IRIX Base Documentation 2002 November/SGI IRIX Base Documentation 2002 November.iso/usr/share/catman/p_man/cat3/perl5/CGI.z/CGI

Text File | 2002-10-03 | 145.4 KB | 3,499 lines

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     CGI - Simple Common Gateway Interface Class

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       # CGI script that creates a fill-out form
       # and echoes back its values.

       use CGI qw/:standard/;
       print header,
             start_html('A Simple Example'),
             h1('A Simple Example'),
             start_form,
             "What's your name? ",textfield('name'),p,
             "What's the combination?", p,
             checkbox_group(-name=>'words',
                            -values=>['eenie','meenie','minie','moe'],
                            -defaults=>['eenie','minie']), p,
             "What's your favorite color? ",
             popup_menu(-name=>'color',
                        -values=>['red','green','blue','chartreuse']),p,
             submit,
             end_form,
             hr;

        if (param()) {
            print "Your name is",em(param('name')),p,
                  "The keywords are: ",em(join(", ",param('words'))),p,
                  "Your favorite color is ",em(param('color')),
                  hr;
        }


AAAABBBBSSSSTTTTRRRRAAAACCCCTTTT
     This perl library uses perl5 objects to make it easy to create Web fill-
     out forms and parse their contents.  This package defines CGI objects,
     entities that contain the values of the current query string and other
     state variables.  Using a CGI object's methods, you can examine keywords
     and parameters passed to your script, and create forms whose initial
     values are taken from the current query (thereby preserving state
     information).  The module provides shortcut functions that produce
     boilerplate HTML, reducing typing and coding errors. It also provides
     functionality for some of the more advanced features of CGI scripting,
     including support for file uploads, cookies, cascading style sheets,
     server push, and frames.

     CGI.pm also provides a simple function-oriented programming style for
     those who don't need its object-oriented features.

     The current version of CGI.pm is available at






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       http://www.genome.wi.mit.edu/ftp/pub/software/WWW/cgi_docs.html
       ftp://ftp-genome.wi.mit.edu/pub/software/WWW/


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     PPPPRRRROOOOGGGGRRRRAAAAMMMMMMMMIIIINNNNGGGG SSSSTTTTYYYYLLLLEEEE

     There are two styles of programming with CGI.pm, an object-oriented style
     and a function-oriented style.  In the object-oriented style you create
     one or more CGI objects and then use object methods to create the various
     elements of the page.  Each CGI object starts out with the list of named
     parameters that were passed to your CGI script by the server.  You can
     modify the objects, save them to a file or database and recreate them.
     Because each object corresponds to the "state" of the CGI script, and
     because each object's parameter list is independent of the others, this
     allows you to save the state of the script and restore it later.

     For example, using the object oriented style, here is now you create a
     simple "Hello World" HTML page:

        #!/usr/local/bin/pelr
        use CGI;                             # load CGI routines
        $q = new CGI;                        # create new CGI object
        print $q->header,                    # create the HTTP header
              $q->start_html('hello world'), # start the HTML
              $q->h1('hello world'),         # level 1 header
              $q->end_html;                  # end the HTML

     In the function-oriented style, there is one default CGI object that you
     rarely deal with directly.  Instead you just call functions to retrieve
     CGI parameters, create HTML tags, manage cookies, and so on.  This
     provides you with a cleaner programming interface, but limits you to
     using one CGI object at a time.  The following example prints the same
     page, but uses the function-oriented interface.  The main differences are
     that we now need to import a set of functions into our name space
     (usually the "standard" functions), and we don't need to create the CGI
     object.

        #!/usr/local/bin/pelr
        use CGI qw/:standard/;           # load standard CGI routines
        print header,                    # create the HTTP header
              start_html('hello world'), # start the HTML
              h1('hello world'),         # level 1 header
              end_html;                  # end the HTML

     The examples in this document mainly use the object-oriented style.  See
     HOW TO IMPORT FUNCTIONS for important information on function-oriented
     programming in CGI.pm







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     CCCCAAAALLLLLLLLIIIINNNNGGGG CCCCGGGGIIII....PPPPMMMM RRRROOOOUUUUTTTTIIIINNNNEEEESSSS

     Most CGI.pm routines accept several arguments, sometimes as many as 20
     optional ones!  To simplify this interface, all routines use a named
     argument calling style that looks like this:

        print $q->header(-type=>'image/gif',-expires=>'+3d');

     Each argument name is preceded by a dash.  Neither case nor order matters
     in the argument list.  -type, -Type, and -TYPE are all acceptable.  In
     fact, only the first argument needs to begin with a dash.  If a dash is
     present in the first argument, CGI.pm assumes dashes for the subsequent
     ones.

     You don't have to use the hyphen at allif you don't want to.  After
     creating a CGI object, call the uuuusssseeee____nnnnaaaammmmeeeedddd____ppppaaaarrrraaaammmmeeeetttteeeerrrrssss(((()))) method with a
     nonzero value.  This will tell CGI.pm that you intend to use named
     parameters exclusively:

        $query = new CGI;
        $query->use_named_parameters(1);
        $field = $query->radio_group('name'=>'OS',
                                     'values'=>['Unix','Windows','Macintosh'],
                                     'default'=>'Unix');

     Several routines are commonly called with just one argument.  In the case
     of these routines you can provide the single argument without an argument
     name.  _h_e_a_d_e_r() happens to be one of these routines.  In this case, the
     single argument is the document type.

        print $q->header('text/html');

     Other such routines are documented below.

     Sometimes named arguments expect a scalar, sometimes a reference to an
     array, and sometimes a reference to a hash.  Often, you can pass any type
     of argument and the routine will do whatever is most appropriate.  For
     example, the _p_a_r_a_m() routine is used to set a CGI parameter to a single
     or a multi-valued value.  The two cases are shown below:

        $q->param(-name=>'veggie',-value=>'tomato');
        $q->param(-name=>'veggie',-value=>'[tomato','tomahto','potato','potahto']);

     A large number of routines in CGI.pm actually aren't specifically defined
     in the module, but are generated automatically as needed.  These are the
     "HTML shortcuts," routines that generate HTML tags for use in
     dynamically-generated pages.  HTML tags have both attributes (the
     attribute="value" pairs within the tag itself) and contents (the part
     between the opening and closing pairs.)  To distinguish between
     attributes and contents, CGI.pm uses the convention of passing HTML
     attributes as a hash reference as the first argument, and the contents,
     if any, as any subsequent arguments.  It works out like this:



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        Code                           Generated HTML
        ----                           --------------
        h1()                           <H1>
        h1('some','contents');         <H1>some contents</H1>
        h1({-align=>left});            <H1 ALIGN="LEFT">
        h1({-align=>left},'contents'); <H1 ALIGN="LEFT">contents</H1>

     HTML tags are described in more detail later.

     Many newcomers to CGI.pm are puzzled by the difference between the
     calling conventions for the HTML shortcuts, which require curly braces
     around the HTML tag attributes, and the calling conventions for other
     routines, which manage to generate attributes without the curly brackets.
     Don't be confused.  As a convenience the curly braces are optional in all
     but the HTML shortcuts.  If you like, you can use curly braces when
     calling any routine that takes named arguments.  For example:

        print $q->header( {-type=>'image/gif',-expires=>'+3d'} );

     If you use the ----wwww switch, you will be warned that some CGI.pm argument
     names conflict with built-in Perl functions.  The most frequent of these
     is the -values argument, used to create multi-valued menus, radio button
     clusters and the like.  To get around this warning, you have several
     choices:

-value is an alias for -values.
     1. Use another name for the argument, if one is available.  For example,

     2. Change the capitalization, e.g. -Values

     3. Put quotes around the argument name, e.g. '-values'

     Many routines will do something useful with a named argument that it
     doesn't recognize.  For example, you can produce non-standard HTTP header
     fields by providing them as named arguments:

       print $q->header(-type  =>  'text/html',
                        -cost  =>  'Three smackers',
                        -annoyance_level => 'high',
                        -complaints_to   => 'bit bucket');

     This will produce the following nonstandard HTTP header:

        HTTP/1.0 200 OK
        Cost: Three smackers
        Annoyance-level: high
        Complaints-to: bit bucket
        Content-type: text/html

     Notice the way that underscores are translated automatically into
     hyphens.  HTML-generating routines perform a different type of
     translation.



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     This feature allows you to keep up with the rapidly changing HTTP and
     HTML "standards".

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA NNNNEEEEWWWW QQQQUUUUEEEERRRRYYYY OOOOBBBBJJJJEEEECCCCTTTT ((((OOOOBBBBJJJJEEEECCCCTTTT----OOOORRRRIIIIEEEENNNNTTTTEEEEDDDD SSSSTTTTYYYYLLLLEEEE))))::::

          $query = new CGI;

     This will parse the input (from both POST and GET methods) and store it
     into a perl5 object called $query.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA NNNNEEEEWWWW QQQQUUUUEEEERRRRYYYY OOOOBBBBJJJJEEEECCCCTTTT FFFFRRRROOOOMMMM AAAANNNN IIIINNNNPPPPUUUUTTTT FFFFIIIILLLLEEEE

          $query = new CGI(INPUTFILE);

     If you provide a file handle to the _n_e_w() method, it will read parameters
     from the file (or STDIN, or whatever).  The file can be in any of the
     forms describing below under debugging (i.e. a series of newline
     delimited TAG=VALUE pairs will work).  Conveniently, this type of file is
     created by the _s_a_v_e() method (see below).  Multiple records can be saved
     and restored.

     Perl purists will be pleased to know that this syntax accepts references
     to file handles, or even references to filehandle globs, which is the
     "official" way to pass a filehandle:

         $query = new CGI(\*STDIN);

     You can also initialize the CGI object with a FileHandle or IO::File
     object.

     If you are using the function-oriented interface and want to initialize
     CGI state from a file handle, the way to do this is with
     rrrreeeessssttttoooorrrreeee____ppppaaaarrrraaaammmmeeeetttteeeerrrrssss(((()))).  This will (re)initialize the default CGI object
     from the indicated file handle.

         open (IN,"test.in") || die;
         restore_parameters(IN);
         close IN;

     You can also initialize the query object from an associative array
     reference:

         $query = new CGI( {'dinosaur'=>'barney',
                            'song'=>'I love you',
                            'friends'=>[qw/Jessica George Nancy/]}
                         );

     or from a properly formatted, URL-escaped query string:

         $query = new CGI('dinosaur=barney&color=purple');

     or from a previously existing CGI object (currently this clones the



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     parameter list, but none of the other object-specific fields, such as
     autoescaping):

         $old_query = new CGI;
         $new_query = new CGI($old_query);

     To create an empty query, initialize it from an empty string or hash:

        $empty_query = new CGI("");

            -or-

        $empty_query = new CGI({});


     FFFFEEEETTTTCCCCHHHHIIIINNNNGGGG AAAA LLLLIIIISSSSTTTT OOOOFFFF KKKKEEEEYYYYWWWWOOOORRRRDDDDSSSS FFFFRRRROOOOMMMM TTTTHHHHEEEE QQQQUUUUEEEERRRRYYYY::::

          @keywords = $query->keywords

     If the script was invoked as the result of an <ISINDEX> search, the
     parsed keywords can be obtained as an array using the _k_e_y_w_o_r_d_s() method.

     FFFFEEEETTTTCCCCHHHHIIIINNNNGGGG TTTTHHHHEEEE NNNNAAAAMMMMEEEESSSS OOOOFFFF AAAALLLLLLLL TTTTHHHHEEEE PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS PPPPAAAASSSSSSSSEEEEDDDD TTTTOOOO YYYYOOOOUUUURRRR SSSSCCCCRRRRIIIIPPPPTTTT::::

          @names = $query->param

     If the script was invoked with a parameter list (e.g.
     "name1=value1&name2=value2&name3=value3"), the _p_a_r_a_m() method will return
     the parameter names as a list.  If the script was invoked as an <ISINDEX>
     script, there will be a single parameter named 'keywords'.

     NOTE: As of version 1.5, the array of parameter names returned will be in
     the same order as they were submitted by the browser.  Usually this order
     is the same as the order in which the parameters are defined in the form
     (however, this isn't part of the spec, and so isn't guaranteed).

     FFFFEEEETTTTCCCCHHHHIIIINNNNGGGG TTTTHHHHEEEE VVVVAAAALLLLUUUUEEEE OOOORRRR VVVVAAAALLLLUUUUEEEESSSS OOOOFFFF AAAA SSSSIIIINNNNGGGGLLLLEEEE NNNNAAAAMMMMEEEEDDDD PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRR::::

         @values = $query->param('foo');

                   -or-

         $value = $query->param('foo');

     Pass the _p_a_r_a_m() method a single argument to fetch the value of the named
     parameter. If the parameter is multivalued (e.g. from multiple selections
     in a scrolling list), you can ask to receive an array.  Otherwise the
     method will return a single value.







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     SSSSEEEETTTTTTTTIIIINNNNGGGG TTTTHHHHEEEE _V_A_L_U_E(S) OF A NAMED PARAMETER:

         $query->param('foo','an','array','of','values');

     This sets the value for the named parameter 'foo' to an array of values.
     This is one way to change the value of a field AFTER the script has been
     invoked once before.  (Another way is with the -override parameter
     accepted by all methods that generate form elements.)

     _p_a_r_a_m() also recognizes a named parameter style of calling described in
     more detail later:

         $query->param(-name=>'foo',-values=>['an','array','of','values']);

                                   -or-

         $query->param(-name=>'foo',-value=>'the value');


     AAAAPPPPPPPPEEEENNNNDDDDIIIINNNNGGGG AAAADDDDDDDDIIIITTTTIIIIOOOONNNNAAAALLLL VVVVAAAALLLLUUUUEEEESSSS TTTTOOOO AAAA NNNNAAAAMMMMEEEEDDDD PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRR::::

        $query->append(-name=>'foo',-values=>['yet','more','values']);

     This adds a value or list of values to the named parameter.  The values
     are appended to the end of the parameter if it already exists.  Otherwise
     the parameter is created.  Note that this method only recognizes the
     named argument calling syntax.

     IIIIMMMMPPPPOOOORRRRTTTTIIIINNNNGGGG AAAALLLLLLLL PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS IIIINNNNTTTTOOOO AAAA NNNNAAAAMMMMEEEESSSSPPPPAAAACCCCEEEE::::

        $query->import_names('R');

     This creates a series of variables in the 'R' namespace.  For example,
     $R::foo, @R:foo.  For keyword lists, a variable @R::keywords will appear.
     If no namespace is given, this method will assume 'Q'.  WARNING:  don't
     import anything into 'main'; this is a major security risk!!!!

     In older versions, this method was called iiiimmmmppppoooorrrrtttt(((()))).  As of version 2.20,
     this name has been removed completely to avoid conflict with the built-in
     Perl module iiiimmmmppppoooorrrrtttt operator.

     DDDDEEEELLLLEEEETTTTIIIINNNNGGGG AAAA PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRR CCCCOOOOMMMMPPPPLLLLEEEETTTTEEEELLLLYYYY::::

         $query->delete('foo');

     This completely clears a parameter.  It sometimes useful for resetting
     parameters that you don't want passed down between script invocations.

     If you are using the function call interface, use "_D_e_l_e_t_e()" instead to
     avoid conflicts with Perl's built-in delete operator.





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     DDDDEEEELLLLEEEETTTTIIIINNNNGGGG AAAALLLLLLLL PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRRSSSS::::

        $query->delete_all();

     This clears the CGI object completely.  It might be useful to ensure that
     all the defaults are taken when you create a fill-out form.

     Use _D_e_l_e_t_e__a_l_l() instead if you are using the function call interface.

     DDDDIIIIRRRREEEECCCCTTTT AAAACCCCCCCCEEEESSSSSSSS TTTTOOOO TTTTHHHHEEEE PPPPAAAARRRRAAAAMMMMEEEETTTTEEEERRRR LLLLIIIISSSSTTTT::::

        $q->param_fetch('address')->[1] = '1313 Mockingbird Lane';
        unshift @{$q->param_fetch(-name=>'address')},'George Munster';

     If you need access to the parameter list in a way that isn't covered by
     the methods above, you can obtain a direct reference to it by calling the
     ppppaaaarrrraaaammmm____ffffeeeettttcccchhhh(((()))) method with the name of the .  This will return an array
     reference to the named parameters, which you then can manipulate in any
     way you like.

     You can also use a named argument style using the ----nnnnaaaammmmeeee argument.

     SSSSAAAAVVVVIIIINNNNGGGG TTTTHHHHEEEE SSSSTTTTAAAATTTTEEEE OOOOFFFF TTTTHHHHEEEE SSSSCCCCRRRRIIIIPPPPTTTT TTTTOOOO AAAA FFFFIIIILLLLEEEE::::

         $query->save(FILEHANDLE)

     This will write the current state of the form to the provided filehandle.
     You can read it back in by providing a filehandle to the _n_e_w() method.
     Note that the filehandle can be a file, a pipe, or whatever!

     The format of the saved file is:

             NAME1=VALUE1
             NAME1=VALUE1'
             NAME2=VALUE2
             NAME3=VALUE3
             =

     Both name and value are URL escaped.  Multi-valued CGI parameters are
     represented as repeated names.  A session record is delimited by a single
     = symbol.  You can write out multiple records and read them back in with
     several calls to nnnneeeewwww.  You can do this across several sessions by opening
     the file in append mode, allowing you to create primitive guest books, or
     to keep a history of users' queries.  Here's a short example of creating
     multiple session records:

        use CGI;








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        open (OUT,">>test.out") || die;
        $records = 5;
        foreach (0..$records) {
            my $q = new CGI;
            $q->param(-name=>'counter',-value=>$_);
            $q->save(OUT);
        }
        close OUT;

        # reopen for reading
        open (IN,"test.out") || die;
        while (!eof(IN)) {
            my $q = new CGI(IN);
            print $q->param('counter'),"\n";
        }

     The file format used for save/restore is identical to that used by the
     Whitehead Genome Center's data exchange format "Boulderio", and can be
     manipulated and even databased using Boulderio utilities.  See
       http://www.genome.wi.mit.edu/genome_software/other/boulder.html

     for further details.

     If you wish to use this method from the function-oriented (non-OO)
     interface, the exported name for this method is ssssaaaavvvveeee____ppppaaaarrrraaaammmmeeeetttteeeerrrrssss(((()))).

     UUUUSSSSIIIINNNNGGGG TTTTHHHHEEEE FFFFUUUUNNNNCCCCTTTTIIIIOOOONNNN----OOOORRRRIIIIEEEENNNNTTTTEEEEDDDD IIIINNNNTTTTEEEERRRRFFFFAAAACCCCEEEE

     To use the function-oriented interface, you must specify which CGI.pm
     routines or sets of routines to import into your script's namespace.
     There is a small overhead associated with this importation, but it isn't
     much.

        use CGI <list of methods>;

     The listed methods will be imported into the current package; you can
     call them directly without creating a CGI object first.  This example
     shows how to import the ppppaaaarrrraaaammmm(((()))) and hhhheeeeaaaaddddeeeerrrr(((()))) methods, and then use them
     directly:

        use CGI 'param','header';
        print header('text/plain');
        $zipcode = param('zipcode');

     More frequently, you'll import common sets of functions by referring to
     the gropus by name.  All function sets are preceded with a ":"  character
     as in ":html3" (for tags defined in the HTML 3 standard).

     Here is a list of the function sets you can import:






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     ::::ccccggggiiii
         Import all CGI-handling methods, such as ppppaaaarrrraaaammmm(((()))), ppppaaaatttthhhh____iiiinnnnffffoooo(((()))) and the
         like.

     ::::ffffoooorrrrmmmm
         Import all fill-out form generating methods, such as tttteeeexxxxttttffffiiiieeeelllldddd(((()))).

     ::::hhhhttttmmmmllll2222
         Import all methods that generate HTML 2.0 standard elements.

     ::::hhhhttttmmmmllll3333
         Import all methods that generate HTML 3.0 proposed elements (such as
         <table>, <super> and <sub>).

     ::::nnnneeeettttssssccccaaaappppeeee
         Import all methods that generate Netscape-specific HTML extensions.

     ::::hhhhttttmmmmllll
         Import all HTML-generating shortcuts (i.e. 'html2' + 'html3' +
         'netscape')...

     ::::ssssttttaaaannnnddddaaaarrrrdddd
         Import "standard" features, 'html2', 'html3', 'form' and 'cgi'.

     ::::aaaallllllll
         Import all the available methods.  For the full list, see the CGI.pm
         code, where the variable %TAGS is defined.

     If you import a function name that is not part of CGI.pm, the module will
     treat it as a new HTML tag and generate the appropriate subroutine.  You
     can then use it like any other HTML tag.  This is to provide for the
     rapidly-evolving HTML "standard."  For example, say Microsoft comes out
     with a new tag called <GRADIENT> (which causes the user's desktop to be
     flooded with a rotating gradient fill until his machine reboots).  You
     don't need to wait for a new version of CGI.pm to start using it
     immeidately:

        use CGI qw/:standard :html3 gradient/;
        print gradient({-start=>'red',-end=>'blue'});

     Note that in the interests of execution speed CGI.pm does nnnnooootttt use the
     standard the _E_x_p_o_r_t_e_r manpage syntax for specifying load symbols.  This
     may change in the future.

     If you import any of the state-maintaining CGI or form-generating
     methods, a default CGI object will be created and initialized
     automatically the first time you use any of the methods that require one
     to be present.  This includes ppppaaaarrrraaaammmm(((()))), tttteeeexxxxttttffffiiiieeeelllldddd(((()))), ssssuuuubbbbmmmmiiiitttt(((()))) and the
     like.  (If you need direct access to the CGI object, you can find it in
     the global variable $$$$CCCCGGGGIIII::::::::QQQQ).  By importing CGI.pm methods, you can
     create visually elegant scripts:




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        use CGI qw/:standard/;
        print
            header,
            start_html('Simple Script'),
            h1('Simple Script'),
            start_form,
            "What's your name? ",textfield('name'),p,
            "What's the combination?",
            checkbox_group(-name=>'words',
                           -values=>['eenie','meenie','minie','moe'],
                           -defaults=>['eenie','moe']),p,
            "What's your favorite color?",
            popup_menu(-name=>'color',
                       -values=>['red','green','blue','chartreuse']),p,
            submit,
            end_form,
            hr,"\n";

         if (param) {
            print
                "Your name is ",em(param('name')),p,
                "The keywords are: ",em(join(", ",param('words'))),p,
                "Your favorite color is ",em(param('color')),".\n";
         }
         print end_html;


     PPPPRRRRAAAAGGGGMMMMAAAASSSS

     In addition to the function sets, there are a number of pragmas that you
     can import.  Pragmas, which are always preceded by a hyphen, change the
     way that CGI.pm functions in various ways.  Pragmas, function sets, and
     individual functions can all be imported in the same _u_s_e() line.  For
     example, the following use statement imports the standard set of
     functions and disables debugging mode (pragma -no_debug):

        use CGI qw/:standard -no_debug/;

     The current list of pragmas is as follows:

     -any
         When you _u_s_e _C_G_I -_a_n_y, then any method that the query object doesn't
         recognize will be interpreted as a new HTML tag.  This allows you to
         support the next _a_d _h_o_c Netscape or Microsoft HTML extension.  This
         lets you go wild with new and unsupported tags:

            use CGI qw(-any);
            $q=new CGI;
            print $q->gradient({speed=>'fast',start=>'red',end=>'blue'});

         Since using <cite>any</cite> causes any mistyped method name to be
         interpreted as an HTML tag, use it with care or not at all.



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     -compile
         This causes the indicated autoloaded methods to be compiled up front,
         rather than deferred to later.  This is useful for scripts that run
         for an extended period of time under FastCGI or mod_perl, and for
         those destined to be crunched by Malcom Beattie's Perl compiler.  Use
         it in conjunction with the methods or method familes you plan to use.

            use CGI qw(-compile :standard :html3);

         or even

            use CGI qw(-compile :all);

         Note that using the -compile pragma in this way will always have the
         effect of importing the compiled functions into the current
         namespace.  If you want to compile without importing use the
         _c_o_m_p_i_l_e() method instead (see below).

     -nph
         This makes CGI.pm produce a header appropriate for an NPH (no parsed
         header) script.  You may need to do other things as well to tell the
         server that the script is NPH.  See the discussion of NPH scripts
         below.

     -autoload
         This overrides the autoloader so that any function in your program
         that is not recognized is referred to CGI.pm for possible evaluation.
         This allows you to use all the CGI.pm functions without adding them
         to your symbol table, which is of concern for mod_perl users who are
         worried about memory consumption.  _W_a_r_n_i_n_g: when -_a_u_t_o_l_o_a_d is in
         effect, you cannot use "poetry mode" (functions without the
         parenthesis).  Use _h_r() rather than _h_r, or add something like _u_s_e
         _s_u_b_s _q_w/_h_r _p _h_e_a_d_e_r/ to the top of your script.

     -no_debug
         This turns off the command-line processing features.  If you want to
         run a CGI.pm script from the command line to produce HTML, and you
         don't want it pausing to request CGI parameters from standard input
         or the command line, then use this pragma:

            use CGI qw(-no_debug :standard);

         If you'd like to process the command-line parameters but not standard
         input, this should work:

            use CGI qw(-no_debug :standard);
            restore_parameters(join('&',@ARGV));

         See the section on debugging for more details.






                                                                       PPPPaaaaggggeeee 11112222






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     -private_tempfiles
         CGI.pm can process uploaded file. Ordinarily it spools the uploaded
         file to a temporary directory, then deletes the file when done.
         However, this opens the risk of eavesdropping as described in the
         file upload section.  Another CGI script author could peek at this
         data during the upload, even if it is confidential information. On
         Unix systems, the -private_tempfiles pragma will cause the temporary
         file to be unlinked as soon as it is opened and before any data is
         written into it, eliminating the risk of eavesdropping.  n =back

GGGGEEEENNNNEEEERRRRAAAATTTTIIIINNNNGGGG DDDDYYYYNNNNAAAAMMMMIIIICCCC DDDDOOOOCCCCUUUUMMMMEEEENNNNTTTTSSSS
     Most of CGI.pm's functions deal with creating documents on the fly.
     Generally you will produce the HTTP header first, followed by the
     document itself.  CGI.pm provides functions for generating HTTP headers
     of various types as well as for generating HTML.  For creating GIF
     images, see the GD.pm module.

     Each of these functions produces a fragment of HTML or HTTP which you can
     print out directly so that it displays in the browser window, append to a
     string, or save to a file for later use.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA SSSSTTTTAAAANNNNDDDDAAAARRRRDDDD HHHHTTTTTTTTPPPP HHHHEEEEAAAADDDDEEEERRRR::::

     Normally the first thing you will do in any CGI script is print out an
     HTTP header.  This tells the browser what type of document to expect, and
     gives other optional information, such as the language, expiration date,
     and whether to cache the document.  The header can also be manipulated
     for special purposes, such as server push and pay per view pages.

             print $query->header;

                  -or-

             print $query->header('image/gif');

                  -or-

             print $query->header('text/html','204 No response');

                  -or-

             print $query->header(-type=>'image/gif',
                                  -nph=>1,
                                  -status=>'402 Payment required',
                                  -expires=>'+3d',
                                  -cookie=>$cookie,
                                  -Cost=>'$2.00');

     _h_e_a_d_e_r() returns the Content-type: header.  You can provide your own MIME
     type if you choose, otherwise it defaults to text/html.  An optional
     second parameter specifies the status code and a human-readable message.
     For example, you can specify 204, "No response" to create a script that



                                                                       PPPPaaaaggggeeee 11113333






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     tells the browser to do nothing at all.

     The last example shows the named argument style for passing arguments to
     the CGI methods using named parameters.  Recognized parameters are ----ttttyyyyppppeeee,
     ----ssssttttaaaattttuuuussss, ----eeeexxxxppppiiiirrrreeeessss, and ----ccccooooooookkkkiiiieeee.  Any other named parameters will be
     stripped of their initial hyphens and turned into header fields, allowing
     you to specify any HTTP header you desire.  Internal underscores will be
     turned into hyphens:

         print $query->header(-Content_length=>3002);

     Most browsers will not cache the output from CGI scripts.  Every time the
     browser reloads the page, the script is invoked anew.  You can change
     this behavior with the ----eeeexxxxppppiiiirrrreeeessss parameter.  When you specify an absolute
     or relative expiration interval with this parameter, some browsers and
     proxy servers will cache the script's output until the indicated
     expiration date.  The following forms are all valid for the -expires
     field:

             +30s                              30 seconds from now
             +10m                              ten minutes from now
             +1h                               one hour from now
             -1d                               yesterday (i.e. "ASAP!")
             now                               immediately
             +3M                               in three months
             +10y                              in ten years time
             Thursday, 25-Apr-1999 00:40:33 GMT  at the indicated time & date

     The ----ccccooooooookkkkiiiieeee parameter generates a header that tells the browser to
     provide a "magic cookie" during all subsequent transactions with your
     script.  Netscape cookies have a special format that includes interesting
     attributes such as expiration time.  Use the _c_o_o_k_i_e() method to create
     and retrieve session cookies.

     The ----nnnnpppphhhh parameter, if set to a true value, will issue the correct
     headers to work with a NPH (no-parse-header) script.  This is important
     to use with certain servers, such as Microsoft Internet Explorer, which
     expect all their scripts to be NPH.

     GGGGEEEENNNNEEEERRRRAAAATTTTIIIINNNNGGGG AAAA RRRREEEEDDDDIIIIRRRREEEECCCCTTTTIIIIOOOONNNN HHHHEEEEAAAADDDDEEEERRRR

        print $query->redirect('http://somewhere.else/in/movie/land');

     Sometimes you don't want to produce a document yourself, but simply
     redirect the browser elsewhere, perhaps choosing a URL based on the time
     of day or the identity of the user.

     The _r_e_d_i_r_e_c_t() function redirects the browser to a different URL.  If you
     use redirection like this, you should nnnnooootttt print out a header as well.  As
     of version 2.0, we produce both the unofficial Location:  header and the
     official URI: header.  This should satisfy most servers and browsers.




                                                                       PPPPaaaaggggeeee 11114444






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     One hint I can offer is that relative links may not work correctly when
     you generate a redirection to another document on your site.  This is due
     to a well-intentioned optimization that some servers use.  The solution
     to this is to use the full URL (including the http: part) of the document
     you are redirecting to.

     You can also use named arguments:

         print $query->redirect(-uri=>'http://somewhere.else/in/movie/land',
                                -nph=>1);

     The ----nnnnpppphhhh parameter, if set to a true value, will issue the correct
     headers to work with a NPH (no-parse-header) script.  This is important
     to use with certain servers, such as Microsoft Internet Explorer, which
     expect all their scripts to be NPH.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG TTTTHHHHEEEE HHHHTTTTMMMMLLLL DDDDOOOOCCCCUUUUMMMMEEEENNNNTTTT HHHHEEEEAAAADDDDEEEERRRR

        print $query->start_html(-title=>'Secrets of the Pyramids',
                                 -author=>'[e-mail]',
                                 -base=>'true',
                                 -target=>'_blank',
                                 -meta=>{'keywords'=>'pharaoh secret mummy',
                                         'copyright'=>'copyright 1996 King Tut'},
                                 -style=>{'src'=>'/styles/style1.css'},
                                 -BGCOLOR=>'blue');

     After creating the HTTP header, most CGI scripts will start writing out
     an HTML document.  The _s_t_a_r_t__h_t_m_l() routine creates the top of the page,
     along with a lot of optional information that controls the page's
     appearance and behavior.

     This method returns a canned HTML header and the opening <BODY> tag.  All
     parameters are optional.  In the named parameter form, recognized
     parameters are -title, -author, -base, -xbase and -target (see below for
     the explanation).  Any additional parameters you provide, such as the
     Netscape unofficial BGCOLOR attribute, are added to the <BODY> tag.
     Additional parameters must be proceeded by a hyphen.

     The argument ----xxxxbbbbaaaasssseeee allows you to provide an HREF for the <BASE> tag
     different from the current location, as in

         -xbase=>"http://home.mcom.com/"

     All relative links will be interpreted relative to this tag.

     The argument ----ttttaaaarrrrggggeeeetttt allows you to provide a default target frame for all
     the links and fill-out forms on the page.  See the Netscape documentation
     on frames for details of how to manipulate this.

         -target=>"answer_window"




                                                                       PPPPaaaaggggeeee 11115555






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     All relative links will be interpreted relative to this tag.  You add
     arbitrary meta information to the header with the ----mmmmeeeettttaaaa argument.  This
     argument expects a reference to an associative array containing
     name/value pairs of meta information.  These will be turned into a series
     of header <META> tags that look something like this:

         <META NAME="keywords" CONTENT="pharaoh secret mummy">
         <META NAME="description" CONTENT="copyright 1996 King Tut">

     There is no support for the HTTP-EQUIV type of <META> tag.  This is
     because you can modify the HTTP header directly with the hhhheeeeaaaaddddeeeerrrr(((()))) method.
     For example, if you want to send the Refresh: header, do it in the
     _h_e_a_d_e_r() method:

         print $q->header(-Refresh=>'10; URL=http://www.capricorn.com');

     The ----ssssttttyyyylllleeee tag is used to incorporate cascading stylesheets into your
     code.  See the section on CASCADING STYLESHEETS for more information.

     You can place other arbitrary HTML elements to the <HEAD> section with
     the ----hhhheeeeaaaadddd tag.  For example, to place the rarely-used <LINK> element in
     the head section, use this:

         print $q->start_html(-head=>Link({-rel=>'next',
                                       -href=>'http://www.capricorn.com/s2.html'}));

     To incorporate multiple HTML elements into the <HEAD> section, just pass
     an array reference:

         print $q->start_html(-head=>[
                                   Link({-rel=>'next',
                                         -href=>'http://www.capricorn.com/s2.html'}),
                                   Link({-rel=>'previous',
                                         -href=>'http://www.capricorn.com/s1.html'})
                                  ]
                          );

     JAVASCRIPTING: The ----ssssccccrrrriiiipppptttt, ----nnnnooooSSSSccccrrrriiiipppptttt, ----oooonnnnLLLLooooaaaadddd, ----oooonnnnMMMMoooouuuusssseeeeOOOOvvvveeeerrrr, ----oooonnnnMMMMoooouuuusssseeeeOOOOuuuutttt
     and ----oooonnnnUUUUnnnnllllooooaaaadddd parameters are used to add Netscape JavaScript calls to
     your pages.  ----ssssccccrrrriiiipppptttt should point to a block of text containing
     JavaScript function definitions.  This block will be placed within a
     <SCRIPT> block inside the HTML (not HTTP) header.  The block is placed in
     the header in order to give your page a fighting chance of having all its
     JavaScript functions in place even if the user presses the stop button
     before the page has loaded completely.  CGI.pm attempts to format the
     script in such a way that JavaScript-naive browsers will not choke on the
     code: unfortunately there are some browsers, such as Chimera for Unix,
     that get confused by it nevertheless.

     The ----oooonnnnLLLLooooaaaadddd and ----oooonnnnUUUUnnnnllllooooaaaadddd parameters point to fragments of JavaScript
     code to execute when the page is respectively opened and closed by the
     browser.  Usually these parameters are calls to functions defined in the



                                                                       PPPPaaaaggggeeee 11116666






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     ----ssssccccrrrriiiipppptttt field:

           $query = new CGI;
           print $query->header;
           $JSCRIPT=<<END;
           // Ask a silly question
           function riddle_me_this() {
              var r = prompt("What walks on four legs in the morning, " +
                            "two legs in the afternoon, " +
                            "and three legs in the evening?");
              response(r);
           }
           // Get a silly answer
           function response(answer) {
              if (answer == "man")
                 alert("Right you are!");
              else
                 alert("Wrong!  Guess again.");
           }
           END
           print $query->start_html(-title=>'The Riddle of the Sphinx',
                                    -script=>$JSCRIPT);

     Use the ----nnnnooooSSSSccccrrrriiiipppptttt parameter to pass some HTML text that will be displayed
     on browsers that do not have JavaScript (or browsers where JavaScript is
     turned off).

     Netscape 3.0 recognizes several attributes of the <SCRIPT> tag, including
     LANGUAGE and SRC.  The latter is particularly interesting, as it allows
     you to keep the JavaScript code in a file or CGI script rather than
     cluttering up each page with the source.  To use these attributes pass a
     HASH reference in the ----ssssccccrrrriiiipppptttt parameter containing one or more of
     -language, -src, or -code:

         print $q->start_html(-title=>'The Riddle of the Sphinx',
                              -script=>{-language=>'JAVASCRIPT',
                                        -src=>'/javascript/sphinx.js'}
                              );

         print $q->(-title=>'The Riddle of the Sphinx',
                    -script=>{-language=>'PERLSCRIPT'},
                              -code=>'print "hello world!\n;"'
                    );

     A final feature allows you to incorporate multiple <SCRIPT> sections into
     the header.  Just pass the list of script sections as an array reference.
     this allows you to specify different source files for different dialects
     of JavaScript.  Example:







                                                                       PPPPaaaaggggeeee 11117777






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



          print $q->start_html(-title=>'The Riddle of the Sphinx',
                               -script=>[
                                         { -language => 'JavaScript1.0',
                                           -src      => '/javascript/utilities10.js'
                                         },
                                         { -language => 'JavaScript1.1',
                                           -src      => '/javascript/utilities11.js'
                                         },
                                         { -language => 'JavaScript1.2',
                                           -src      => '/javascript/utilities12.js'
                                         },
                                         { -language => 'JavaScript28.2',
                                           -src      => '/javascript/utilities219.js'
                                         }
                                      ]
                                  );
          </pre>

     If this looks a bit extreme, take my advice and stick with straight CGI
     scripting.

     See

        http://home.netscape.com/eng/mozilla/2.0/handbook/javascript/

     for more information about JavaScript.

     The old-style positional parameters are as follows:

     PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss::::

     1.      The title

     2.      The author's e-mail address (will create a <LINK REV="MADE"> tag
             if present

     3.      A 'true' flag if you want to include a <BASE> tag in the header.
             This helps resolve relative addresses to absolute ones when the
             document is moved, but makes the document hierarchy non-portable.
             Use with care!

     4, 5, 6...
             Any other parameters you want to include in the <BODY> tag.  This
             is a good place to put Netscape extensions, such as colors and
             wallpaper patterns.

     EEEENNNNDDDDIIIINNNNGGGG TTTTHHHHEEEE HHHHTTTTMMMMLLLL DDDDOOOOCCCCUUUUMMMMEEEENNNNTTTT::::

             print $query->end_html

     This ends an HTML document by printing the </BODY></HTML> tags.




                                                                       PPPPaaaaggggeeee 11118888






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA SSSSEEEELLLLFFFF----RRRREEEEFFFFEEEERRRREEEENNNNCCCCIIIINNNNGGGG UUUURRRRLLLL TTTTHHHHAAAATTTT PPPPRRRREEEESSSSEEEERRRRVVVVEEEESSSS SSSSTTTTAAAATTTTEEEE IIIINNNNFFFFOOOORRRRMMMMAAAATTTTIIIIOOOONNNN::::

         $myself = $query->self_url;
         print "<A HREF=$myself>I'm talking to myself.</A>";

     _s_e_l_f__u_r_l() will return a URL, that, when selected, will reinvoke this
     script with all its state information intact.  This is most useful when
     you want to jump around within the document using internal anchors but
     you don't want to disrupt the current contents of the _f_o_r_m(s).  Something
     like this will do the trick.

          $myself = $query->self_url;
          print "<A HREF=$myself#table1>See table 1</A>";
          print "<A HREF=$myself#table2>See table 2</A>";
          print "<A HREF=$myself#yourself>See for yourself</A>";

     If you want more control over what's returned, using the uuuurrrrllll(((()))) method
     instead.

     You can also retrieve the unprocessed query string with _q_u_e_r_y__s_t_r_i_n_g():

         $the_string = $query->query_string;


     OOOOBBBBTTTTAAAAIIIINNNNIIIINNNNGGGG TTTTHHHHEEEE SSSSCCCCRRRRIIIIPPPPTTTT''''SSSS UUUURRRRLLLL

         $full_url      = $query->url();
         $full_url      = $query->url(-full=>1);  #alternative syntax
         $relative_url  = $query->url(-relative=>1);
         $absolute_url  = $query->url(-absolute=>1);
         $url_with_path = $query->url(-path_info=>1);
         $url_with_path_and_query = $query->url(-path_info=>1,-query=>1);

     uuuurrrrllll(((()))) returns the script's URL in a variety of formats.  Called without
     any arguments, it returns the full form of the URL, including host name
     and port number

         http://your.host.com/path/to/script.cgi

     You can modify this format with the following named arguments:

     ----aaaabbbbssssoooolllluuuutttteeee
             If true, produce an absolute URL, e.g.

                 /path/to/script.cgi


     ----rrrreeeellllaaaattttiiiivvvveeee
             Produce a relative URL.  This is useful if you want to reinvoke
             your script with different parameters. For example:

                 script.cgi



                                                                       PPPPaaaaggggeeee 11119999






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     ----ffffuuuullllllll   Produce the full URL, exactly as if called without any arguments.
             This overrides the -relative and -absolute arguments.

     ----ppppaaaatttthhhh (----ppppaaaatttthhhh____iiiinnnnffffoooo)
             Append the additional path information to the URL.  This can be
             combined with ----ffffuuuullllllll, ----aaaabbbbssssoooolllluuuutttteeee or ----rrrreeeellllaaaattttiiiivvvveeee.  ----ppppaaaatttthhhh____iiiinnnnffffoooo is
             provided as a synonym.

     ----qqqquuuueeeerrrryyyy (----qqqquuuueeeerrrryyyy____ssssttttrrrriiiinnnngggg)
             Append the query string to the URL.  This can be combined with
             ----ffffuuuullllllll, ----aaaabbbbssssoooolllluuuutttteeee or ----rrrreeeellllaaaattttiiiivvvveeee.  ----qqqquuuueeeerrrryyyy____ssssttttrrrriiiinnnngggg is provided as a
             synonym.

CCCCRRRREEEEAAAATTTTIIIINNNNGGGG SSSSTTTTAAAANNNNDDDDAAAARRRRDDDD HHHHTTTTMMMMLLLL EEEELLLLEEEEMMMMEEEENNNNTTTTSSSS::::
     CGI.pm defines general HTML shortcut methods for most, if not all of the
     HTML 3 and HTML 4 tags.  HTML shortcuts are named after a single HTML
     element and return a fragment of HTML text that you can then print or
     manipulate as you like.  Each shortcut returns a fragment of HTML code
     that you can append to a string, save to a file, or, most commonly, print
     out so that it displays in the browser window.

     This example shows how to use the HTML methods:

        $q = new CGI;
        print $q->blockquote(
                          "Many years ago on the island of",
                          $q->a({href=>"http://crete.org/"},"Crete"),
                          "there lived a minotaur named",
                          $q->strong("Fred."),
                         ),
            $q->hr;

     This results in the following HTML code (extra newlines have been added
     for readability):

        <blockquote>
        Many years ago on the island of
        <a HREF="http://crete.org/">Crete</a> there lived
        a minotaur named <strong>Fred.</strong>
        </blockquote>
        <hr>

     If you find the syntax for calling the HTML shortcuts awkward, you can
     import them into your namespace and dispense with the object syntax
     completely (see the next section for more details):










                                                                       PPPPaaaaggggeeee 22220000






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



        use CGI ':standard';
        print blockquote(
           "Many years ago on the island of",
           a({href=>"http://crete.org/"},"Crete"),
           "there lived a minotaur named",
           strong("Fred."),
           ),
           hr;


     PPPPRRRROOOOVVVVIIIIDDDDIIIINNNNGGGG AAAARRRRGGGGUUUUMMMMEEEENNNNTTTTSSSS TTTTOOOO HHHHTTTTMMMMLLLL SSSSHHHHOOOORRRRTTTTCCCCUUUUTTTTSSSS

     The HTML methods will accept zero, one or multiple arguments.  If you
     provide no arguments, you get a single tag:

        print hr;    #  <HR>

     If you provide one or more string arguments, they are concatenated
     together with spaces and placed between opening and closing tags:

        print h1("Chapter","1"); # <H1>Chapter 1</H1>"

     If the first argument is an associative array reference, then the keys
     and values of the associative array become the HTML tag's attributes:

        print a({-href=>'fred.html',-target=>'_new'},
           "Open a new frame");

                 <A HREF="fred.html",TARGET="_new">Open a new frame</A>

     You may dispense with the dashes in front of the attribute names if
     you prefer:

        print img {src=>'fred.gif',align=>'LEFT'};

                <IMG ALIGN="LEFT" SRC="fred.gif">

     Sometimes an HTML tag attribute has no argument.  For example, ordered
     lists can be marked as COMPACT.  The syntax for this is an argument that
     that points to an undef string:

        print ol({compact=>undef},li('one'),li('two'),li('three'));

     Prior to CGI.pm version 2.41, providing an empty ('') string as an
     attribute argument was the same as providing undef.  However, this has
     changed in order to accomodate those who want to create tags of the form
     <IMG ALT="">.  The difference is shown in these two pieces of code:

        CODE                   RESULT
        _i_m_g({alt=>undef})      <IMG ALT>
        _i_m_g({alt=>''})         <IMT ALT="">




                                                                       PPPPaaaaggggeeee 22221111






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     TTTTHHHHEEEE DDDDIIIISSSSTTTTRRRRIIIIBBBBUUUUTTTTIIIIVVVVEEEE PPPPRRRROOOOPPPPEEEERRRRTTTTYYYY OOOOFFFF HHHHTTTTMMMMLLLL SSSSHHHHOOOORRRRTTTTCCCCUUUUTTTTSSSS

     One of the cool features of the HTML shortcuts is that they are
     distributive.  If you give them an argument consisting of a rrrreeeeffffeeeerrrreeeennnncccceeee to
     a list, the tag will be distributed across each element of the list.  For
     example, here's one way to make an ordered list:

        print ul(
                  li({-type=>'disc'},['Sneezy','Doc','Sleepy','Happy']);
                );

     This example will result in HTML output that looks like this:

        <UL>
          <LI TYPE="disc">Sneezy</LI>
          <LI TYPE="disc">Doc</LI>
          <LI TYPE="disc">Sleepy</LI>
          <LI TYPE="disc">Happy</LI>
        </UL>

     This is extremely useful for creating tables.  For example:

        print table({-border=>undef},
                caption('When Should You Eat Your Vegetables?'),
                Tr({-align=>CENTER,-valign=>TOP},
                [
                   th(['Vegetable', 'Breakfast','Lunch','Dinner']),
                   td(['Tomatoes' , 'no', 'yes', 'yes']),
                   td(['Broccoli' , 'no', 'no',  'yes']),
                   td(['Onions'   , 'yes','yes', 'yes'])
                ]
                )
             );


     HHHHTTTTMMMMLLLL SSSSHHHHOOOORRRRTTTTCCCCUUUUTTTTSSSS AAAANNNNDDDD LLLLIIIISSSSTTTT IIIINNNNTTTTEEEERRRRPPPPOOOOLLLLAAAATTTTIIIIOOOONNNN

     Consider this bit of code:

        print blockquote(em('Hi'),'mom!'));

     It will ordinarily return the string that you probably expect, namely:

        <BLOCKQUOTE><EM>Hi</EM> mom!</BLOCKQUOTE>

     Note the space between the element "Hi" and the element "mom!".  CGI.pm
     puts the extra space there using array interpolation, which is controlled
     by the magic $" variable.  Sometimes this extra space is not what you
     want, for example, when you are trying to align a series of images.  In
     this case, you can simply change the value of $" to an empty string.





                                                                       PPPPaaaaggggeeee 22222222






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



        {
           local($") = '';
           print blockquote(em('Hi'),'mom!'));
         }

     I suggest you put the code in a block as shown here.  Otherwise the
     change to $" will affect all subsequent code until you explicitly reset
     it.

     NNNNOOOONNNN----SSSSTTTTAAAANNNNDDDDAAAARRRRDDDD HHHHTTTTMMMMLLLL SSSSHHHHOOOORRRRTTTTCCCCUUUUTTTTSSSS

     A few HTML tags don't follow the standard pattern for various reasons.

     ccccoooommmmmmmmeeeennnntttt(((()))) generates an HTML comment (<!-- comment -->).  Call it like

         print comment('here is my comment');

     Because of conflicts with built-in Perl functions, the following
     functions begin with initial caps:

         Select
         Tr
         Link
         Delete

     In addition, _s_t_a_r_t__h_t_m_l(), _e_n_d__h_t_m_l(), _s_t_a_r_t__f_o_r_m(), _e_n_d__f_o_r_m(),
     _s_t_a_r_t__m_u_l_t_i_p_a_r_t__f_o_r_m() and all the fill-out form tags are special.  See
     their respective sections.

CCCCRRRREEEEAAAATTTTIIIINNNNGGGG FFFFIIIILLLLLLLL----OOOOUUUUTTTT FFFFOOOORRRRMMMMSSSS::::
     _G_e_n_e_r_a_l _n_o_t_e  The various form-creating methods all return strings to the
     caller, containing the tag or tags that will create the requested form
     element.  You are responsible for actually printing out these strings.
     It's set up this way so that you can place formatting tags around the
     form elements.

     _A_n_o_t_h_e_r _n_o_t_e The default values that you specify for the forms are only
     used the ffffiiiirrrrsssstttt time the script is invoked (when there is no query
     string).  On subsequent invocations of the script (when there is a query
     string), the former values are used even if they are blank.

     If you want to change the value of a field from its previous value, you
     have two choices:

     (1) call the _p_a_r_a_m() method to set it.

     (2) use the -override (alias -force) parameter (a new feature in version
     2.15).  This forces the default value to be used, regardless of the
     previous value:






                                                                       PPPPaaaaggggeeee 22223333






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



        print $query->textfield(-name=>'field_name',
                                -default=>'starting value',
                                -override=>1,
                                -size=>50,
                                -maxlength=>80);

     _Y_e_t _a_n_o_t_h_e_r _n_o_t_e By default, the text and labels of form elements are
     escaped according to HTML rules.  This means that you can safely use
     "<CLICK ME>" as the label for a button.  However, it also interferes with
     your ability to incorporate special HTML character sequences, such as
     Á, into your fields.  If you wish to turn off automatic escaping,
     call the _a_u_t_o_E_s_c_a_p_e() method with a false value immediately after
     creating the CGI object:

        $query = new CGI;
        $query->autoEscape(undef);



     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAANNNN IIIISSSSIIIINNNNDDDDEEEEXXXX TTTTAAAAGGGG

        print $query->isindex(-action=>$action);

              -or-

        print $query->isindex($action);

     Prints out an <ISINDEX> tag.  Not very exciting.  The parameter -action
     specifies the URL of the script to process the query.  The default is to
     process the query with the current script.

     SSSSTTTTAAAARRRRTTTTIIIINNNNGGGG AAAANNNNDDDD EEEENNNNDDDDIIIINNNNGGGG AAAA FFFFOOOORRRRMMMM

         print $query->startform(-method=>$method,
                                 -action=>$action,
                                 -encoding=>$encoding);
           <... various form stuff ...>
         print $query->endform;

             -or-

         print $query->startform($method,$action,$encoding);
           <... various form stuff ...>
         print $query->endform;

     _s_t_a_r_t_f_o_r_m() will return a <FORM> tag with the optional method, action and
     form encoding that you specify.  The defaults are:
         method: POST
         action: this script
         encoding: application/x-www-form-urlencoded

     _e_n_d_f_o_r_m() returns the closing </FORM> tag.



                                                                       PPPPaaaaggggeeee 22224444






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     _S_t_a_r_t_f_o_r_m()'s encoding method tells the browser how to package the
     various fields of the form before sending the form to the server.  Two
     values are possible:

     aaaapppppppplllliiiiccccaaaattttiiiioooonnnn////xxxx----wwwwwwwwwwww----ffffoooorrrrmmmm----uuuurrrrlllleeeennnnccccooooddddeeeedddd
             This is the older type of encoding used by all browsers prior to
             Netscape 2.0.  It is compatible with many CGI scripts and is
             suitable for short fields containing text data.  For your
             convenience, CGI.pm stores the name of this encoding type in
             $$$$CCCCGGGGIIII::::::::UUUURRRRLLLL____EEEENNNNCCCCOOOODDDDEEEEDDDD.

     mmmmuuuullllttttiiiippppaaaarrrrtttt////ffffoooorrrrmmmm----ddddaaaattttaaaa
             This is the newer type of encoding introduced by Netscape 2.0.
             It is suitable for forms that contain very large fields or that
             are intended for transferring binary data.  Most importantly, it
             enables the "file upload" feature of Netscape 2.0 forms.  For
             your convenience, CGI.pm stores the name of this encoding type in
             &&&&CCCCGGGGIIII::::::::MMMMUUUULLLLTTTTIIIIPPPPAAAARRRRTTTT

             Forms that use this type of encoding are not easily interpreted
             by CGI scripts unless they use CGI.pm or another library designed
             to handle them.

             For compatibility, the _s_t_a_r_t_f_o_r_m() method uses the older form of
             encoding by default.  If you want to use the newer form of
             encoding by default, you can call ssssttttaaaarrrrtttt____mmmmuuuullllttttiiiippppaaaarrrrtttt____ffffoooorrrrmmmm(((()))) instead
             of ssssttttaaaarrrrttttffffoooorrrrmmmm(((()))).

             JAVASCRIPTING: The ----nnnnaaaammmmeeee and ----oooonnnnSSSSuuuubbbbmmmmiiiitttt parameters are provided
             for use with JavaScript.  The -name parameter gives the form a
             name so that it can be identified and manipulated by JavaScript
             functions.  -onSubmit should point to a JavaScript function that
             will be executed just before the form is submitted to your
             server.  You can use this opportunity to check the contents of
             the form for consistency and completeness.  If you find something
             wrong, you can put up an alert box or maybe fix things up
             yourself.  You can abort the submission by returning false from
             this function.

             Usually the bulk of JavaScript functions are defined in a
             <SCRIPT> block in the HTML header and -onSubmit points to one of
             these function call.  See _s_t_a_r_t__h_t_m_l() for details.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA TTTTEEEEXXXXTTTT FFFFIIIIEEEELLLLDDDD

         print $query->textfield(-name=>'field_name',
                                 -default=>'starting value',
                                 -size=>50,
                                 -maxlength=>80);
             -or-

         print $query->textfield('field_name','starting value',50,80);



                                                                       PPPPaaaaggggeeee 22225555






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     _t_e_x_t_f_i_e_l_d() will return a text input field.

     PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss

     1.      The first parameter is the required name for the field (-name).

     2.      The optional second parameter is the default starting value for
             the field contents (-default).

     3.      The optional third parameter is the size of the field in
                   characters (-size).

     4.      The optional fourth parameter is the maximum number of characters
             the
                   field will accept (-maxlength).

             As with all these methods, the field will be initialized with its
             previous contents from earlier invocations of the script.  When
             the form is processed, the value of the text field can be
             retrieved with:

                    $value = $query->param('foo');

             If you want to reset it from its initial value after the script
             has been called once, you can do so like this:

                    $query->param('foo',"I'm taking over this value!");

             NEW AS OF VERSION 2.15: If you don't want the field to take on
             its previous value, you can force its current value by using the
             -override (alias -force) parameter:

                 print $query->textfield(-name=>'field_name',
                                         -default=>'starting value',
                                         -override=>1,
                                         -size=>50,
                                         -maxlength=>80);

             JAVASCRIPTING: You can also provide ----oooonnnnCCCChhhhaaaannnnggggeeee, ----oooonnnnFFFFooooccccuuuussss, ----oooonnnnBBBBlllluuuurrrr,
             ----oooonnnnMMMMoooouuuusssseeeeOOOOvvvveeeerrrr, ----oooonnnnMMMMoooouuuusssseeeeOOOOuuuutttt and ----oooonnnnSSSSeeeelllleeeecccctttt parameters to register
             JavaScript event handlers.  The onChange handler will be called
             whenever the user changes the contents of the text field.  You
             can do text validation if you like.  onFocus and onBlur are
             called respectively when the insertion point moves into and out
             of the text field.  onSelect is called when the user changes the
             portion of the text that is selected.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA BBBBIIIIGGGG TTTTEEEEXXXXTTTT FFFFIIIIEEEELLLLDDDD







                                                                       PPPPaaaaggggeeee 22226666






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



        print $query->textarea(-name=>'foo',
                               -default=>'starting value',
                               -rows=>10,
                               -columns=>50);

             -or

        print $query->textarea('foo','starting value',10,50);

     _t_e_x_t_a_r_e_a() is just like textfield, but it allows you to specify rows and
     columns for a multiline text entry box.  You can provide a starting value
     for the field, which can be long and contain multiple lines.

     JAVASCRIPTING: The ----oooonnnnCCCChhhhaaaannnnggggeeee, ----oooonnnnFFFFooooccccuuuussss, ----oooonnnnBBBBlllluuuurrrr , ----oooonnnnMMMMoooouuuusssseeeeOOOOvvvveeeerrrr,
     ----oooonnnnMMMMoooouuuusssseeeeOOOOuuuutttt, and ----oooonnnnSSSSeeeelllleeeecccctttt parameters are recognized.  See _t_e_x_t_f_i_e_l_d().

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA PPPPAAAASSSSSSSSWWWWOOOORRRRDDDD FFFFIIIIEEEELLLLDDDD

        print $query->password_field(-name=>'secret',
                                     -value=>'starting value',
                                     -size=>50,
                                     -maxlength=>80);
             -or-

        print $query->password_field('secret','starting value',50,80);

     _p_a_s_s_w_o_r_d__f_i_e_l_d() is identical to _t_e_x_t_f_i_e_l_d(), except that its contents
     will be starred out on the web page.

     JAVASCRIPTING: The ----oooonnnnCCCChhhhaaaannnnggggeeee, ----oooonnnnFFFFooooccccuuuussss, ----oooonnnnBBBBlllluuuurrrr, ----oooonnnnMMMMoooouuuusssseeeeOOOOvvvveeeerrrr,
     ----oooonnnnMMMMoooouuuusssseeeeOOOOuuuutttt and ----oooonnnnSSSSeeeelllleeeecccctttt parameters are recognized.  See _t_e_x_t_f_i_e_l_d().

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA FFFFIIIILLLLEEEE UUUUPPPPLLLLOOOOAAAADDDD FFFFIIIIEEEELLLLDDDD

         print $query->filefield(-name=>'uploaded_file',
                                 -default=>'starting value',
                                 -size=>50,
                                 -maxlength=>80);
             -or-

         print $query->filefield('uploaded_file','starting value',50,80);

     _f_i_l_e_f_i_e_l_d() will return a file upload field for Netscape 2.0 browsers.
     In order to take full advantage of this _y_o_u _m_u_s_t _u_s_e _t_h_e _n_e_w _m_u_l_t_i_p_a_r_t
     _e_n_c_o_d_i_n_g _s_c_h_e_m_e for the form.  You can do this either by calling
     ssssttttaaaarrrrttttffffoooorrrrmmmm(((()))) with an encoding type of $$$$CCCCGGGGIIII::::::::MMMMUUUULLLLTTTTIIIIPPPPAAAARRRRTTTT, or by calling the
     new method ssssttttaaaarrrrtttt____mmmmuuuullllttttiiiippppaaaarrrrtttt____ffffoooorrrrmmmm(((()))) instead of vanilla ssssttttaaaarrrrttttffffoooorrrrmmmm(((()))).

     PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss






                                                                       PPPPaaaaggggeeee 22227777






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     1.      The first parameter is the required name for the field (-name).

     2.      The optional second parameter is the starting value for the field
             contents to be used as the default file name (-default).

             The beta2 version of Netscape 2.0 currently doesn't pay any
             attention to this field, and so the starting value will always be
             blank.  Worse, the field loses its "sticky" behavior and forgets
             its previous contents.  The starting value field is called for in
             the HTML specification, however, and possibly later versions of
             Netscape will honor it.

     3.      The optional third parameter is the size of the field in
             characters (-size).

     4.      The optional fourth parameter is the maximum number of characters
             the field will accept (-maxlength).

             When the form is processed, you can retrieve the entered filename
             by calling _p_a_r_a_m().

                    $filename = $query->param('uploaded_file');

             In Netscape Navigator 2.0, the filename that gets returned is the
             full local filename on the rrrreeeemmmmooootttteeee uuuusssseeeerrrr''''ssss machine.  If the remote
             user is on a Unix machine, the filename will follow Unix
             conventions:

                     /path/to/the/file

             On an MS-DOS/Windows and OS/2 machines, the filename will follow
             DOS conventions:

                     C:\PATH\TO\THE\FILE.MSW

             On a Macintosh machine, the filename will follow Mac conventions:

                     HD 40:Desktop Folder:Sort Through:Reminders

             The filename returned is also a file handle.  You can read the
             contents of the file using standard Perl file reading calls:

                     # Read a text file and print it out
                     while (<$filename>) {
                        print;
                     }

                     # Copy a binary file to somewhere safe
                     open (OUTFILE,">>/usr/local/web/users/feedback");
                     while ($bytesread=read($filename,$buffer,1024)) {
                        print OUTFILE $buffer;
                     }



                                                                       PPPPaaaaggggeeee 22228888






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



             When a file is uploaded the browser usually sends along some
             information along with it in the format of headers.  The
             information usually includes the MIME content type.  Future
             browsers may send other information as well (such as modification
             date and size). To retrieve this information, call _u_p_l_o_a_d_I_n_f_o().
             It returns a reference to an associative array containing all the
             document headers.

                    $filename = $query->param('uploaded_file');
                    $type = $query->uploadInfo($filename)->{'Content-Type'};
                    unless ($type eq 'text/html') {
                       die "HTML FILES ONLY!";
                    }

             If you are using a machine that recognizes "text" and "binary"
             data modes, be sure to understand when and how to use them (see
             the Camel book). Otherwise you may find that binary files are
             corrupted during file uploads.

             JAVASCRIPTING: The ----oooonnnnCCCChhhhaaaannnnggggeeee, ----oooonnnnFFFFooooccccuuuussss, ----oooonnnnBBBBlllluuuurrrr, ----oooonnnnMMMMoooouuuusssseeeeOOOOvvvveeeerrrr,
             ----oooonnnnMMMMoooouuuusssseeeeOOOOuuuutttt and ----oooonnnnSSSSeeeelllleeeecccctttt parameters are recognized.  See
             _t_e_x_t_f_i_e_l_d() for details.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA PPPPOOOOPPPPUUUUPPPP MMMMEEEENNNNUUUU

        print $query->popup_menu('menu_name',
                                 ['eenie','meenie','minie'],
                                 'meenie');

           -or-

        %labels = ('eenie'=>'your first choice',
                   'meenie'=>'your second choice',
                   'minie'=>'your third choice');
        print $query->popup_menu('menu_name',
                                 ['eenie','meenie','minie'],
                                 'meenie',\%labels);

             -or (named parameter style)-

        print $query->popup_menu(-name=>'menu_name',
                                 -values=>['eenie','meenie','minie'],
                                 -default=>'meenie',
                                 -labels=>\%labels);

     _p_o_p_u_p__m_e_n_u() creates a menu.

     1.      The required first argument is the menu's name (-name).

     2.      The required second argument (-values) is an array rrrreeeeffffeeeerrrreeeennnncccceeee
             containing the list of menu items in the menu.  You can pass the
             method an anonymous array, as shown in the example, or a



                                                                       PPPPaaaaggggeeee 22229999






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



             reference to a named array, such as "\@foo".

     3.      The optional third parameter (-default) is the name of the
             default menu choice.  If not specified, the first item will be
             the default.  The values of the previous choice will be
             maintained across queries.

     4.      The optional fourth parameter (-labels) is provided for people
             who want to use different values for the user-visible label
             inside the popup menu nd the value returned to your script.  It's
             a pointer to an associative array relating menu values to user-
             visible labels.  If you leave this parameter blank, the menu
             values will be displayed by default.  (You can also leave a label
             undefined if you want to).

             When the form is processed, the selected value of the popup menu
             can be retrieved using:

                   $popup_menu_value = $query->param('menu_name');

             JAVASCRIPTING: _p_o_p_u_p__m_e_n_u() recognizes the following event
             handlers:  ----oooonnnnCCCChhhhaaaannnnggggeeee, ----oooonnnnFFFFooooccccuuuussss, ----oooonnnnMMMMoooouuuusssseeeeOOOOvvvveeeerrrr, ----oooonnnnMMMMoooouuuusssseeeeOOOOuuuutttt, and
             ----oooonnnnBBBBlllluuuurrrr.  See the _t_e_x_t_f_i_e_l_d() section for details on when these
             handlers are called.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA SSSSCCCCRRRROOOOLLLLLLLLIIIINNNNGGGG LLLLIIIISSSSTTTT

        print $query->scrolling_list('list_name',
                                     ['eenie','meenie','minie','moe'],
                                     ['eenie','moe'],5,'true');
           -or-

        print $query->scrolling_list('list_name',
                                     ['eenie','meenie','minie','moe'],
                                     ['eenie','moe'],5,'true',
                                     \%labels);

             -or-

        print $query->scrolling_list(-name=>'list_name',
                                     -values=>['eenie','meenie','minie','moe'],
                                     -default=>['eenie','moe'],
                                     -size=>5,
                                     -multiple=>'true',
                                     -labels=>\%labels);

     _s_c_r_o_l_l_i_n_g__l_i_s_t() creates a scrolling list.

     PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss::::






                                                                       PPPPaaaaggggeeee 33330000






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     1.      The first and second arguments are the list name (-name) and
             values (-values).  As in the popup menu, the second argument
             should be an array reference.

     2.      The optional third argument (-default) can be either a reference
             to a list containing the values to be selected by default, or can
             be a single value to select.  If this argument is missing or
             undefined, then nothing is selected when the list first appears.
             In the named parameter version, you can use the synonym
             "-defaults" for this parameter.

     3.      The optional fourth argument is the size of the list (-size).

     4.      The optional fifth argument can be set to true to allow multiple
             simultaneous selections (-multiple).  Otherwise only one
             selection will be allowed at a time.

     5.      The optional sixth argument is a pointer to an associative array
             containing long user-visible labels for the list items (-labels).
             If not provided, the values will be displayed.

             When this form is processed, all selected list items will be
             returned as a list under the parameter name 'list_name'.  The
             values of the selected items can be retrieved with:

                   @selected = $query->param('list_name');


             JAVASCRIPTING: _s_c_r_o_l_l_i_n_g__l_i_s_t() recognizes the following event
             handlers: ----oooonnnnCCCChhhhaaaannnnggggeeee, ----oooonnnnFFFFooooccccuuuussss, ----oooonnnnMMMMoooouuuusssseeeeOOOOvvvveeeerrrr, ----oooonnnnMMMMoooouuuusssseeeeOOOOuuuutttt and
             ----oooonnnnBBBBlllluuuurrrr.  See _t_e_x_t_f_i_e_l_d() for the description of when these
             handlers are called.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA GGGGRRRROOOOUUUUPPPP OOOOFFFF RRRREEEELLLLAAAATTTTEEEEDDDD CCCCHHHHEEEECCCCKKKKBBBBOOOOXXXXEEEESSSS

        print $query->checkbox_group(-name=>'group_name',
                                     -values=>['eenie','meenie','minie','moe'],
                                     -default=>['eenie','moe'],
                                     -linebreak=>'true',
                                     -labels=>\%labels);

        print $query->checkbox_group('group_name',
                                     ['eenie','meenie','minie','moe'],
                                     ['eenie','moe'],'true',\%labels);

        HTML3-COMPATIBLE BROWSERS ONLY:

        print $query->checkbox_group(-name=>'group_name',
                                     -values=>['eenie','meenie','minie','moe'],
                                     -rows=2,-columns=>2);





                                                                       PPPPaaaaggggeeee 33331111






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     _c_h_e_c_k_b_o_x__g_r_o_u_p() creates a list of checkboxes that are related by the
     same name.

     PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss::::

     1.      The first and second arguments are the checkbox name and values,
             respectively (-name and -values).  As in the popup menu, the
             second argument should be an array reference.  These values are
             used for the user-readable labels printed next to the checkboxes
             as well as for the values passed to your script in the query
             string.

     2.      The optional third argument (-default) can be either a reference
             to a list containing the values to be checked by default, or can
             be a single value to checked.  If this argument is missing or
             undefined, then nothing is selected when the list first appears.

     3.      The optional fourth argument (-linebreak) can be set to true to
             place line breaks between the checkboxes so that they appear as a
             vertical list.  Otherwise, they will be strung together on a
             horizontal line.

     4.      The optional fifth argument is a pointer to an associative array
             relating the checkbox values to the user-visible labels that will
             be printed next to them (-labels).  If not provided, the values
             will be used as the default.

     5.      HHHHTTTTMMMMLLLL3333----ccccoooommmmppppaaaattttiiiibbbblllleeee bbbbrrrroooowwwwsssseeeerrrrssss (such as Netscape) can take advantage
             of the optional parameters ----rrrroooowwwwssss, and ----ccccoooolllluuuummmmnnnnssss.  These parameters
             cause _c_h_e_c_k_b_o_x__g_r_o_u_p() to return an HTML3 compatible table
             containing the checkbox group formatted with the specified number
             of rows and columns.  You can provide just the -columns parameter
             if you wish; checkbox_group will calculate the correct number of
             rows for you.

             To include row and column headings in the returned table, you can
             use the ----rrrroooowwwwhhhheeeeaaaaddddeeeerrrrssss and ----ccccoooollllhhhheeeeaaaaddddeeeerrrrssss parameters.  Both of these
             accept a pointer to an array of headings to use.  The headings
             are just decorative.  They don't reorganize the interpretation of
             the checkboxes -- they're still a single named unit.

             When the form is processed, all checked boxes will be returned as
             a list under the parameter name 'group_name'.  The values of the
             "on" checkboxes can be retrieved with:

                   @turned_on = $query->param('group_name');

             The value returned by _c_h_e_c_k_b_o_x__g_r_o_u_p() is actually an array of
             button elements.  You can capture them and use them within
             tables, lists, or in other creative ways:





                                                                       PPPPaaaaggggeeee 33332222






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



                 @h = $query->checkbox_group(-name=>'group_name',-values=>\@values);
                 &use_in_creative_way(@h);

             JAVASCRIPTING: _c_h_e_c_k_b_o_x__g_r_o_u_p() recognizes the ----oooonnnnCCCClllliiiicccckkkk
             parameter.  This specifies a JavaScript code fragment or function
             call to be executed every time the user clicks on any of the
             buttons in the group.  You can retrieve the identity of the
             particular button clicked on using the "this" variable.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA SSSSTTTTAAAANNNNDDDDAAAALLLLOOOONNNNEEEE CCCCHHHHEEEECCCCKKKKBBBBOOOOXXXX

         print $query->checkbox(-name=>'checkbox_name',
                                -checked=>'checked',
                                -value=>'ON',
                                -label=>'CLICK ME');

             -or-

         print $query->checkbox('checkbox_name','checked','ON','CLICK ME');

     _c_h_e_c_k_b_o_x() is used to create an isolated checkbox that isn't logically
     related to any others.

     PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss::::

     1.      The first parameter is the required name for the checkbox
             (-name).  It will also be used for the user-readable label
             printed next to the checkbox.

     2.      The optional second parameter (-checked) specifies that the
             checkbox is turned on by default.  Synonyms are -selected and
             -on.

     3.      The optional third parameter (-value) specifies the value of the
             checkbox when it is checked.  If not provided, the word "on" is
             assumed.

     4.      The optional fourth parameter (-label) is the user-readable label
             to be attached to the checkbox.  If not provided, the checkbox
             name is used.

             The value of the checkbox can be retrieved using:

                 $turned_on = $query->param('checkbox_name');

             JAVASCRIPTING: _c_h_e_c_k_b_o_x() recognizes the ----oooonnnnCCCClllliiiicccckkkk parameter.  See
             _c_h_e_c_k_b_o_x__g_r_o_u_p() for further details.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA RRRRAAAADDDDIIIIOOOO BBBBUUUUTTTTTTTTOOOONNNN GGGGRRRROOOOUUUUPPPP






                                                                       PPPPaaaaggggeeee 33333333






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



        print $query->radio_group(-name=>'group_name',
                                  -values=>['eenie','meenie','minie'],
                                  -default=>'meenie',
                                  -linebreak=>'true',
                                  -labels=>\%labels);

             -or-

        print $query->radio_group('group_name',['eenie','meenie','minie'],
                                               'meenie','true',\%labels);

        HTML3-COMPATIBLE BROWSERS ONLY:

        print $query->radio_group(-name=>'group_name',
                                  -values=>['eenie','meenie','minie','moe'],
                                  -rows=2,-columns=>2);

     _r_a_d_i_o__g_r_o_u_p() creates a set of logically-related radio buttons (turning
     one member of the group on turns the others off)

     PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss::::

     1.      The first argument is the name of the group and is required
             (-name).

     2.      The second argument (-values) is the list of values for the radio
             buttons.  The values and the labels that appear on the page are
             identical.  Pass an array _r_e_f_e_r_e_n_c_e in the second argument,
             either using an anonymous array, as shown, or by referencing a
             named array as in "\@foo".

     3.      The optional third parameter (-default) is the name of the
             default button to turn on. If not specified, the first item will
             be the default.  You can provide a nonexistent button name, such
             as "-" to start up with no buttons selected.

     4.      The optional fourth parameter (-linebreak) can be set to 'true'
             to put line breaks between the buttons, creating a vertical list.

     5.      The optional fifth parameter (-labels) is a pointer to an
             associative array relating the radio button values to user-
             visible labels to be used in the display.  If not provided, the
             values themselves are displayed.

     6.      HHHHTTTTMMMMLLLL3333----ccccoooommmmppppaaaattttiiiibbbblllleeee bbbbrrrroooowwwwsssseeeerrrrssss (such as Netscape) can take advantage
             of the optional parameters ----rrrroooowwwwssss, and ----ccccoooolllluuuummmmnnnnssss.  These parameters
             cause _r_a_d_i_o__g_r_o_u_p() to return an HTML3 compatible table
             containing the radio group formatted with the specified number of
             rows and columns.  You can provide just the -columns parameter if
             you wish; radio_group will calculate the correct number of rows
             for you.




                                                                       PPPPaaaaggggeeee 33334444






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



             To include row and column headings in the returned table, you can
             use the ----rrrroooowwwwhhhheeeeaaaaddddeeeerrrr and ----ccccoooollllhhhheeeeaaaaddddeeeerrrr parameters.  Both of these
             accept a pointer to an array of headings to use.  The headings
             are just decorative.  They don't reorganize the interpetation of
             the radio buttons -- they're still a single named unit.

             When the form is processed, the selected radio button can be
             retrieved using:

                   $which_radio_button = $query->param('group_name');

             The value returned by _r_a_d_i_o__g_r_o_u_p() is actually an array of
             button elements.  You can capture them and use them within
             tables, lists, or in other creative ways:

                 @h = $query->radio_group(-name=>'group_name',-values=>\@values);
                 &use_in_creative_way(@h);


     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA SSSSUUUUBBBBMMMMIIIITTTT BBBBUUUUTTTTTTTTOOOONNNN

        print $query->submit(-name=>'button_name',
                             -value=>'value');

             -or-

        print $query->submit('button_name','value');

     _s_u_b_m_i_t() will create the query submission button.  Every form should have
     one of these.

     PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss::::

     1.      The first argument (-name) is optional.  You can give the button
             a name if you have several submission buttons in your form and
             you want to distinguish between them.  The name will also be used
             as the user-visible label.  Be aware that a few older browsers
             don't deal with this correctly and nnnneeeevvvveeeerrrr send back a value from a
             button.

     2.      The second argument (-value) is also optional.  This gives the
             button a value that will be passed to your script in the query
             string.

             You can figure out which button was pressed by using different
             values for each one:

                  $which_one = $query->param('button_name');

             JAVASCRIPTING: _r_a_d_i_o__g_r_o_u_p() recognizes the ----oooonnnnCCCClllliiiicccckkkk parameter.
             See _c_h_e_c_k_b_o_x__g_r_o_u_p() for further details.




                                                                       PPPPaaaaggggeeee 33335555






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA RRRREEEESSSSEEEETTTT BBBBUUUUTTTTTTTTOOOONNNN

        print $query->reset

     _r_e_s_e_t() creates the "reset" button.  Note that it restores the form to
     its value from the last time the script was called, NOT necessarily to
     the defaults.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA DDDDEEEEFFFFAAAAUUUULLLLTTTT BBBBUUUUTTTTTTTTOOOONNNN

        print $query->defaults('button_label')

     _d_e_f_a_u_l_t_s() creates a button that, when invoked, will cause the form to be
     completely reset to its defaults, wiping out all the changes the user
     ever made.

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA HHHHIIIIDDDDDDDDEEEENNNN FFFFIIIIEEEELLLLDDDD

             print $query->hidden(-name=>'hidden_name',
                                  -default=>['value1','value2'...]);

                     -or-

             print $query->hidden('hidden_name','value1','value2'...);

     _h_i_d_d_e_n() produces a text field that can't be seen by the user.  It is
     useful for passing state variable information from one invocation of the
     script to the next.

     PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss::::

     1.      The first argument is required and specifies the name of this
             field (-name).

     2.      The second argument is also required and specifies its value
             (-default).  In the named parameter style of calling, you can
             provide a single value here or a reference to a whole list

             Fetch the value of a hidden field this way:

                  $hidden_value = $query->param('hidden_name');

             Note, that just like all the other form elements, the value of a
             hidden field is "sticky".  If you want to replace a hidden field
             with some other values after the script has been called once
             you'll have to do it manually:

                  $query->param('hidden_name','new','values','here');







                                                                       PPPPaaaaggggeeee 33336666






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA CCCCLLLLIIIICCCCKKKKAAAABBBBLLLLEEEE IIIIMMMMAAAAGGGGEEEE BBBBUUUUTTTTTTTTOOOONNNN

          print $query->image_button(-name=>'button_name',
                                     -src=>'/source/URL',
                                     -align=>'MIDDLE');

             -or-

          print $query->image_button('button_name','/source/URL','MIDDLE');

     _i_m_a_g_e__b_u_t_t_o_n() produces a clickable image.  When it's clicked on the
     position of the click is returned to your script as "button_name.x" and
     "button_name.y", where "button_name" is the name you've assigned to it.

     JAVASCRIPTING: _i_m_a_g_e__b_u_t_t_o_n() recognizes the ----oooonnnnCCCClllliiiicccckkkk parameter.  See
     _c_h_e_c_k_b_o_x__g_r_o_u_p() for further details.

     PPPPaaaarrrraaaammmmeeeetttteeeerrrrssss::::

     1.      The first argument (-name) is required and specifies the name of
             this field.

     2.      The second argument (-src) is also required and specifies the URL

BOTTOM or MIDDLE
     3. The third option (-align, optional) is an alignment type, and may be TOP,

             Fetch the value of the button this way:
                  $x = $query->_p_a_r_a_m('button_name.x');
                  $y = $query->_p_a_r_a_m('button_name.y');

     CCCCRRRREEEEAAAATTTTIIIINNNNGGGG AAAA JJJJAAAAVVVVAAAASSSSCCCCRRRRIIIIPPPPTTTT AAAACCCCTTTTIIIIOOOONNNN BBBBUUUUTTTTTTTTOOOONNNN

          print $query->button(-name=>'button_name',
                               -value=>'user visible label',
                               -onClick=>"do_something()");

             -or-

          print $query->button('button_name',"do_something()");

     _b_u_t_t_o_n() produces a button that is compatible with Netscape 2.0's
     JavaScript.  When it's pressed the fragment of JavaScript code pointed to
     by the ----oooonnnnCCCClllliiiicccckkkk parameter will be executed.  On non-Netscape browsers
     this form element will probably not even display.

NNNNEEEETTTTSSSSCCCCAAAAPPPPEEEE CCCCOOOOOOOOKKKKIIIIEEEESSSS
     Netscape browsers versions 1.1 and higher support a so-called "cookie"
     designed to help maintain state within a browser session.  CGI.pm has
     several methods that support cookies.

     A cookie is a name=value pair much like the named parameters in a CGI



                                                                       PPPPaaaaggggeeee 33337777






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     query string.  CGI scripts create one or more cookies and send them to
     the browser in the HTTP header.  The browser maintains a list of cookies
     that belong to a particular Web server, and returns them to the CGI
     script during subsequent interactions.

     In addition to the required name=value pair, each cookie has several
     optional attributes:

     1. an expiration time
             This is a time/date string (in a special GMT format) that
             indicates when a cookie expires.  The cookie will be saved and
             returned to your script until this expiration date is reached if
             the user exits Netscape and restarts it.  If an expiration date
             isn't specified, the cookie will remain active until the user
             quits Netscape.

     2. a domain
             This is a partial or complete domain name for which the cookie is
             valid.  The browser will return the cookie to any host that
             matches the partial domain name.  For example, if you specify a
             domain name of ".capricorn.com", then Netscape will return the
             cookie to Web servers running on any of the machines
             "www.capricorn.com", "www2.capricorn.com",
             "feckless.capricorn.com", etc.  Domain names must contain at
             least two periods to prevent attempts to match on top level
             domains like ".edu".  If no domain is specified, then the browser
             will only return the cookie to servers on the host the cookie
             originated from.

     3. a path
             If you provide a cookie path attribute, the browser will check it
             against your script's URL before returning the cookie.  For
             example, if you specify the path "/cgi-bin", then the cookie will
             be returned to each of the scripts "/cgi-bin/tally.pl", "/cgi-
             bin/order.pl", and "/cgi-bin/customer_service/complain.pl", but
             not to the script "/cgi-private/site_admin.pl".  By default, path
             is set to "/", which causes the cookie to be sent to any CGI
             script on your site.

     4. a "secure" flag
             If the "secure" attribute is set, the cookie will only be sent to
             your script if the CGI request is occurring on a secure channel,
             such as SSL.

             The interface to Netscape cookies is the ccccooooooookkkkiiiieeee(((()))) method:










                                                                       PPPPaaaaggggeeee 33338888






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



                 $cookie = $query->cookie(-name=>'sessionID',
                                          -value=>'xyzzy',
                                          -expires=>'+1h',
                                          -path=>'/cgi-bin/database',
                                          -domain=>'.capricorn.org',
                                          -secure=>1);
                 print $query->header(-cookie=>$cookie);

             ccccooooooookkkkiiiieeee(((()))) creates a new cookie.  Its parameters include:

     ----nnnnaaaammmmeeee   The name of the cookie (required).  This can be any string at
             all.  Although Netscape limits its cookie names to non-whitespace
             alphanumeric characters, CGI.pm removes this restriction by
             escaping and unescaping cookies behind the scenes.

     ----vvvvaaaalllluuuueeee  The value of the cookie.  This can be any scalar value, array
             reference, or even associative array reference.  For example, you
             can store an entire associative array into a cookie this way:

                     $cookie=$query->cookie(-name=>'family information',
                                            -value=>\%childrens_ages);


     ----ppppaaaatttthhhh   The optional partial path for which this cookie will be valid, as
             described above.

     ----ddddoooommmmaaaaiiiinnnn The optional partial domain for which this cookie will be valid,
             as described above.

     ----eeeexxxxppppiiiirrrreeeessss
             The optional expiration date for this cookie.  The format is as
             described in the section on the hhhheeeeaaaaddddeeeerrrr(((()))) method:

                     "+1h"  one hour from now


     ----sssseeeeccccuuuurrrreeee If set to true, this cookie will only be used within a secure SSL
             session.

             The cookie created by _c_o_o_k_i_e() must be incorporated into the HTTP
             header within the string returned by the _h_e_a_d_e_r() method:

                     print $query->header(-cookie=>$my_cookie);

             To create multiple cookies, give _h_e_a_d_e_r() an array reference:

                     $cookie1 = $query->cookie(-name=>'riddle_name',
                                               -value=>"The Sphynx's Question");
                     $cookie2 = $query->cookie(-name=>'answers',
                                               -value=>\%answers);
                     print $query->header(-cookie=>[$cookie1,$cookie2]);




                                                                       PPPPaaaaggggeeee 33339999






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



             To retrieve a cookie, request it by name by calling _c_o_o_k_i_e()
             method without the ----vvvvaaaalllluuuueeee parameter:

                     use CGI;
                     $query = new CGI;
                     %answers = $query->cookie(-name=>'answers');
                     # $query->cookie('answers') will work too!

             The cookie and CGI namespaces are separate.  If you have a
             parameter named 'answers' and a cookie named 'answers', the
             values retrieved by _p_a_r_a_m() and _c_o_o_k_i_e() are independent of each
             other.  However, it's simple to turn a CGI parameter into a
             cookie, and vice-versa:

                # turn a CGI parameter into a cookie
                $c=$q->cookie(-name=>'answers',-value=>[$q->param('answers')]);
                # vice-versa
                $q->param(-name=>'answers',-value=>[$q->cookie('answers')]);

             See the ccccooooooookkkkiiiieeee....ccccggggiiii example script for some ideas on how to use
             cookies effectively.

             NNNNOOOOTTTTEEEE:::: There appear to be some (undocumented) restrictions on
             Netscape cookies.  In Netscape 2.01, at least, I haven't been
             able to set more than three cookies at a time.  There may also be
             limits on the length of cookies.  If you need to store a lot of
             information, it's probably better to create a unique session ID,
             store it in a cookie, and use the session ID to locate an
             external file/database saved on the server's side of the
             connection.

WWWWOOOORRRRKKKKIIIINNNNGGGG WWWWIIIITTTTHHHH NNNNEEEETTTTSSSSCCCCAAAAPPPPEEEE FFFFRRRRAAAAMMMMEEEESSSS
     It's possible for CGI.pm scripts to write into several browser panels and
     windows using Netscape's frame mechanism. There are three techniques for
     defining new frames programmatically:

     1. Create a <Frameset> document
             After writing out the HTTP header, instead of creating a standard
             HTML document using the _s_t_a_r_t__h_t_m_l() call, create a <FRAMESET>
             document that defines the frames on the page.  Specify your
             _s_c_r_i_p_t(s) (with appropriate parameters) as the SRC for each of
             the frames.

             There is no specific support for creating <FRAMESET> sections in
             CGI.pm, but the HTML is very simple to write.  See the frame
             documentation in Netscape's home pages for details

               http://home.netscape.com/assist/net_sites/frames.html







                                                                       PPPPaaaaggggeeee 44440000






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     2. Specify the destination for the document in the HTTP header
             You may provide a ----ttttaaaarrrrggggeeeetttt parameter to the _h_e_a_d_e_r() method:

                 print $q->_h_e_a_d_e_r(-target=>'ResultsWindow');

             This will tell Netscape to load the output of your script into
             the frame named "ResultsWindow".  If a frame of that name doesn't
             already exist, Netscape will pop up a new window and load your
             script's document into that.  There are a number of magic names
             that you can use for targets.  See the frame documents on
             Netscape's home pages for details.

     3. Specify the destination for the document in the <FORM> tag
             You can specify the frame to load in the FORM tag itself.  With
             CGI.pm it looks like this:

                 print $q->startform(-target=>'ResultsWindow');

             When your script is reinvoked by the form, its output will be
             loaded into the frame named "ResultsWindow".  If one doesn't
             already exist a new window will be created.

             The script "frameset.cgi" in the examples directory shows one way
             to create pages in which the fill-out form and the response live
             in side-by-side frames.

LLLLIIIIMMMMIIIITTTTEEEEDDDD SSSSUUUUPPPPPPPPOOOORRRRTTTT FFFFOOOORRRR CCCCAAAASSSSCCCCAAAADDDDIIIINNNNGGGG SSSSTTTTYYYYLLLLEEEE SSSSHHHHEEEEEEEETTTTSSSS
     CGI.pm has limited support for HTML3's cascading style sheets (css).  To
     incorporate a stylesheet into your document, pass the _s_t_a_r_t__h_t_m_l() method
     a ----ssssttttyyyylllleeee parameter.  The value of this parameter may be a scalar, in
     which case it is incorporated directly into a <STYLE> section, or it may
     be a hash reference.  In the latter case you should provide the hash with
     one or more of ----ssssrrrrcccc or ----ccccooooddddeeee.  ----ssssrrrrcccc points to a URL where an externally-
     defined stylesheet can be found.  ----ccccooooddddeeee points to a scalar value to be
     incorporated into a <STYLE> section.  Style definitions in ----ccccooooddddeeee override
     similarly-named ones in ----ssssrrrrcccc, hence the name "cascading."

     You may also specify the type of the stylesheet by adding the optional
     ----ttttyyyyppppeeee parameter to the hash pointed to by ----ssssttttyyyylllleeee.  If not specified, the
     style defaults to 'text/css'.

     To refer to a style within the body of your document, add the ----ccccllllaaaassssssss
     parameter to any HTML element:

         print h1({-class=>'Fancy'},'Welcome to the Party');

     Or define styles on the fly with the ----ssssttttyyyylllleeee parameter:

         print h1({-style=>'Color: red;'},'Welcome to Hell');

     You may also use the new ssssppppaaaannnn(((()))) element to apply a style to a section of
     text:



                                                                       PPPPaaaaggggeeee 44441111






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



         print span({-style=>'Color: red;'},
                    h1('Welcome to Hell'),
                    "Where did that handbasket get to?"
                    );

     Note that you must import the ":html3" definitions to have the ssssppppaaaannnn(((())))
     method available.  Here's a quick and dirty example of using CSS's.  See
     the CSS specification at http://www.w3.org/pub/WWW/TR/Wd-css-1.html for
     more information.

         use CGI qw/:standard :html3/;

         #here's a stylesheet incorporated directly into the page
         $newStyle=<<END;
         <!--
         P.Tip {
             margin-right: 50pt;
             margin-left: 50pt;
             color: red;
         }
         P.Alert {
             font-size: 30pt;
             font-family: sans-serif;
           color: red;
         }
         -->
         END
         print header();
         print start_html( -title=>'CGI with Style',
                           -style=>{-src=>'http://www.capricorn.com/style/st1.css',
                                    -code=>$newStyle}
                          );
         print h1('CGI with Style'),
               p({-class=>'Tip'},
                 "Better read the cascading style sheet spec before playing with this!"),
               span({-style=>'color: magenta'},
                    "Look Mom, no hands!",
                    p(),
                    "Whooo wee!"
                    );
         print end_html;


DDDDEEEEBBBBUUUUGGGGGGGGIIIINNNNGGGG
     If you are running the script from the command line or in the perl
     debugger, you can pass the script a list of keywords or parameter=value
     pairs on the command line or from standard input (you don't have to worry
     about tricking your script into reading from environment variables).  You
     can pass keywords like this:

         your_script.pl keyword1 keyword2 keyword3




                                                                       PPPPaaaaggggeeee 44442222






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     or this:

        your_script.pl keyword1+keyword2+keyword3

     or this:

         your_script.pl name1=value1 name2=value2

     or this:

         your_script.pl name1=value1&name2=value2

     or even as newline-delimited parameters on standard input.

     When debugging, you can use quotes and backslashes to escape characters
     in the familiar shell manner, letting you place spaces and other funny
     characters in your parameter=value pairs:

        your_script.pl "name1='I am a long value'" "name2=two\ words"


     DDDDUUUUMMMMPPPPIIIINNNNGGGG OOOOUUUUTTTT AAAALLLLLLLL TTTTHHHHEEEE NNNNAAAAMMMMEEEE////VVVVAAAALLLLUUUUEEEE PPPPAAAAIIIIRRRRSSSS

     The _d_u_m_p() method produces a string consisting of all the query's
     name/value pairs formatted nicely as a nested list.  This is useful for
     debugging purposes:

         print $query->dump


     Produces something that looks like:

         <UL>
         <LI>name1
             <UL>
             <LI>value1
             <LI>value2
             </UL>
         <LI>name2
             <UL>
             <LI>value1
             </UL>
         </UL>

     You can pass a value of 'true' to _d_u_m_p() in order to get it to print the
     results out as plain text, suitable for incorporating into a <PRE>
     section.

     As a shortcut, as of version 1.56 you can interpolate the entire CGI
     object into a string and it will be replaced with the a nice HTML dump
     shown above:




                                                                       PPPPaaaaggggeeee 44443333






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



         $query=new CGI;
         print "<H2>Current Values</H2> $query\n";


FFFFEEEETTTTCCCCHHHHIIIINNNNGGGG EEEENNNNVVVVIIIIRRRROOOONNNNMMMMEEEENNNNTTTT VVVVAAAARRRRIIIIAAAABBBBLLLLEEEESSSS
     Some of the more useful environment variables can be fetched through this
     interface.  The methods are as follows:

     aaaacccccccceeeepppptttt(((())))
             Return a list of MIME types that the remote browser accepts. If
             you give this method a single argument corresponding to a MIME
             type, as in $query->_a_c_c_e_p_t('text/html'), it will return a
             floating point value corresponding to the browser's preference
             for this type from 0.0 (don't want) to 1.0.  Glob types (e.g.
             text/*) in the browser's accept list are handled correctly.

     rrrraaaawwww____ccccooooooookkkkiiiieeee(((())))
             Returns the HTTP_COOKIE variable, an HTTP extension implemented
             by Netscape browsers version 1.1 and higher.  Cookies have a
             special format, and this method call just returns the raw form
             (?cookie dough).  See _c_o_o_k_i_e() for ways of setting and retrieving
             cooked cookies.

             Called with no parameters, _r_a_w__c_o_o_k_i_e() returns the packed cookie
             structure.  You can separate it into individual cookies by
             splitting on the character sequence "; ".  Called with the name
             of a cookie, retrieves the uuuunnnneeeessssccccaaaappppeeeedddd form of the cookie.  You can
             use the regular _c_o_o_k_i_e() method to get the names, or use the
             _r_a_w__f_e_t_c_h() method from the CGI::Cookie module.

     uuuusssseeeerrrr____aaaaggggeeeennnntttt(((())))
             Returns the HTTP_USER_AGENT variable.  If you give this method a
             single argument, it will attempt to pattern match on it, allowing
             you to do something like $query->_u_s_e_r__a_g_e_n_t(netscape);

     ppppaaaatttthhhh____iiiinnnnffffoooo(((())))
             Returns additional path information from the script URL.  E.G.
             fetching /cgi-bin/your_script/additional/stuff will result in
             $query->_p_a_t_h__i_n_f_o() returning "additional/stuff".

             NOTE: The Microsoft Internet Information Server is broken with
             respect to additional path information.  If you use the Perl DLL
             library, the IIS server will attempt to execute the additional
             path information as a Perl script.  If you use the ordinary file
             associations mapping, the path information will be present in the
             environment, but incorrect.  The best thing to do is to avoid
             using additional path information in CGI scripts destined for use
             with IIS.

     ppppaaaatttthhhh____ttttrrrraaaannnnssssllllaaaatttteeeedddd(((())))
             As per _p_a_t_h__i_n_f_o() but returns the additional path information
             translated into a physical path, e.g.



                                                                       PPPPaaaaggggeeee 44444444






CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



             "/usr/local/etc/httpd/htdocs/additional/stuff".

             The Microsoft IIS is broken with respect to the translated path
             as well.

     rrrreeeemmmmooootttteeee____hhhhoooosssstttt(((())))
             Returns either the remote host name or IP address.  if the former
             is unavailable.

scripts.
     ssssccccrrrriiiipppptttt____nnnnaaaammmmeeee(((()))) Return the script name as a partial URL, for self-refering

     rrrreeeeffffeeeerrrreeeerrrr(((())))
             Return the URL of the page the browser was viewing prior to
             fetching your script.  Not available for all browsers.

     aaaauuuutttthhhh____ttttyyyyppppeeee (((())))
             Return the authorization/verification method in use for this
             script, if any.

     sssseeeerrrrvvvveeeerrrr____nnnnaaaammmmeeee (((())))
             Returns the name of the server, usually the machine's host name.

     vvvviiiirrrrttttuuuuaaaallll____hhhhoooosssstttt (((())))
             When using virtual hosts, returns the name of the host that the
             browser attempted to contact

     sssseeeerrrrvvvveeeerrrr____ssssooooffffttttwwwwaaaarrrreeee (((())))
             Returns the server software and version number.

     rrrreeeemmmmooootttteeee____uuuusssseeeerrrr (((())))
             Return the authorization/verification name used for user
             verification, if this script is protected.

     uuuusssseeeerrrr____nnnnaaaammmmeeee (((())))
             Attempt to obtain the remote user's name, using a variety of
             different techniques.  This only works with older browsers such
             as Mosaic.  Netscape does not reliably report the user name!

     rrrreeeeqqqquuuueeeesssstttt____mmmmeeeetttthhhhoooodddd(((())))
             Returns the method used to access your script, usually one of
             'POST', 'GET' or 'HEAD'.

UUUUSSSSIIIINNNNGGGG NNNNPPPPHHHH SSSSCCCCRRRRIIIIPPPPTTTTSSSS
     NPH, or "no-parsed-header", scripts bypass the server completely by
     sending the complete HTTP header directly to the browser.  This has
     slight performance benefits, but is of most use for taking advantage of
     HTTP extensions that are not directly supported by your server, such as
     server push and PICS headers.

     Servers use a variety of conventions for designating CGI scripts as NPH.
     Many Unix servers look at the beginning of the script's name for the



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CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     prefix "nph-".  The Macintosh WebSTAR server and Microsoft's Internet
     Information Server, in contrast, try to decide whether a program is an
     NPH script by examining the first line of script output.

     CGI.pm supports NPH scripts with a special NPH mode.  When in this mode,
     CGI.pm will output the necessary extra header information when the
     _h_e_a_d_e_r() and _r_e_d_i_r_e_c_t() methods are called.

     The Microsoft Internet Information Server requires NPH mode.  As of
     version 2.30, CGI.pm will automatically detect when the script is running
     under IIS and put itself into this mode.  You do not need to do this
     manually, although it won't hurt anything if you do.

     There are a number of ways to put CGI.pm into NPH mode:

     In the uuuusssseeee statement
             Simply add the "-nph" pragmato the list of symbols to be imported
             into your script:

                   use CGI qw(:standard -nph)


     By calling the nnnnpppphhhh(((()))) method:
             Call nnnnpppphhhh(((()))) with a non-zero parameter at any point after using
             CGI.pm in your program.

                   CGI->nph(1)


     By using ----nnnnpppphhhh parameters in the hhhheeeeaaaaddddeeeerrrr(((()))) and rrrreeeeddddiiiirrrreeeecccctttt(((())))  statements:

                   print $q->header(-nph=>1);


SSSSeeeerrrrvvvveeeerrrr PPPPuuuusssshhhh
     CGI.pm provides three simple functions for producing multipart documents
     of the type needed to implement server push.  These functions were
     graciously provided by Ed Jordan <[e-mail]>.  To import these into
     your namespace, you must import the ":push" set.  You are also advised to
     put the script into NPH mode and to set $| to 1 to avoid buffering
     problems.

     Here is a simple script that demonstrates server push:












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       #!/usr/local/bin/perl
       use CGI qw/:push -nph/;
       $| = 1;
       print multipart_init(-boundary=>'----------------here we go!');
       while (1) {
           print multipart_start(-type=>'text/plain'),
                 "The current time is ",scalar(localtime),"\n",
                 multipart_end;
           sleep 1;
       }

     This script initializes server push by calling mmmmuuuullllttttiiiippppaaaarrrrtttt____iiiinnnniiiitttt(((()))).  It then
     enters an infinite loop in which it begins a new multipart section by
     calling mmmmuuuullllttttiiiippppaaaarrrrtttt____ssssttttaaaarrrrtttt(((()))), prints the current local time, and ends a
     multipart section with mmmmuuuullllttttiiiippppaaaarrrrtttt____eeeennnndddd(((()))).  It then sleeps a second, and
     begins again.

     multipart_init()         multipart_init(-boundary=>$boundary);
             Initialize the multipart system.  The -boundary argument
             specifies what MIME boundary string to use to separate parts of
             the document.  If not provided, CGI.pm chooses a reasonable
             boundary for you.

     multipart_start()

               multipart_start(-type=>$type)

             Start a new part of the multipart document using the specified
             MIME type.  If not specified, text/html is assumed.

     multipart_end()

               multipart_end()

             End a part.  You must remember to call _m_u_l_t_i_p_a_r_t__e_n_d() once for
             each _m_u_l_t_i_p_a_r_t__s_t_a_r_t().

             Users interested in server push applications should also have a
             look at the CGI::Push module.

AAAAvvvvooooiiiiddddiiiinnnngggg DDDDeeeennnniiiiaaaallll ooooffff SSSSeeeerrrrvvvviiiicccceeee AAAAttttttttaaaacccckkkkssss
     A potential problem with CGI.pm is that, by default, it attempts to
     process form POSTings no matter how large they are.  A wily hacker could
     attack your site by sending a CGI script a huge POST of many megabytes.
     CGI.pm will attempt to read the entire POST into a variable, growing
     hugely in size until it runs out of memory.  While the script attempts to
     allocate the memory the system may slow down dramatically.  This is a
     form of denial of service attack.

     Another possible attack is for the remote user to force CGI.pm to accept
     a huge file upload.  CGI.pm will accept the upload and store it in a
     temporary directory even if your script doesn't expect to receive an



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     uploaded file.  CGI.pm will delete the file automatically when it
     terminates, but in the meantime the remote user may have filled up the
     server's disk space, causing problems for other programs.

     The best way to avoid denial of service attacks is to limit the amount of
     memory, CPU time and disk space that CGI scripts can use.  Some Web
     servers come with built-in facilities to accomplish this. In other cases,
     you can use the shell _l_i_m_i_t or _u_l_i_m_i_t commands to put ceilings on CGI
     resource usage.

     CGI.pm also has some simple built-in protections against denial of
     service attacks, but you must activate them before you can use them.
     These take the form of two global variables in the CGI name space:

     $$$$CCCCGGGGIIII::::::::PPPPOOOOSSSSTTTT____MMMMAAAAXXXX
             If set to a non-negative integer, this variable puts a ceiling on
             the size of POSTings, in bytes.  If CGI.pm detects a POST that is
             greater than the ceiling, it will immediately exit with an error
             message.  This value will affect both ordinary POSTs and
             multipart POSTs, meaning that it limits the maximum size of file
             uploads as well.  You should set this to a reasonably high value,
             such as 1 megabyte.

     $$$$CCCCGGGGIIII::::::::DDDDIIIISSSSAAAABBBBLLLLEEEE____UUUUPPPPLLLLOOOOAAAADDDDSSSS
             If set to a non-zero value, this will disable file uploads
             completely.  Other fill-out form values will work as usual.

             You can use these variables in either of two ways.

     1111.... OOOOnnnn aaaa ssssccccrrrriiiipppptttt----bbbbyyyy----ssssccccrrrriiiipppptttt bbbbaaaassssiiiissss
             Set the variable at the top of the script, right after the "use"
             statement:

                 use CGI qw/:standard/;
                 use CGI::Carp 'fatalsToBrowser';
                 $CGI::POST_MAX=1024 * 100;  # max 100K posts
                 $CGI::DISABLE_UPLOADS = 1;  # no uploads


     2222.... GGGGlllloooobbbbaaaallllllllyyyy ffffoooorrrr aaaallllllll ssssccccrrrriiiippppttttssss
             Open up CGI.pm, find the definitions for $POST_MAX and
             $DISABLE_UPLOADS, and set them to the desired values.  You'll
             find them towards the top of the file in a subroutine named
             _i_n_i_t_i_a_l_i_z_e__g_l_o_b_a_l_s().

             Since an attempt to send a POST larger than $POST_MAX bytes will
             cause a fatal error, you might want to use CGI::Carp to echo the
             fatal error message to the browser window as shown in the example
             above.  Otherwise the remote user will see only a generic
             "Internal Server" error message.  See the the _C_G_I::_C_a_r_p manpage
             manual page for more details.




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CCCCOOOOMMMMPPPPAAAATTTTIIIIBBBBIIIILLLLIIIITTTTYYYY WWWWIIIITTTTHHHH CCCCGGGGIIII----LLLLIIIIBBBB....PPPPLLLL
     To make it easier to port existing programs that use cgi-lib.pl the
     compatibility routine "ReadParse" is provided.  Porting is simple:

     OLD VERSION
         require "cgi-lib.pl";
         &ReadParse;
         print "The value of the antique is $in{antique}.\n";

     NEW VERSION
         use CGI;
         CGI::ReadParse
         print "The value of the antique is $in{antique}.\n";

     CGI.pm's _R_e_a_d_P_a_r_s_e() routine creates a tied variable named %in, which can
     be accessed to obtain the query variables.  Like ReadParse, you can also
     provide your own variable.  Infrequently used features of ReadParse, such
     as the creation of @in and $in variables, are not supported.

     Once you use ReadParse, you can retrieve the query object itself this
     way:

         $q = $in{CGI};
         print $q->textfield(-name=>'wow',
                             -value=>'does this really work?');

     This allows you to start using the more interesting features of CGI.pm
     without rewriting your old scripts from scratch.

AAAAUUUUTTTTHHHHOOOORRRR IIIINNNNFFFFOOOORRRRMMMMAAAATTTTIIIIOOOONNNN
     Copyright 1995-1997, Lincoln D. Stein.  All rights reserved.  It may be
     used and modified freely, but I do request that this copyright notice
     remain attached to the file.  You may modify this module as you wish, but
     if you redistribute a modified version, please attach a note listing the
     modifications you have made.

     Address bug reports and comments to:  [e-mail]

CCCCRRRREEEEDDDDIIIITTTTSSSS
     Thanks very much to:

     Matt Heffron ([e-mail])

     James Taylor ([e-mail])

     Scott Anguish <[e-mail]>

     Mike Jewell ([e-mail])

     Timothy Shimmin ([e-mail])





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CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



     Joergen Haegg ([e-mail])

     Laurent Delfosse ([e-mail])

     Richard Resnick ([e-mail])

     Craig Bishop ([e-mail])

     Tony Curtis ([e-mail])

     Tim Bunce ([e-mail])

     Tom Christiansen ([e-mail])

     Andreas Koenig ([e-mail])

     Tim MacKenzie ([e-mail])

     Kevin B. Hendricks ([e-mail])

     Stephen Dahmen ([e-mail])

     Ed Jordan ([e-mail])

     David Alan Pisoni ([e-mail])

     Doug MacEachern ([e-mail])

     Robin Houston ([e-mail])

     ...and many many more...
             for suggestions and bug fixes.

AAAA CCCCOOOOMMMMPPPPLLLLEEEETTTTEEEE EEEEXXXXAAAAMMMMPPPPLLLLEEEE OOOOFFFF AAAA SSSSIIIIMMMMPPPPLLLLEEEE FFFFOOOORRRRMMMM----BBBBAAAASSSSEEEEDDDD SSSSCCCCRRRRIIIIPPPPTTTT
             #!/usr/local/bin/perl

             use CGI;

             $query = new CGI;
















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CCCCGGGGIIII((((3333))))                                                                  CCCCGGGGIIII((((3333))))



             print $query->header;
             print $query->start_html("Example CGI.pm Form");
             print "<H1> Example CGI.pm Form</H1>\n";
             &print_prompt($query);
             &do_work($query);
             &print_tail;
             print $query->end_html;

             sub print_prompt {
                my($query) = @_;

                print $query->startform;
                print "<EM>What's your name?</EM><BR>";
                print $query->textfield('name');
                print $query->checkbox('Not my real name');

                print "<P><EM>Where can you find English Sparrows?</EM><BR>";
                print $query->checkbox_group(
                                      -name=>'Sparrow locations',
                                      -values=>[England,France,Spain,Asia,Hoboken],
                                      -linebreak=>'yes',
                                      -defaults=>[England,Asia]);

                print "<P><EM>How far can they fly?</EM><BR>",
                     $query->radio_group(
                             -name=>'how far',
                             -values=>['10 ft','1 mile','10 miles','real far'],
                             -default=>'1 mile');

                print "<P><EM>What's your favorite color?</EM>  ";
                print $query->popup_menu(-name=>'Color',
                                         -values=>['black','brown','red','yellow'],
                                         -default=>'red');

                print $query->hidden('Reference','Monty Python and the Holy Grail');

                print "<P><EM>What have you got there?</EM><BR>";
                print $query->scrolling_list(
                              -name=>'possessions',
                              -values=>['A Coconut','A Grail','An Icon',
                                        'A Sword','A Ticket'],
                              -size=>5,
                              -multiple=>'true');

                print "<P><EM>Any parting comments?</EM><BR>";
                print $query->textarea(-name=>'Comments',
                                       -rows=>10,
                                       -columns=>50);

                print "<P>",$query->reset;
                print $query->submit('Action','Shout');
                print $query->submit('Action','Scream');



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                print $query->endform;
                print "<HR>\n";
             }

             sub do_work {
                my($query) = @_;
                my(@values,$key);

                print "<H2>Here are the current settings in this form</H2>";

                foreach $key ($query->param) {
                   print "<STRONG>$key</STRONG> -> ";
                   @values = $query->param($key);
                   print join(", ",@values),"<BR>\n";
               }
             }

             sub print_tail {
                print <<END;
             <HR>
             <ADDRESS>Lincoln D. Stein</ADDRESS><BR>
             <A HREF="/">Home Page</A>
             END
             }


BBBBUUUUGGGGSSSS
     This module has grown large and monolithic.  Furthermore it's doing many
     things, such as handling URLs, parsing CGI input, writing HTML, etc.,
     that are also done in the LWP modules. It should be discarded in favor of
     the CGI::* modules, but somehow I continue to work on it.

     Note that the code is truly contorted in order to avoid spurious warnings
     when programs are run with the ----wwww switch.

SSSSEEEEEEEE AAAALLLLSSSSOOOO
     the _C_G_I::_C_a_r_p manpage, the _U_R_I::_U_R_L manpage, the _C_G_I::_R_e_q_u_e_s_t manpage,
     the _C_G_I::_M_i_n_i_S_v_r manpage, the _C_G_I::_B_a_s_e manpage, the _C_G_I::_F_o_r_m manpage,
     the _C_G_I::_A_p_a_c_h_e manpage, the _C_G_I::_S_w_i_t_c_h manpage, the _C_G_I::_P_u_s_h manpage,
     the _C_G_I::_F_a_s_t manpage















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