First you need to initialize an object

    use CGI::Simple;
    my $q = CGI::Simple->new;

It is traditional to call your object $q for query or perhaps $cgi.

Next you call methods on that object

    @names = $q->param();

Many methods are sensitive to the context in which you call them. In the example above the param() method returns a list of all the parameter names when called without any arguments.

When you call param('arg') with a single argument it assumes you want to get the value(s) associated with that argument (parameter). If you ask for an array it gives you an array of all the values associated with it's argument:

    @values = $q->param('foo');  # get all the values for 'foo'

whereas if you ask for a scalar like this:

    $value = $q->param('foo');   # get only the first value for 'foo'

then it returns only the first value (if more than one value for 'foo' exists).

In case you ased for a list it will return all the values preserving the order in which the values of the given key were passed in the request.

Most CGI::Simple routines accept several arguments, sometimes as many as 10 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.

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. header() happens to be one of these routines. In this case, the single argument is the document type.

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

Sometimes methods 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 param() method can be 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']);

Selecting which methods to load

Alternatively CGI::Simple::Standard provides a range of function sets you can import or you can just select exactly what you want. You do this using the familiar

    use CGI::Simple::Standard qw( :func_set  some_func);

notation. This will import the ':func_set' function set and the specific function 'some_func'.

To Autoload or not to Autoload, that is the question.

If you do not use autoload you must specify what functions to import. You can only use functions that you have imported. For comvenience functions are grouped into related sets. If you choose to import one or more ':func_set' you may have potential namespace collisions so check out the docs to see what gets imported. Using the ':all' tag is pretty slack but it is there if you want. Full details of the function sets are provided in the CGI::Simple::Standard docs

If you just want say the param and header methods just load these two.

    use CGI::Simple::Standard qw(param header);

Setting globals using the functional interface

    $CGI::Simple::DEBUG = 1;

You use exactly the same syntax when using CGI::Simple::Standard.

new() Creating a new query object

     $q = CGI::Simple->new;

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

If you provide a file handle to the new() method, it will read parameters from the file (or STDIN, or whatever).

Historically people were doing this way:

     open FH, "test.in" or die $!;
     $q = CGI::Simple->new(\*FH);

but this is the recommended way:

     open $fh, '<', "test.in" or die $!;
     $q = CGI::Simple->new($fh);

The file should be a series of newline delimited TAG=VALUE pairs. Conveniently, this type of file is created by the save() method (see below). Multiple records can be saved and restored. IO::File objects work fine.

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

    restore_parameters($fh);

In fact for all intents and purposes restore_parameters() is identical to new() Note that restore_parameters() does not exist in CGI::Simple itself so you can't use it.

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

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

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

    $q = CGI::Simple->new( 'dinosaur=barney&color=purple' );

or from a previously existing CGI::Simple object (this generates an identical clone including all global variable settings, etc that are stored in the object):

    $old_query = CGI::Simple->new;
    $new_query = CGI::Simple->new($old_query);

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

    $empty_query = CGI::Simple->new("");

       -or-

    $empty_query = CGI::Simple->new({});

keywords() Fetching a list of keywords from a query

    @keywords = $q->keywords;

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

param() Fetching the names of all parameters passed to your script

    @names = $q->param;

If the script was invoked with a parameter list (e.g. "name1=value1&name2=value2&name3=value3"), the param() method will return the parameter names as a list. If the script was invoked as an <ISINDEX> script and contains a string without ampersands (e.g. "value1+value2+value3") , there will be a single parameter named "keywords" containing the "+"-delimited keywords.

NOTE: 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).

param() Fetching the value or values of a simple named parameter

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

          -or-

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

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

If a value is not given in the query string, as in the queries "name1=&name2=" or "name1&name2", it will be returned by default as an empty string. If you set the global variable:

    $CGI::Simple::NO_UNDEF_PARAMS = 1;

Then value-less parameters will be ignored, and will not exist in the query object. If you try to access them via param you will get an undef return value.

param() Setting the values of a named parameter

    $q->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.

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

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

                  -or-

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

param() Retrieving non-application/x-www-form-urlencoded data

    my $data = $q->param( 'POSTDATA' );

                  -or-

    my $data = $q->param( 'PUTDATA' );

(If you don't know what the preceding means, don't worry about it. It only affects people trying to use CGI::Simple for REST webservices)

add_param() Setting the values of a named parameter

    $q->add_param('foo', 'new');
    $q->add_param('foo', [1,2,3,4,5]);
    $q->add_param( 'foo', 'bar', 'overwrite' );

The first argument is the parameter, the second the value or an array ref of values and the optional third argument sets overwrite mode. If the third argument is absent of false the values will be appended. If true the values will overwrite any existing ones

append() Appending values to a named parameter

   $q->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.

import_names() Importing all parameters into a namespace.

delete() Deleting a parameter completely

    $q->delete('foo');

This completely clears a parameter. If you are using the function call interface, use Delete() instead to avoid conflicts with Perl's built-in delete operator.

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

delete_all() Deleting all parameters

    $q->delete_all();

This clears the CGI::Simple object completely. For CGI.pm compatibility Delete_all() is provided however there is no reason to use this in the function call interface other than symmetry.

For CGI.pm compatibility Delete_all() is provided as an alias for delete_all however there is no reason to use this, even in the function call interface.

param_fetch() Direct access to the parameter list

Vars() Fetching the entire parameter list as a hash

    $params = $q->Vars;  # as a tied hash ref
    print $params->{'address'};
    @foo = split "\0", $params->{'foo'};

    %params = $q->Vars;  # as a plain hash
    print $params{'address'};
    @foo = split "\0", $params{'foo'};

    %params = $q->Vars(','); # specifying a different separator than "\0"
    @foo = split ',', $params{'foo'};

Many people want to fetch the entire parameter list as a hash in which the keys are the names of the CGI parameters, and the values are the parameters' values. The Vars() method does this.

Called in a scalar context, it returns the parameter list as a tied hash reference. Because this hash ref is tied changing a key/value changes the underlying CGI::Simple object.

Called in a list context, it returns the parameter list as an ordinary hash. Changing this hash will not change the underlying CGI::Simple object

When using Vars(), the thing you must watch out for are multi-valued CGI parameters. Because a hash cannot distinguish between scalar and list context, multi-valued parameters will be returned as a packed string, separated by the "\0" (null) character. You must split this packed string in order to get at the individual values. This is the convention introduced long ago by Steve Brenner in his cgi-lib.pl module for Perl version 4.

You can change the character used to do the multiple value packing by passing it to Vars() as an argument as shown.

url_param() Access the QUERY_STRING regardless of 'GET' or 'POST'

Technically what happens if you use this method is that the QUERY_STRING data is parsed into a new CGI::Simple object which is stored within the current object. url_param then just calls param() on this new object.

parse_query_string() Add QUERY_STRING data to 'POST' requests

    $q = CGI::Simple->new;
    $q->parse_query_string;  # add $ENV{'QUERY_STRING'} data to our $q object

If the REQUEST_METHOD was 'GET' then the QUERY_STRING will already be stored in our object so parse_query_string will be ignored.

This is a new method in CGI::Simple that is not available in CGI.pm

save() Saving the state of an object to file

    $q->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 new() method.

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 new().

    open my $fh, '<', "test.in" or die $!;
    $q1 = CGI::Simple->new($fh);  # get the first record
    $q2 = CGI::Simple->new($fh);  # get the next record

Note: If you wish to use this method from the function-oriented (non-OO) interface, the exported name for this method is save_parameters(). Also if you want to initialize from a file handle, the way to do this is with restore_parameters(). This will (re)initialize the default CGI::Simple object from the indicated file handle.

    restore_parameters($fh);

upload() The key file upload method

    $number_of_files = $q->upload;
    @list_of_files   = $q->upload;

Having established that you have uploaded files available you can get the browser supplied filename using param() like this:

    $filename1 = $q->param('upload_file1');

You can then get a filehandle to read from by calling upload() and supplying this filename as an argument. Warning: do not modify the value you get from param() in any way - you don't need to untaint it.

    $fh = $q->upload( $filename1 );

Now to save the file you would just do something like:

    $save_path = '/path/to/write/file.name';
    open my $out, '>', $save_path or die "Oops $!\n";
    binmode $out;
    print $out $buffer while read( $fh, $buffer, 4096 );
    close $out;

By utilizing a new feature of the upload method this process can be simplified to:

    $ok = $q->upload( $q->param('upload_file1'), '/path/to/write/file.name' );
    if ($ok) {
        print "Uploaded and wrote file OK!";
    } else {
        print $q->cgi_error();
    }

As you can see upload will accept an optional second argument and will write the file to this file path. It will return 1 for success and undef if it fails. If it fails you can get the error from cgi_error

You can also use just the fieldname as an argument to upload ie:

    $fh = $q->upload( 'upload_field_name' );

    or

    $ok = $q->upload( 'upload_field_name', '/path/to/write/file.name' );

BUT there is a catch. If you have multiple upload fields, all called 'upload_field_name' then you will only get the last uploaded file from these fields.

upload_info() Get the details about uploaded files

    $number_of_upload_files   = $q->upload_info();
    @filenames_of_all_uploads = $q->upload_info();

You can get the MIME type of an uploaded file like this:

    $mime = $q->upload_info( $filename1, 'mime' );

If you want to know how big a file is before you copy it you can get that information from uploadInfo which will return the file size in bytes.

    $file_size = $q->upload_info( $filename1, 'size' );

The size attribute is optional as this is the default value returned.

Note: The old CGI.pm uploadInfo() method has been deleted.

$POST_MAX and $DISABLE_UPLOADS

When file uploads are disabled the file name and file size details will still be available from param() and upload_info respectively but the upload filehandle returned by upload() will be undefined - not surprising as the underlying temp file will not exist either.

You can enable uploads using the '-upload' pragma. You do this by specifying this in you use statement:

    use CGI::Simple qw(-upload);

Alternatively you can enable uploads via the $DISABLE_UPLOADS global like this:

    use CGI::Simple;
    $CGI::Simple::DISABLE_UPLOADS = 0;
    $q = CGI::Simple->new;

If you wish to set $DISABLE_UPLOADS you must do this *after* the use statement and *before* the new constructor call as shown above.

The maximum acceptable data via post is capped at 102_400kB rather than infinity which is the CGI.pm default. This should be ample for most tasks but you can set this to whatever you want using the $POST_MAX global.

    use CGI::Simple;
    $CGI::Simple::DISABLE_UPLOADS = 0;      # enable uploads
    $CGI::Simple::POST_MAX = 1_048_576;     # allow 1MB uploads
    $q = CGI::Simple->new;

If you set to -1 infinite size uploads will be permitted, which is the CGI.pm default.

    $CGI::Simple::POST_MAX = -1;            # infinite size upload

Alternatively you can specify all the CGI.pm default values which allow file uploads of infinite size in one easy step by specifying the '-default' pragma in your use statement.

    use CGI::Simple qw( -default ..... );

binmode() and Win32

escapeHTML() Escaping HTML special characters

    $escaped = $q->escapeHTML( $string );

    $escaped = $q->escapeHTML( $string, 'new_lines_too' );

If the optional second argument is supplied then newlines will be escaped to.

unescapeHTML() Unescape HTML special characters

    $unescaped = $q->unescapeHTML( $HTML_escaped_string );

url_decode() Decode a URL encoded string

    $decoded = $q->url_decode( $encoded );

url_encode() URL encode a string

    $encoded = $q->url_encode( $string );

parse_keywordlist() Parse a supplied keyword list

    @keywords = $q->parse_keywordlist( $keyword_list );

This method returns a list of keywords, correctly URL escaped and split out of the supplied string

put() Send output to browser

print() Send output to browser

cookie() A simple access method to cookies

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

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

-name

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

-value

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:

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

-path

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

-domain

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

-expires

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

    "+1h"  one hour from now
    

-secure

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

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

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

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

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

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

    use CGI::Simple;
    $q = CGI::Simple->new;
    $riddle  = $q->cookie('riddle_name');
    %answers = $q->cookie('answers');

Cookies created with a single scalar value, such as the "riddle_name" cookie, will be returned in that form. Cookies with array and hash values can also be retrieved.

The cookie and CGI::Simple namespaces are separate. If you have a parameter named 'answers' and a cookie named 'answers', the values retrieved by param() and cookie() 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')] );

raw_cookie()

Called with no parameters, raw_cookie() 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 unescaped form of the cookie. You can use the regular cookie() method to get the names, or use the raw_fetch() method from the CGI::Simmple::Cookie module.

header() Create simple or complex HTTP headers

    print $q->header;

         -or-

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

         -or-

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

         -or-

    print $q->header( -type       => 'image/gif',
                      -nph        => 1,
                      -status     => '402 Payment required',
                      -expires    => '+3d',
                      -cookie     => $cookie,
                      -charset    => 'utf-7',
                      -attachment => 'foo.gif',
                      -Cost       => '$2.00'
                    );

header() 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 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 -type, -status, -cookie, -target, -expires, -nph, -charset and -attachment. 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.

For example, you can produce non-standard HTTP header fields by providing them as named arguments:

  print $q->header( -type            => 'text/html',
                    -nph             => 1,
                    -cost            => 'Three smackers',
                    -annoyance_level => 'high',
                    -complaints_to   => 'bit bucket'
                  );

This will produce the following non-standard HTTP header:

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

Note that underscores are translated automatically into hyphens. This feature allows you to keep up with the rapidly changing HTTP "standards".

The -type is a key element that tell the browser how to display your document. The default is 'text/html'. Common types are:

    text/html
    text/plain
    image/gif
    image/jpg
    image/png
    application/octet-stream

The -status code is the HTTP response code. The default is 200 OK. Common status codes are:

    200 OK
    204 No Response
    301 Moved Permanently
    302 Found
    303 See Other
    307 Temporary Redirect
    400 Bad Request
    401 Unauthorized
    403 Forbidden
    404 Not Found
    405 Not Allowed
    408 Request Timed Out
    500 Internal Server Error
    503 Service Unavailable
    504 Gateway Timed Out

The -expires parameter lets you indicate to a browser and proxy server how long to cache pages for. 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 -cookie 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 cookie() method to create and retrieve session cookies.

The -target is for frames use

The -nph 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 that expect all their scripts to be NPH.

The -charset parameter can be used to control the character set sent to the browser. If not provided, defaults to ISO-8859-1. As a side effect, this sets the charset() method as well.

The -attachment parameter can be used to turn the page into an attachment. Instead of displaying the page, some browsers will prompt the user to save it to disk. The value of the argument is the suggested name for the saved file. In order for this to work, you may have to set the -type to 'application/octet-stream'.

no_cache() Preventing browser caching of scripts

    $q->no_cache(1); # turn caching off by sending appropriate headers
    $q->no_cache(1); # do not send cache related headers.

    $q->no_cache(1);
    print header (-type=>'image/gif', -nph=>1);

    This will produce a header like the following:

    HTTP/1.0 200 OK
    Server: Apache - accept no substitutes
    Expires: Thu, 15 Nov 2001 03:37:50 GMT
    Date: Thu, 15 Nov 2001 03:37:50 GMT
    Pragma: no-cache
    Content-Type: image/gif

Both the Pragma: no-cache header field and an Expires header that corresponds to the current time (ie now) will be sent.

cache() Preventing browser caching of scripts

redirect() Generating a redirection header

    print $q->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 redirect() function redirects the browser to a different URL. If you use redirection like this, you should not print out a header as well.

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

The -nph 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 ones, which expect all their scripts to be NPH.

multipart_init() Initialize the multipart system

    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() Start a new part of the multipart document

    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() End a multipart part

    multipart_end()

End a part. You must remember to call multipart_end() once for each multipart_start(), except at the end of the last part of the multipart document when multipart_final() should be called instead of multipart_end().

multipart_final()

    multipart_final()

End all parts. You should call multipart_final() rather than multipart_end() at the end of the last part of the multipart document.

CGI::Push

Dump() Dumping the current object details

    print $q->Dump

The actual result of this is HTML escaped formatted text wrapped in <pre> tags so if you send it straight to the browser it produces something that looks like:

    $VAR1 = bless( {
         '.parameters' => [
                            'name',
                            'color'
                          ],
         '.globals' => {
                         'FATAL' => -1,
                         'DEBUG' => 0,
                         'NO_NULL' => 1,
                         'POST_MAX' => 102400,
                         'USE_CGI_PM_DEFAULTS' => 0,
                         'HEADERS_ONCE' => 0,
                         'NPH' => 0,
                         'DISABLE_UPLOADS' => 1,
                         'NO_UNDEF_PARAMS' => 0,
                         'USE_PARAM_SEMICOLONS' => 0
                       },
         '.fieldnames' => {
                            'color' => '1',
                            'name' => '1'
                          },
         '.mod_perl' => '',
         'color' => [
                      'red',
                      'green',
                      'blue'
                    ],
         'name' => [
                     'JaPh,'
                   ]
        }, 'CGI::Simple' );

You may recognize this as valid Perl syntax (which it is) and/or the output from Data::Dumper (also true). This is the actual guts of how the information is stored in the query object. All the internal params start with a . char

Alternatively you can dump your object and the current environment using:

    print $q->Dump(\%ENV);

PrintEnv() Dumping the environment

    print $q->PrintEnv;

This will produce something like (in the browser):

    $VAR1 = {
          'QUERY_STRING' => 'name=JaPh%2C&color=red&color=green&color=blue',
          'CONTENT_TYPE' => 'application/x-www-form-urlencoded',
          'REGRESSION_TEST' => 'simple.t.pl',
          'VIM' => 'C:\\WINDOWS\\Desktop\\vim',
          'HTTP_REFERER' => 'xxx.sex.com',
          'HTTP_USER_AGENT' => 'LWP',
          'HTTP_ACCEPT' => 'text/html;q=1, image/gif;q=0.42, */*;q=0.001',
          'REMOTE_HOST' => 'localhost',
          'HTTP_HOST' => 'the.restaurant.at.the.end.of.the.universe',
          'GATEWAY_INTERFACE' => 'bleeding edge',
          'REMOTE_IDENT' => 'None of your damn business',
          'SCRIPT_NAME' => '/cgi-bin/foo.cgi',
          'SERVER_NAME' => 'nowhere.com',
          'HTTP_COOKIE' => '',
          'CONTENT_LENGTH' => '42',
          'HTTPS_A' => 'A',
          'HTTP_FROM' => 'spammer@nowhere.com',
          'HTTPS_B' => 'B',
          'SERVER_PROTOCOL' => 'HTTP/1.0',
          'PATH_TRANSLATED' => '/usr/local/somewhere/else',
          'SERVER_SOFTWARE' => 'Apache - accept no substitutes',
          'PATH_INFO' => '/somewhere/else',
          'REMOTE_USER' => 'Just another Perl hacker,',
          'REMOTE_ADDR' => '127.0.0.1',
          'HTTPS' => 'ON',
          'DOCUMENT_ROOT' => '/vs/www/foo',
          'REQUEST_METHOD' => 'GET',
          'REDIRECT_QUERY_STRING' => '',
          'AUTH_TYPE' => 'PGP MD5 DES rot13',
          'COOKIE' => 'foo=a%20phrase; bar=yes%2C%20a%20phrase&;I%20say;',
          'SERVER_PORT' => '8080'
        };

cgi_error() Retrieving CGI::Simple error messages

    my $error = $q->cgi_error;
    if ($error) {
        print $q->header(-status=>$error);
        print "<H2>$error</H2>;
      exit;
    }

version() Get the CGI::Simple version info

    $version = $q->version();

The version() method returns the value of $VERSION

nph() Enable/disable NPH (Non Parsed Header) mode

    $q->nph(1);  # enable NPH mode
    $q->nph(0);  # disable NPH mode

The nph() method enables and disables NPH headers. See the NPH section.

all_parameters() Get the names/values of all parameters

    @all_parameters = $q->all_parameters();

The all_parameters() method is an alias for param()

charset() Get/set the current character set.

    $charset = $q->charset(); # get current charset
    $q->charset('utf-42');    # set the charset

The charset() method gets the current charset value if no argument is supplied or sets it if an argument is supplied.

crlf() Get the system specific line ending sequence

    $crlf = $q->crlf();

The crlf() method returns the system specific line ending sequence.

globals() Get/set the value of the remaining global variables

    $globals = $q->globals('FATAL');     # get the current value of $FATAL
    $globals = $q->globals('FATAL', 1 ); # set croak mode on cgi_error()

The globals() method gets/sets the values of the global variables after the script has been invoked. For globals like $POST_MAX and $DISABLE_UPLOADS this makes no difference as they must be set prior to calling the new constructor but there might be reason the change the value of others.

auth_type() Get the current authorization/verification method

    $auth_type = $q->auth_type();

The auth_type() method returns the value of $ENV{'AUTH_TYPE'} which should contain the authorization/verification method in use for this script, if any.

content_length() Get the content length submitted in a POST

    $content_length = $q->content_length();

The content_length() method returns the value of $ENV{'AUTH_TYPE'}

content_type() Get the content_type of data submitted in a POST

    $content_type = $q->content_type();

The content_type() method returns the content_type of data submitted in a POST, generally 'multipart/form-data' or 'application/x-www-form-urlencoded' as supplied in $ENV{'CONTENT_TYPE'}

document_root() Get the document root

    $document_root = $q->document_root();

The document_root() method returns the value of $ENV{'DOCUMENT_ROOT'}

gateway_interface() Get the gateway interface

    $gateway_interface = $q->gateway_interface();

The gateway_interface() method returns the value of $ENV{'GATEWAY_INTERFACE'}

path_translated() Get the value of path translated

    $path_translated = $q->path_translated();

The path_translated() method returns the value of $ENV{'PATH_TRANSLATED'}

referer() Spy on your users

    $referer = $q->referer();

The referer() method returns the value of $ENV{'REFERER'} This will return the URL of the page the browser was viewing prior to fetching your script. Not available for all browsers.

remote_addr() Get the remote address

    $remote_addr = $q->remote_addr();

The remote_addr() method returns the value of $ENV{'REMOTE_ADDR'} or 127.0.0.1 (localhost) if this is not defined.

remote_host() Get a value for remote host

    $remote_host = $q->remote_host();

The remote_host() method returns the value of $ENV{'REMOTE_HOST'} if it is defined. If this is not defined it returns $ENV{'REMOTE_ADDR'} If this is not defined it returns 'localhost'

remote_ident() Get the remote identity

    $remote_ident = $q->remote_ident();

The remote_ident() method returns the value of $ENV{'REMOTE_IDENT'}

remote_user() Get the remote user

    $remote_user = $q->remote_user();

The remote_user() method returns the authorization/verification name used for user verification, if this script is protected. The value comes from $ENV{'REMOTE_USER'}

request_method() Get the request method

    $request_method = $q->request_method();

The request_method() method returns the method used to access your script, usually one of 'POST', 'GET' or 'HEAD' as supplied by $ENV{'REQUEST_METHOD'}

script_name() Get the script name

    $script_name = $q->script_name();

The script_name() method returns the value of $ENV{'SCRIPT_NAME'} if it is defined. Otherwise it returns Perl's script name from $0. Failing this it returns a null string ''

server_name() Get the server name

    $server_name = $q->server_name();

The server_name() method returns the value of $ENV{'SERVER_NAME'} if defined or 'localhost' otherwise

server_port() Get the port the server is listening on

    $server_port = $q->server_port();

The server_port() method returns the value $ENV{'SERVER_PORT'} if defined or 80 if not.

server_protocol() Get the current server protocol

    $server_protocol = $q->server_protocol();

The server_protocol() method returns the value of $ENV{'SERVER_PROTOCOL'} if defined or 'HTTP/1.0' otherwise

server_software() Get the server software

    $server_software = $q->server_software();

The server_software() method returns the value $ENV{'SERVER_SOFTWARE'} or 'cmdline' If the server software is IIS it formats your hard drive, installs Linux, FTPs to www.apache.org, installs Apache, and then restores your system from tape. Well maybe not, but it's a nice thought.

user_name() Get a value for the user name.

    $user_name = $q->user_name();

Attempt to obtain the remote user's name, using a variety of different techniques. This only works with older browsers such as Mosaic. Newer browsers do not report the user name for privacy reasons!

Technically the user_name() method returns the value of $ENV{'HTTP_FROM'} or failing that $ENV{'REMOTE_IDENT'} or as a last choice $ENV{'REMOTE_USER'}

user_agent() Get the users browser type

    $ua = $q->user_agent();          # return the user agent
    $ok = $q->user_agent('mozilla'); # return true if user agent 'mozilla'

The user_agent() method returns the value of $ENV{'HTTP_USER_AGENT'} when called without an argument or true or false if the $ENV{'HTTP_USER_AGENT'} matches the passed argument. The matching is case insensitive and partial.

virtual_host() Get the virtual host

    $virtual_host = $q->virtual_host();

The virtual_host() method returns the value of $ENV{'HTTP_HOST'} if defined or $ENV{'SERVER_NAME'} as a default. Port numbers are removed.

path_info() Get any extra path info set to the script

    $path_info = $q->path_info();

The path_info() method returns additional path information from the script URL. E.G. fetching /cgi-bin/your_script/additional/stuff will result in $q->path_info() 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.

Accept() Get the browser MIME types

    $Accept = $q->Accept();

The Accept() method returns 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 $q->Accept('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.

accept() Alias for Accept()

    $accept = $q->accept();

The accept() Method is an alias for Accept()

http() Get a range of HTTP related information

    $http = $q->http();

Called with no arguments the http() method returns the list of HTTP or HTTPS environment variables, including such things as HTTP_USER_AGENT, HTTP_ACCEPT_LANGUAGE, and HTTP_ACCEPT_CHARSET, corresponding to the like-named HTTP header fields in the request. Called with the name of an HTTP header field, returns its value. Capitalization and the use of hyphens versus underscores are not significant.

For example, all three of these examples are equivalent:

   $requested_language = $q->http('Accept-language');
   $requested_language = $q->http('Accept_language');
   $requested_language = $q->http('HTTP_ACCEPT_LANGUAGE');

https() Get a range of HTTPS related information

    $https = $q->https();

The https() method is similar to the http() method except that when called without an argument it returns the value of $ENV{'HTTPS'} which will be true if a HTTPS connection is in use and false otherwise.

protocol() Get the current protocol

    $protocol = $q->protocol();

The protocol() method returns 'https' if a HTTPS connection is in use or the server_protocol() minus version numbers ('http') otherwise.

url() Return the script's URL in several formats

    $full_url      = $q->url();
    $full_url      = $q->url(-full=>1);
    $relative_url  = $q->url(-relative=>1);
    $absolute_url  = $q->url(-absolute=>1);
    $url_with_path = $q->url(-path_info=>1);
    $url_with_path_and_query = $q->url(-path_info=>1,-query=>1);
    $netloc        = $q->url(-base => 1);

url() 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:

-absolute

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

    /path/to/script.cgi
    

-relative

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

    script.cgi
    

-full

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

-path (-path_info)

Append the additional path information to the URL. This can be combined with -full, -absolute or -relative. -path_info is provided as a synonym.

-query (-query_string)

Append the query string to the URL. This can be combined with -full, -absolute or -relative. -query_string is provided as a synonym.

-base

Generate just the protocol and net location, as in http://www.foo.com:8000

self_url() Get the scripts complete URL

    $self_url = $q->self_url();

The self_url() method returns the value of:

   $self->url( '-path_info'=>1, '-query'=>1, '-full'=>1 );

state() Alias for self_url()

    $state = $q->state();

The state() method is an alias for self_url()

Globals Variables

    $VERSION = "0.01";
    # set this to 1 to use CGI.pm default global settings
    $USE_CGI_PM_DEFAULTS = 0 unless defined $USE_CGI_PM_DEFAULTS;
    # see if user wants old  CGI.pm defaults
    do{ _use_cgi_pm_global_settings(); return } if $USE_CGI_PM_DEFAULTS;
    # no file uploads by default, set to 0 to enable uploads
    $DISABLE_UPLOADS = 1 unless defined $DISABLE_UPLOADS;
    # use a post max of 100K, set to -1 for no limits
    $POST_MAX = 102_400 unless defined $POST_MAX;
    # do not include undefined params parsed from query string
    $NO_UNDEF_PARAMS = 0 unless defined $NO_UNDEF_PARAMS;
    # separate the name=value pairs with ; rather than &
    $USE_PARAM_SEMICOLONS = 0 unless defined $USE_PARAM_SEMICOLONS;
    # only print headers once
    $HEADERS_ONCE = 0 unless defined $HEADERS_ONCE;
    # Set this to 1 to enable NPH scripts
    $NPH = 0 unless defined $NPH;
    # 0 => no debug, 1 => from @ARGV,  2 => from STDIN
    $DEBUG = 0 unless defined $DEBUG;
    # filter out null bytes in param - value pairs
    $NO_NULL  = 1 unless defined $NO_NULL;
    # set behavior when cgi_err() called -1 => silent, 0 => carp, 1 => croak
    $FATAL = -1 unless defined $FATAL;

Four of the default values of the old CGI.pm variables have been changed. Unlike CGI.pm which by default allows unlimited POST data and file uploads by default CGI::Simple limits POST data size to 100kB and denies file uploads by default. $USE_PARAM_SEMICOLONS is set to 0 by default so we use (old style) & rather than ; as the pair separator for query strings. Debugging is disabled by default.

There are three new global variables. If $NO_NULL is true (the default) then CGI::Simple will strip null bytes out of names, values and keywords. Null bytes can do interesting things to C based code like Perl. Uploaded files are not touched. $FATAL controls the behavior when cgi_error() is called. The default value of -1 makes errors silent. $USE_CGI_PM_DEFAULTS reverts the defaults to the CGI.pm standard values ie unlimited file uploads via POST for DNS attacks. You can also get the defaults back by using the '-default' pragma in the use:

    use CGI::Simple qw(-default);
    use CGI::Simple::Standard qw(-default);

The values of the global variables are stored in the CGI::Simple object and can be referenced and changed using the globals() method like this:

    my $value = $q->globals( 'VARNAME' );      # get
    $q->globals( 'VARNAME', 'some value' );    # set

As with many CGI.pm methods if you pass the optional value that will be set.

The $CGI::Simple::VARNAME = 'N' syntax is only useful prior to calling the new() constructor. After that all reference is to the values stored in the CGI::Simple object so you must change these using the globals() method.

$DISABLE_UPLOADS and $POST_MAX *must* be set prior to calling the constructor if you want the changes to have any effect as they control behavior during initialization. This is the same a CGI.pm although some people seem to miss this rather important point and set these after calling the constructor which does nothing.

The following globals are no longer relevant and have all been deleted:

    $AUTOLOADED_ROUTINES
    $AUTOLOAD_DEBUG
    $BEEN_THERE
    $CRLF
    $DEFAULT_DTD
    $EBCDIC
    $FH
    $FILLUNIT
    $IIS
    $IN
    $INITIAL_FILLUNIT
    $JSCRIPT
    $MAC
    $MAXTRIES
    $MOD_PERL
    $NOSTICKY
    $OS
    $PERLEX
    $PRIVATE_TEMPFILES
    $Q
    $QUERY_CHARSET
    $QUERY_PARAM
    $SCRATCH
    $SL
    $SPIN_LOOP_MAX
    $TIMEOUT
    $TMPDIRECTORY
    $XHTML
    %EXPORT
    %EXPORT_OK
    %EXPORT_TAGS
    %OVERLOAD
    %QUERY_FIELDNAMES
    %SUBS
    @QUERY_PARAM
    @TEMP

Notes: CGI::Simple uses IO::File->new_tmpfile to get tempfile filehandles. These are private by default so $PRIVATE_TEMPFILES is no longer required nor is $TMPDIRECTORY. The value that were stored in $OS, $CRLF, $QUERY_CHARSET and $EBCDIC are now stored in the CGI::Simple::Util object where they find most of their use. The $MOD_PERL and $PERLEX values are now stored in our CGI::Simple object. $IIS was only used once in path_info(). $SL the system specific / \ : path delimiter is not required as we let IO::File handle our tempfile requirements. The rest of the globals are HTML related, export related, hand rolled autoload related or serve obscure purposes in CGI.pm

Changes to pragmas

    -any
    -compile
    -nosticky
    -no_xhtml
    -private_tempfiles

Filehandles

Hash interface

    %hash = $q->Vars();     # pack values with "\0";
    %hash = $q->Vars(",");  # comma separate values

You may optionally pass Vars() a string that will be used to separate multiple values when they are packed into the single hash value. If no value is supplied the default "\0" (null byte) will be used. Null bytes are dangerous things for C based code (ie Perl).

cgi-lib.pl

Guts (hands off, except of course for new)

    _initialize_globals
    _use_cgi_pm_global_settings
    _store_globals
    import
    _reset_globals
    new
    _initialize
    _read_parse
    _parse_params
    _add_param
    _parse_keywordlist
    _parse_multipart
    _save_tmpfile
    _read_data

Core Methods

    param
    add_param
    param_fetch
    url_param
    keywords
    Vars
    append
    delete
    Delete
    delete_all
    Delete_all
    upload
    upload_info
    query_string
    parse_query_string
    parse_keywordlist

Save and Restore from File Methods

    _init_from_file
    save
    save_parameters

Miscellaneous Methods

    url_decode
    url_encode
    escapeHTML
    unescapeHTML
    put
    print

Cookie Methods

    cookie
    raw_cookie

Header Methods

    header
    cache
    no_cache
    redirect

Server Push Methods

    multipart_init
    multipart_start
    multipart_end
    multipart_final

Debugging Methods

    read_from_cmdline
    Dump
    as_string
    cgi_error

cgi-lib.pl Compatibility Routines - all 2.18 functions available

    _shift_if_ref
    ReadParse
    SplitParam
    MethGet
    MethPost
    MyBaseUrl
    MyURL
    MyFullUrl
    PrintHeader
    HtmlTop
    HtmlBot
    PrintVariables
    PrintEnv
    CgiDie
    CgiError

Accessor Methods

    version
    nph
    all_parameters
    charset
    crlf                # new, returns OS specific CRLF sequence
    globals             # get/set global variables
    auth_type
    content_length
    content_type
    document_root
    gateway_interface
    path_translated
    referer
    remote_addr
    remote_host
    remote_ident
    remote_user
    request_method
    script_name
    server_name
    server_port
    server_protocol
    server_software
    user_name
    user_agent
    virtual_host
    path_info
    Accept
    accept
    http
    https
    protocol
    url
    self_url
    state

Internal Routines

    _initialize_globals()
    _use_cgi_pm_global_settings()
    _store_globals()
    _initialize()
    _init_from_file()
    _read_parse()
    _parse_params()
    _add_param()
    _parse_keywordlist()
    _parse_multipart()
    _save_tmpfile()
    _read_data()

New Public Methods

    add_param()             # adds a param/value(s) pair +/- overwrite
    upload_info()           # uploaded files MIME type and size
    url_decode()            # decode s url encoded string
    url_encode()            # url encode a string
    parse_query_string()    # add QUERY_STRING data to $q object if 'POST'
    no_cache()              # add both the Pragma: no-cache
                            # and Expires/Date => 'now' to header

cgi-lib.pl methods added for completeness

    _shift_if_ref()         # internal hack reminiscent of self_or_default :-)
    MyBaseUrl()
    MyURL()
    MyFullUrl()
    PrintVariables()
    PrintEnv()
    CgiDie()
    CgiError()

New Accessors

    crlf()                  # returns CRLF sequence
    globals()               # global vars now stored in $q object - get/set
    content_length()        # returns $ENV{'CONTENT_LENGTH'}
    document_root()         # returns $ENV{'DOCUMENT_ROOT'}
    gateway_interface()     # returns $ENV{'GATEWAY_INTERFACE'}

Guts - rearranged, recoded, renamed and hacked out of existence

    initialize_globals()
    compile()
    expand_tags()
    self_or_default()
    self_or_CGI()
    init()
    to_filehandle()
    save_request()
    parse_params()
    add_parameter()
    binmode()
    _make_tag_func()
    AUTOLOAD()
    _compile()
    _setup_symbols()
    new_MultipartBuffer()
    read_from_client()
    import_names()     # I dislike this and left it out, so shoot me.

HTML Related

    autoEscape()
    URL_ENCODED()
    MULTIPART()
    SERVER_PUSH()
    start_html()
    _style()
    _script()
    end_html()
    isindex()
    startform()
    start_form()
    end_multipart_form()
    start_multipart_form()
    endform()
    end_form()
    _textfield()
    textfield()
    filefield()
    password_field()
    textarea()
    button()
    submit()
    reset()
    defaults()
    comment()
    checkbox()
    checkbox_group()
    _tableize()
    radio_group()
    popup_menu()
    scrolling_list()
    hidden()
    image_button()
    nosticky()
    default_dtd()

Upload Related

    private_tempfiles() # automatic in CGI::Simple
    tmpFileName()       # all upload files are anonymous
    uploadInfo()        # relied on FH access, replaced with upload_info()

Really Private Subs (marked as so)

    previous_or_default()
    register_parameter()
    get_fields()
    _set_values_and_labels()
    _compile_all()
    asString()
    compare()

Internal Multipart Parsing Routines

    read_multipart()
    readHeader()
    readBody()
    read()
    fillBuffer()
    eof()