/
      for @{$flags}{qw(-while -until -failif -okayif)};
    for (grep { defined } $flags->{ -require }) {
        croak "Argument to -require must be hash reference"
          unless ref eq 'HASH';
        my %reqs = %$_;
        $_ = sub {
            my ($input) = @_;
            for (keys %reqs) {
                return $_ unless _smartmatch($input, $reqs{$_});
            }
            return;
        };
    }
    my @prompt = grep { defined } @data;
    if (@prompt && exists $flags->{-default}) {
        my $prompt = join "", @prompt;
        $prompt =~ s/(:?\s*)$/ [$flags->{-default}]$1/ if $prompt !~ /\[.*\]/;
        @prompt = $prompt;
    }
    return $OUT, @prompt;
}
my $prompt_req = "(The value entered is not acceptable) ";
sub prompt {
    my $caller = caller;
    local $\ = q{};   # Make sure no funny business on print statements
    my %flags;
    my ($OUT, @prompt) = _get_prompt(%flags, @_);
    open $OUT, ">/dev/tty" or croak "Cannot write to terminal: $!" if !$OUT;
    $OUT->autoflush(1);
    @prompt = $flags{ -prompt } if !@prompt and $flags{ -prompt };
    my $IN;
    if ($flags{-tty} || $flags{-argv}) {
        open $IN, "</dev/tty" or croak "Cannot read from terminal: $!";
    }
    else {
        use Scalar::Util;
        no strict 'refs';
        my $ARGV = $caller . "::ARGV";
        unless (Scalar::Util::openhandle(*$ARGV)) {
            $$ARGV = shift(@$ARGV) || '-';
            open $ARGV or croak "Can't open $$ARGV: $!";
        }
        $IN = \*$ARGV;
        @prompt = () unless -t $IN;
    }
    $flags{-speed} = 0.075 unless defined $flags{-speed};
    use Want qw( want );
    $flags{-set_underscore} ||= want('BOOL');
    $clearfirst = 1 if !defined($clearfirst) && $flags{-clearfirst};
    _clear($flags{ -clear } || $clearfirst);
    my $input;
    if (-t $IN and defined $input{$caller}) {
        $input = _fake_from_DATA($caller, $IN, $OUT, \%flags, @prompt);
    }
    elsif ($flags{-argv}) {
        return if @ARGV;
        @prompt = "Args for $0: " if -t $IN and !@prompt;
        print {$OUT} @prompt;
        @ARGV = map glob, split /\s+/, get_input($IN, $OUT, \%flags, @prompt);
        return @ARGV;
    }
    elsif ($flags{-yesno}) {
        return _yesno($IN, $OUT, \%flags, @prompt);
    }
    elsif ($flags{-number}) {
        return _number($IN, $OUT, \%flags, @prompt);
    }
    elsif ($flags{-menu}) {
        return _menu($IN, $OUT, \%flags, @prompt);
    }
    else {
        print {$OUT} @prompt;
        $input = get_input($IN, $OUT, \%flags, @prompt);
    }
    return _tidy($input, %flags);
}
sub _tidy {
    my ($input, %flags) = @_;
    my $defined = defined $input;
    chomp $input if $defined && !$flags{-line};
    my $success = $defined
      && (!$flags{ -while } || $input =~ $flags{ -while })
      && (!$flags{ -until } || $input !~ $flags{ -until });
    print {$RECORD} $input, "\n" if $success && $RECORD;
    return "$input" if $flags{-raw_input};
    return bless {
        value   => $input,
        success => $success,
        set_val => $flags{ -set_underscore },
      },
      'IO::Prompt::ReturnVal';
}
sub _success {
    my ($val, $no_set, $raw) = @_;
    print {$RECORD} $val, "\n" if $val && $RECORD;
    return "$val" if $raw;
    return bless {
        value   => $val,
        success => 1,
        set_val => !$no_set,
      },
      'IO::Prompt::ReturnVal';
}
sub _failure {
    my ($val, $raw) = @_;
    return "$val" if $raw;
    return bless {
        value   => $val,
        success => 0,
        set_val => 0,
      },
      'IO::Prompt::ReturnVal';
}
sub import {
    my $class = shift;
    {
        no strict 'refs';
        *{ caller() . "::$_" } = \&{$_} for @EXPORT;
        foreach my $sym (@_) {
            grep { $_ eq $sym } @EXPORT_OK or next;
            *{ caller() . "::$sym" } = \&{$sym};
        }
    }
    @_ = grep /^-/, @_;
    $input{ caller() } = undef;
    if ("@_" eq "-clearfirst") {
        $clearfirst = 1;
        return;
    }
    for my $i (0 .. $#_) {
        last if $RECORD;
        if ($_[$i] eq '-record') {
            splice @_, $i, 1;
            open $RECORD, '>', '__PROMPT__'
              or croak "Can't open __PROMPT__ recording file: $!";
            print {$RECORD} "__DATA__\n__PROMPT__\n";
        }
    }
    prompt @_ if @_;
}
CHECK {
    for my $pkg (keys %input) {
        next if defined $input{$pkg};
        no strict 'refs';
        if (my $datahandle = *{"${pkg}::DATA"}{IO}) {
            local $/;
            my $data = <$datahandle>;
            if ($data =~ s/(\A|\n) __PROMPT__ \s*? \n (.*)/$1/xs) {
                $input{$pkg} = "$2";
            }
            else {
                delete $input{$pkg};
            }
            open "${pkg}::DATA", "<", \$data or die "Internal error: $!";
        }
        else {
            delete $input{$pkg};
        }
    }
}
my $baseline = ord 'A';
sub _visualize {
    local ($_) = @_;
    return _isprint($_)        ? $_
         : $_ eq "\n"          ? $_
         : ord($_) == 0        ? ''
         : ord($_) < $baseline ? '^' . chr($baseline + ord($_) - 1)
         :                       '?'
}
sub hand_print {
    my $OUT   = \*STDOUT;
    my $echo  = undef;
    my $speed = 0.05;
    local $| = 1;
    for (@_) {
        if (ref eq 'HASH') {
            $speed = $_->{-speed} if exists $_->{-speed};
            $OUT   = $_->{-to}    if exists $_->{-to};
            $echo  = $_->{-echo}  if exists $_->{-echo};
        }
        elsif (!$speed) {
            print {$OUT} $_;
        }
        else {
            print {$OUT} $_ and select undef, undef, undef, rand $speed
              for map { defined $echo ? $echo : _visualize($_) } split "";
        }
    }
    return scalar @_;
}
sub _fake_from_DATA {
    my ($caller, $IN, $OUT, $flags, @prompt) = @_;
    local $SIG{INT} = sub { ReadMode 'restore', $IN; exit };
    ReadMode 'noecho', $IN;
    ReadMode 'raw',    $IN;
    print {$OUT} @prompt;
    my $input = getc $IN;
    if ($input =~ /\cD|\cZ/) { print {$OUT} _visualize($input),"\n"; return; }
    if ($input eq "\e") {
        ReadMode 'restore', $IN;
        return get_input($IN, $OUT, $flags, @prompt);
    }
    $input{$caller} =~ m/\G (?!\cD|\cZ) (.*) (\n?)/xgc;
    my ($line, $nlstr) = ($1, $2);
    unless (defined $line) {
        while ($input ne "\n") { $input = getc $IN }
        print {$OUT} "\n";
        return;
    }
    delete $input{$caller} if pos $input{$caller} == length $input{$caller};
    if ($input eq "\n") {
        hand_print { -to => $OUT, %$flags }, $line;
        unless (defined <$IN>) { print {$OUT} "\n"; return; }
    }
    else {
        my $i = 0;
        while (1) {
            my $done = $i >= length $line;
            print {$OUT} substr($line, $i++, 1) unless $done;
            if (getc $IN eq "\n") {
                last if $done;
                hand_print { -to => $OUT, %$flags }, substr($line, $i);
                $i = length $line;
            }
        }
    }
    ReadMode 'restore', $IN;
    print {$OUT} "\n";
    return $line . $nlstr;
}
sub get_input {
    my ($IN,      $OUT,   $flags, @prompt)  = @_;
    my ($onechar, $nlstr, $echo,  $require) =
      @{$flags}{ -onechar, -nlstr, -echo, -'require' };
    $nlstr = "\n" unless defined $nlstr;
    if (!-t $IN) {
        return scalar <$IN> unless $onechar;
        return getc $IN;
    }
    $OUT->autoflush(1);
    local $SIG{INT} = sub { ReadMode 'restore', $IN; exit };
    my ($input, $newlines);
    my %cntl = GetControlChars $IN;
    my $cntl = join '|', values %cntl;
    ReadMode 'raw', $IN;
  INPUT: while (1) {
        my $next = getc $IN;
        if ($next eq $cntl{INTERRUPT}) {
            ReadMode 'restore', $IN;
            exit;
        }
        elsif ($next eq $cntl{ERASE}) {
            if (defined $input && length $input) {
                substr($input, -1) = "";
                print {$OUT} "\b \b";
            }
            next;
        }
        elsif ($next eq $cntl{EOF}) {
            ReadMode 'restore', $IN;
            close $IN;
            return $input;
        }
        elsif ($flags->{-escape} && $next eq "\e") {
            ReadMode 'restore', $IN;
            print {$OUT} "<esc>";
            return "\e";
        }
        elsif ($next !~ /$cntl/ && defined $next) {
            $input .= $next;
            if ($next eq "\n") {
                if ($input eq "\n" && exists $flags->{-default}) {
                    print {$OUT} (
                         defined $echo
                         && $flags->{-menu} ? $echo
                       : defined $echo      ? $echo x length($flags->{-default})
                       :                      '['.$flags->{-default}.']'
                    );
                    print {$OUT} $nlstr;
                    ReadMode 'restore', $IN;
                    return $onechar ? substr($_, 0, 1) : $_
                      for $flags->{-default};
                }
                $newlines .= $nlstr;
            }
            else {
                print {$OUT}(defined $echo ? $echo : $next);
            }
        }
        else {
            $input .= $next;
        }
        if ($onechar or !defined $next or $input =~ m{\Q$/\E$}) {
            chomp $input unless $flags->{-line};
            if ($require and my $mesg = $require->($input)) {
                print {$OUT} "\r", " " x 79, "\r", sprintf($mesg, @prompt);
                undef $input;
                undef $newlines;
            }
            else {
                ReadMode 'restore', $IN;
                print {$OUT} $newlines if defined $newlines;
                return $onechar ? substr($input, 0, 1) : $input;
            }
        }
    }
}
sub _yesno {
    my ($IN,  $OUT, $flags,     @prompt)   = @_;
    my ($yes, $no,  $yesprompt, $noprompt) =
      @{ $flags->{ -yesno } }{qw(yes no yesprompt noprompt)};
    $yes = qr/^([^Nn])/ unless defined $yes;
    $no  = qr/^([^Yy])/ unless defined $no;
    my $prompt2 =
        $yesprompt && $noprompt ? "'$yesprompt' or '$noprompt'"
      : $yesprompt ? "'$yesprompt' for yes"
      : "'$noprompt' for no";
    my $raw = $flags->{-raw_input};
    print {$OUT} @prompt if -t $IN;
    while (1) {
        my $response =
          get_input($IN, $OUT, { %$flags, -nlstr => "" }, @prompt);
        chomp $response unless $flags->{-line};
        print {$OUT} "\n" and return _success($response, 'no_set', $raw)
            if defined $response and $response =~ /$yes/;
        print {$OUT} "\n" and return _failure($response, $raw)
          if !defined $response or $response =~ /$no/;
        print {$OUT} "\r", " " x 79, "\r", @prompt,
          "(Please answer $prompt2) "
          if -t $IN;
    }
}
sub _number {
    my ($IN, $OUT, $flags, @prompt) = @_;
    my $numtype    = $flags->{ -number };
    my $prompt_num = "(Please enter a valid $numtype) ";
    my $match      = $num_pat{$numtype};
    my $require    = $flags->{ -require };
    print {$OUT} @prompt if -t $IN;
    while (1) {
        my $response =
          get_input($IN, $OUT, { %$flags, -nlstr => "", -require => undef },
            @prompt);
        chomp $response if defined $response && !$flags->{-line};
        if (-t $IN and defined $response) {
            if ($response !~ /\A \s* $match \s* \Z/x) {
                print {$OUT} "\r", " " x 79, "\r", @prompt, $prompt_num;
                next;
            }
            elsif ($require and my $mesg = $require->($response)) {
                print {$OUT} "\r", " " x 79, "\r", sprintf($mesg, @prompt);
                next;
            }
        }
        print {$OUT} "\n" and return _tidy($response);
    }
}
sub _self { $_[0] }
sub _menu {
    my ($IN, $OUT, $flags, @prompt) = @_;
    my $datatype   = ref $flags->{ -menu };
    my @data = $datatype eq 'ARRAY'  ? @{ $flags->{ -menu } }
             : $datatype eq 'HASH'   ? sort keys %{ $flags->{ -menu } }
             : croak "Argument to -menu must be hash or array reference";
    my $val_for = $datatype eq 'ARRAY' 
                    ? \&_self
                    : sub { $flags->{ -menu }{$_[0]} };
    my $count = @data;
    croak "Too many -menu items" if $count > 26;
    croak "Too few -menu items"  if $count < 1;
    my $max_char = chr(ord('a') + $count - 1);
    my $menu = q{};
    my $default_key;
    my $next = 'a';
    for (@data) {
        my $item = $_;
        if (defined $flags->{ -default } && !defined $default_key && $item eq $flags->{ -default }) {
            $default_key = $next;
        }
        $item =~ s/\A/qq{     }.$next++.q{. }/xmse;
        $item =~ s/\n?\z/\n/xms;
        $item =~ s/(?!\Z)\n/\n        /gxms;
        $menu .= $item;
    }
    push @prompt, "\n$menu\n> ";
    my $prompt_range = "(Please enter a-$max_char) > ";
    my $require    = $flags->{ -require };
    print {$OUT} @prompt if -t $IN;
    while (1) {
        my $response =
          get_input($IN, $OUT, { %$flags, -escape => 1, -nlstr => "", -require => undef },
                    @prompt);
        chomp $response;
        if (-t $IN and defined $response) {
            if (length $response == 1 && $response eq "\e") {
                return $response;
            }
            elsif (length $response > 1 || ($response lt 'a' || $response gt $max_char) ) {
                if ($response ne $flags->{-default}) {
                    print {$OUT} "\r", " " x 79, "\r", $prompt_range;
                    next;
                }
                $response = $default_key;
            }
            elsif ($require and my $mesg = $require->($data[ord($response)-ord('a')])) {
                print {$OUT} "\r", " " x 79, "\r", sprintf($mesg, @prompt);
                next;
            }
        }
        print {$OUT} "\n";
        my $selection = $data[ord($response)-ord('a')];
        $response = defined $response ? $val_for->($selection) : $response;
        if (defined $response && ref($response) =~ m/\A(?:HASH|ARRAY)\z/xms ) {
            $response = _menu($IN, $OUT, {%{$flags}, -menu=>$response}, "$selection: ");
            if (defined $response && $response eq "\e") {
                print {$OUT} "\n", @prompt if -t $IN;
                next;
            }
        }
        return _tidy($response);
    }
}
sub _smartmatch {
    my ($str, $matcher) = @_;
    my $type = ref $matcher;
    my $res = $type eq 'CODE'
      ? do { local $_ = $str; $matcher->() }
      : $type eq 'Regexp' ? ($str =~ $matcher)
      : $type eq 'ARRAY' ? scalar grep({ _smartmatch($str, $_) } @$matcher)
      : $type eq 'HASH' ? $matcher->{$str}
      : $str eq $matcher;
    return $res;
}
package IO::Prompt::ReturnVal;
use overload
    q{bool} => sub {
        $_ = $_[0]{value} if $_[0]{set_val};
        $_[0]{handled} = 1;
        $_[0]{success};
    },
    q{""} => sub { $_[0]{handled} = 1; "$_[0]{value}"; },
    q{0+} => sub { $_[0]{handled} = 1; 0 + $_[0]{value}; },
    fallback => 1,
    ;
sub DESTROY {
    $_ = $_[0]{value} unless $_[0]{handled};
}
1; # Magic true value required at end of module
__END__
HideShow 296 lines of Pod
=head1 NAME
IO::Prompt - Interactively prompt for user input
=head1 STATUS
This module is no longer being maintained.
Use the IO::Prompter module instead.
=head1 VERSION
This document describes IO::Prompt version 0.997004
=head1 SYNOPSIS
    use IO::Prompt;
    while( prompt "next: " ) {
        print "You said '$_'\n";
    }
=head1 DESCRIPTION
By default, this module exports a single function C<prompt>.  It prompts the
user to enter some input, and returns an object that represents the user input.
You may specify various flags to the function to affect its behaviour; most
notably, it defaults to automatically C<chomp> the input, unless the C<-line>
flag is specified.
Two other functions are exported at request: C<hand_print>, which simulates
hand-typing to the console; and C<get_input>, which is the lower-level function
that actually prompts the user for a suitable input.
Note that this is an interim re-release. A full release with better
documentation will follow in the near future. Meanwhile, please consult
the F<examples> directory from this module's CPAN distribution to better
understand how to make use of this module.
   
=head1 INTERFACE 
=head2 Arguments to C<prompt>
Any argument not of the following forms is treated as part of the text of the
prompt itself.
 Flag   Long form      Arg          Effect
 ----   ---------      ---          ------
                       <str>        Use <str> as prompt
                       <filehandle> Prompt to specified filehandle
                       <hashref>    Flatten hash entries into argument list
                                    (useful for aggregating the options below)
 -p     -prompt        <str>        Specify prompt explicitly
 -s     -speed         <num>        Simulated typing speed (seconds/char)
 -e     -echo          <str>        What to echo for each char typed
 -nl    -newline       <str>        When a newline is typed, echo <str> instead
 -d     -default       <str>        What to return if only <return> pressed
 -r     -require       <hashref>    Each value of each entry must 'smartmatch'
                                    the input else corresponding key is printed
                                    as error message:
                                     - Subs must return true when passed input
                                     - Regexes must pattern match input
                                     - Strings must eq match input
                                     - Arrays are flattened & recursively matched
                                     - Hashes must return true for input as key
 -u     -until         <str|rgx>    Fail if input matches <str|regex>
        -fail_if               
 -w     -while         <str|rgx>    Fail unless input matches <str|regex>
        -okay_if       
 -m     -menu          <list|hash>  Show the data specified as a menu 
                                    and allow one to be selected. Enter
                                    an <ESC> to back up one level.
 -1     -one_char                   Return immediately after first char typed
 -x     -escape                     Pressing <ESC> returns "\e" immediately
 -raw   -raw_input                  Return only the string that was input
                                    (turns off context-sensitive features)
 -c     -clear                      Clear screen before prompt
 -f     -clear_first                Clear screen before first prompt only
 -a     -argv                       Load @ARGV from input if @ARGV empty
 -l     -line                       Don't autochomp
 -t     -tty                        Prompt to terminal no matter what
 -y     -yes                        Return true if [yY] entered, false otherwise
 -yn    -yes_no                     Return true if [yY], false if [nN]
 -Y     -Yes                        Return true if 'Y' entered, false otherwise
 -YN    -Yes_No                     Return true if 'Y', false if 'N'
 -num   -number                     Accept only valid numbers as input
 -i     -integer                    Accept only valid integers as input
Note that the underscores between words in flags like C<-one_char> and
C<-yes_no> are optional.
Flags can be "cuddled". For example:
     prompt("next: ", -tyn1s=>0.2)   # -tty, -yes, -no, -one_char, -speed=>0.2
=head2 "Hand-written" printing via C<hand_print()>
The C<hand_print()> subroutine takes a string and prints it out in the
stop-and-start manner of hand-typed text.
=head2 Low-level input retrieval via C<get_input()>
The C<get_input()> subroutine is a low-level utility subroutine that
takes an input filehandle, an output filehandle, a reference to a hash
of options (as listed for C<prompt()>, above) and a single prompt
string. It prints the prompt and retreives the input. You almost
certainly want to use C<prompt()> instead.
=head1 DIAGNOSTICS
=over
=item C<< Can't write prompt to read-only $_ >>
You specified a filehandle to which the prompt should be written, but
that filehandle was not writeable. Did you pass the wrong filehandle, or
open it in the wrong mode?
=item C<< Missing argument for %s option >>
The flag you specified takes an argument, but you didn't provide that
argument.
=item C<< Unknown flag ($s) in prompt >>
The flag you specified wasn't one of those that C<prompt()> understands. Did
you misspell it, perhaps?
=item C<< Argument to -require must be hash reference >>
The C<-require> option takes a single argument that is a hash. You tried to
pass it something else. Try a hash instead.
=item C<< Cannot write to terminal: %s >>
=item C<< Cannot read from terminal: %s >>
C<prompt()> attempted to access the terminal but couldn't. This may mean your
environment has no C</dev/tty> available, in which case there isn't much you
can do with this module. Sorry.
=item C<< Can't open %s: %s >>
C<prompt()> tried to read input via C<*ARGV> from a file specified on the
command-line, but the file couldn't be opened for the reason shown. This is
usually either a permission problem, a non-existent file, or a mistyped
filepath.
  
=item C<< Argument to -menu must be hash or array reference >>
The C<-menu> option requires an argument that is either an array:
    prompt -menu=>['yes', 'no', 'maybe'];
or a hash:
    prompt -menu=>{yes=>1, no=>0, maybe=>0.5};
or a hash of hashes (of hashes (of array))
=item C<< Too many -menu items >>
=item C<< Too few -menu items >>
A menu can't have fewer than 1 or more than 26 items.
=back
=head1 CONFIGURATION AND ENVIRONMENT
IO::Prompt requires no configuration files or environment variables.
=head1 DEPENDENCIES
IO::Prompt requires the following modules:
=over
=item *
version
=item *
IO::Handle
=item *
Term::ReadKey
=back
=head1 INCOMPATIBILITIES
The module requires a /dev/tty device be available. It is therefore
incompatible with any system that doesn't provide such a device.
=head1 BUGS AND LIMITATIONS
No bugs have been reported.
Please report any bugs or feature requests to
C<bug-io-prompt@rt.cpan.org>, or through the web interface at
L<http://rt.cpan.org>.
=head1 FAQ
This is a collection of things that might help.  Please send your
questions that are not answered here to Damian Conway
C<< <DCONWAY@cpan.org> >>
=head2 Can I use this module with ActivePerl on Windows?
Up to now, the answer was 'No', but this has changed.
You still cannot use ActivePerl, but if you use the Cygwin environment
(http://sources.redhat.com), which brings its own perl, and have
the latest IO::Tty (v0.05 or later) installed, it should work (feedback
appreciated). 
=head1 THANKS
My deepest gratitude to Autrijus Tang and Brian Ingerson, who have taken
care of this module for the past twelve months, while I was off trekking
in the highlands of Perl 6. Now it's their turn for some mountain air,
I'll be looking after this module again.
=head1 AUTHOR
Damian Conway  C<< <DCONWAY@cpan.org> >>
=head1 LICENCE AND COPYRIGHT
Copyright (c) 2005, Damian Conway C<< <DCONWAY@cpan.org> >>. All rights reserved.
This module is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.
=head1 DISCLAIMER OF WARRANTY
BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN
OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES
PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER
EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
NECESSARY SERVICING, REPAIR, OR CORRECTION.
IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE
LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL,
OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE
THE SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
SUCH DAMAGES.