Provided by: libdata-showtable-perl_4.6-1_all bug

NAME

       ShowTable - routines to display tabular data in several formats.

USAGE

       "use Data::ShowTable;"

       ShowTable { parameter => value, ... };

       ShowTable \@titles, \@types, \@widths, \&row_sub [, \&fmt_sub ];

       ShowDatabases \@dbnames;

       ShowDatabases { parameter => value, ... };

       ShowTables \@tblnames;

       ShowTables { parameter => value, ... };

       ShowColumns \@columns, \@col_types, \@col_lengths, \@col_attrs;

       ShowColumns { parameter => value, ... };

       ShowBoxTable \@titles, \@types, \@widths, \&row_sub [, \&fmt_sub ];

       ShowBoxTable { parameter => value, ... };

       ShowSimpleTable \@titles, \@types, \@widths, \&row_sub [, \&fmt_sub];

       ShowSimpleTable { parameter => value, ... };

       ShowHTMLTable \@titles, \@types, \@widths, \&row_sub [, \&fmt_sub];

       ShowHTMLTable { parameter => value, ... };

       ShowListTable \@titles, \@types, \@widths, \&row_sub [, \&fmt_sub];

       ShowListTable { parameter => value, ... };

       "package Data::ShowTable";

       $Show_Mode = 'mode';

       $Max_Table_Width = number;

       $Max_List_Width = number;

       $No_Escape = flag;

       %URL_Keys = { "$colname" => "$col_URL", ... };

       @Title_Formats = ( fmt1_html, <fmt2_html>, ... );

       @Data_Formats = ( fmt1_html, <fmt2_html>, ... );

       ShowRow $rewindflag, \$index, $col_array_1 [, $col_array_2, ...;]

       $fmt = ShowTableValue $value, $type, $max_width, $width, $precision, $showmode;

       [$plaintext = ] PlainText [$htmltext];

DESCRIPTION

       The ShowTable module provides subroutines to display tabular data, typially from a database, in nicely
       formatted columns, in several formats.  Its arguments can either be given in a fixed order, or, as a
       single, anonymous hash-array.

       The output format for any one invocation can be one of four possible styles:

       Box       A tabular format, with the column titles and the entire table surrounded by a "box" of ""+"",
                 ""-"", and ""|"" characters.  See "ShowBoxTable" for details.

       Table     A simple tabular format, with columns automatically aligned, with column titles.  See
                 "ShowSimpleTable".

       List      A list style, where columns of data are listed as a name:value pair, one pair per line, with
                 rows being one or more column values, separated by an empty line.  See "ShowListTable".

       HTML      The data is output as an HTML TABLE, suitable for display through a Web-client.  See
                 "ShowHTMLTable".  Input can either be plain ASCII text, or text with embedded HTML elements,
                 depending upon an argument or global parameter.

       The subroutines which perform these displays are listed below.

EXPORTED NAMES

       This module exports the following subroutines:

        ShowDatabases    - show list of databases
        ShowTables       - show list of tables
        ShowColumns      - show table of column info
        ShowTable        - show a table of data
        ShowRow          - show a row from one or more columns
        ShowTableValue   - show a single column's value
        ShowBoxTable     - show a table of data in a box
        ShowListTable    - show a table of data in a list
        ShowSimpleTable  - show a table of data in a simple table
        ShowHTMLTable    - show a table of data using HTML
        PlainText        - convert HTML text into plain text

       All of these subroutines, and others, are described in detail in the following sections.

MODULES

ShowTable

       Format and display the contents of one or more rows of data.

         ShowTable { parameter => value, ... };

         ShowTable \@titles, \@types, \@widths, \&row_sub [, \&fmt_sub [, $max_width ] [, $show_mode ] ];

       The ShowTable subroutine displays tabular data aligned in columns, with headers.  ShowTable supports four
       modes of display: Box, Table, List, and HTML.  Each mode is described separately below.

       The arguments to ShowTable may be given in one of two ways: as a hashed-array, or by a combination of
       fixed order arguments, and some package-global variable settings.  The hash-array parameters correspond
       to the fixed arguments and the global-parameter settings.

       In the list below, both the hash-array parameter name and the fixed-order argument name is given as the
       value.  In the case where there is no fixed-order argument for a given parameter-value pair, then the
       corresponding global variable name is given.

       "titles" => \@titles
                 A reference to an array of column names, or titles.  If a particular column name is null, then
                 the string "Field_num" is used by default.  To have a column have no title, use the empty
                 string.

       "types" => \@types
                 A reference to an array of types, one for each column.  These types are passed to the fmt_sub
                 for appropriate formatting.  Also, if a column type matches the regexp ""/text|char|string/i"",
                 then the column alignment will be left-justified, otherwise it will be right-justified.

       "widths" => \@widths
                 A reference to an array of column widths, which may be given as an integer, or as a string of
                 the form: "width.precision".

       "row_sub" => \&row_sub
                 A reference to a subroutine which successively returns rows of values in an array.  It is
                 called for two purposes, each described separately:

                 * To fetch successive rows of data:

                     @row = &$row_sub(0);

                 When given a null, zero, or empty argument, the next row is returned.

                 * To initialize or rewind the data traversal.

                     $rewindable = &$row_sub(1);

                 When invoked with a non-null argument, the subroutine should rewind its row pointer to start at
                 the first row of data.  If the data which row_sub is traversing is not rewindable, it must
                 return zero or null.  If the data is rewindable, a non-null, non-zero value should be returned.

                 The row_sub must expect to be invoked once with a non-null argument, in order to discover
                 whether or not the data is rewindable.  If the data cannot be rewound, row_sub will thereafter
                 only be called with a zero argument.

                 Specifically, row_sub subroutine is used in this manner:

                     $rewindable = &$row_sub(1);
                     if ($rewindable) {
                         while ((@row = &$row_sub(0)), $#row >= 0) {
                             # examine lengths for optimal formatting
                         }
                         &$row_sub(1);   # rewind
                     }
                     while ((@row = &$row_sub(0)), $#row >= 0) {
                         # format the data
                     }

                 The consequence of data that is not rewindable, a reasonably nice table will still be
                 formatted, but it may contain fairly large amounts of whitespace for wide columns.

       "fmtsub" => \&fmt_sub
                 A reference to a subroutine which formats a value, according to its type, width, precision, and
                 the current column width.  It is invoked either with a fixed list of arguments, or with a hash-
                 array of parameter and value pairs.

                   $string = &fmt_sub { I<parameter> => I<value>, ... };

                   $string = &fmt_sub($value, $type, $max_width, $width, $precision)

                 If \&fmt_sub is omitted, then a default subroutine, ShowTableValue, will be used, which will
                 use Perl's standard string formatting rules.

                 The arguments to \&fmt_sub, either as values passed in a fixed order, or as part of the
                 parameter value pair, are described in the section on "ShowTableValue below.

       "max_width" => number,
                 The maximum table width, including the table formatting characters.  If not given, defaults to
                 the global variable $Max_Table_Width;

       "show_mode" => 'mode',
                 The display mode of the output.  One of five strings: 'Box', 'Table', 'Simple', 'List', and
                 'HTML'.

ShowDatabases

       Show a list of database names.

         ShowDatabases \@dbnames;

         ShowDatabases { 'data' => \@dbnames, parameter => value, ...};

       ShowDatabases is intended to be used to display a list of database names, under the column heading of
       "Databases".  It is a special case usage of ShowTable (and can thus be passed any parameter suitable for
       ShowTable.

       The argument, \@dbnames, is a reference to an array of strings, used as the values of the single column
       display.

ShowTables

       Show an array of table names.

         ShowTables \@tblnames;

         ShowTables { 'data' => \@tblnames, parameter => value, ...};

       ShowTables is used to display a list of table names, under the column heading of "Tables".  It is a
       special case usage of ShowTable, and can be passed any "ShowTable" argument parameter.

ShowColumns

       Display a table of column names, types, and attributes.

         ShowColumns { parameter => values, ... };

         ShowColumns \@columns, \@col_types, \@col_lengths, \@col_attrs;

       The ShowColumns subroutine displays a table of column names, types, lengths, and other attributes in a
       nicely formatted table.  It is a special case usage of ShowTable, and can be passed any argument suitable
       for "ShowTable";

       The arguments are:

       "columns" = \@columns
                 An array of column names.  This provides the value for the first column of the output.

       "col_types" = \@col_types
                 An array of column types names.  This provides the value for the second column.

       "col_lengths" = \@col_lengths
                 An array of maximum lengths for corresponding columns.  This provides the value for the third
                 column of the output.

       "col_attrs" = \@col_attrs
                 An array of column attributes array references (ie: an array of arrays).  The attributes array
                 for the first column are at "$col_attrs-\>[0]".  The first attribute of the second column is
                 "$col_attrs-\>[1][0]".

       The columns, types, lengths, and attributes are displayed in a table with the column headings: "Column",
       "Type", "Length", and "Attributes".  This is a special case usage of ShowTable, and can be passed
       additional arguments suitable for "ShowTable".

ShowBoxTable

       Show tabular data in a box.

         ShowBoxTable { parameter = value, ... };

         ShowBoxTable \@titles, \@types, \@widths, \&row_sub       [, [ \&fmt_sub ] [, $max_width ] ];

       The ShowBoxTable displays tabular data in titled columns using a "box" of ASCII graphics, looking
       something like this:

               +------------+----------+-----+----------+
               | Column1    | Column2  | ... | ColumnN  |
               +------------+----------+-----+----------+
               | Value11    | Value12  | ... | Value 1M |
               | Value21    | Value22  | ... | Value 2M |
               | Value31    | Value32  | ... | Value 3M |
               |  ...       |  ...     | ... |  ...     |
               | ValueN1    | ValueN2  | ... | Value NM |
               +------------+----------+-----+----------+

       The arguments are the same as with "ShowTable".  If the @titles array is empty, the header row is
       omitted.

ShowSimpleTable

       Display a table of data using a simple table format.

         ShowSimpleTable \@titles, \@types, \@widths, \&row_sub [, \&fmt_sub];

         ShowSimpleTable { parameter => values, ... };

       The ShowSimpleTable subroutine formats data into a simple table of aligned columns, in the following
       example:

          Column1  Column2  Column3
          -------  -------  -------
          Value1   Value2   Value3
          Value12  Value22  Value32

       Columns are auto-sized by the data's widths, plus two spaces between columns.  Values which are too long
       for the maximum colulmn width are wrapped within the column.

ShowHTMLTable

       Display a table of data nicely using HTML tables.

         ShowHTMLTable { parameter => value, ... };

         ShowHTMLTable \@titles, \@types, \@widths, \&row_sub [, \&fmt_sub [, $max_width [, \%URL_Keys [,
       $no_escape [, \@title_formats [, \@data_formats [, $table_attrs ] ] ] ] ] ] ];

       The ShowHTMLTable displays one or more rows of columns of data using the HTML "\<TABLE\"> feature.  In
       addition to the usual parameter arguments of "ShowTable", the following parameter arguments are defined:

       "url_keys" => \%URL_Keys,
                 This is a hash array of column names (titles) and corresponding base URLs.  The values of any
                 column names or indexes occuring as keys in the hash array will be generated as hypertext
                 anchors using the associated printf-like string as the base URL. Either the column name or the
                 column index (beginning with 1) may be used as the hash key.

                 In the string value, these macros can be substituted:

                 "%K" is replaced with the column name.

                 "%V" is replaced with the column value;

                 "%I" is replaced with the column index.

                 For example, if we define the array:

                     $base_url = "http://www.$domain/cgi/lookup?col=%K?val=%V";
                     %url_cols = ('Author' => $base_url,
                                  'Name'   => $base_url);

                 Then, the values in the "Author" column will be generated with the following HTML text:

                     <A HREF="http://www.$domain/cgi/lookup?col=Author?val=somevalue>somevalue</A>

                 and the values in the "Name" column will be generated with the URL:

                     <A HREF="http://www.$domain/cgi/lookup?col=Name?val=othervalue>othervalue</A>

                 If this variable is not given, it will default to the global variable "\%URL_Keys".

       "no_escape" => boolean,
                 Unless $no_escape is set, HTML-escaping is performed on the data values in order to properly
                 display the special HTML formatting characters : '\<', '\>', and '&'.  If you wish to display
                 data with embedded HTML text, you must set $no_escape.

                 Enabling embedded HTML, turns on certain heuristics which enable the user to more completely
                 define appearance of the table.  For instance, any "\<TR\"> tokens found embedded *anywhere*
                 within a row of data will be placed at the front of the row, within the generated "\<TR\">.

                 Similarly, a row of data containing the "\<THEAD\"> or "\<TFOOT\"> tokens, and their closing
                 counterparts, will begin and end, respectively a table header or footer data.

       "title_formats" => \@title_formats,
       "tformats" => \@title_formats,
                 An array of HTML formatting elements for the column titles, one for each column.  Each array
                 element is a list of one or more HTML elements, given as "\<ELEMENT\"> or plainly, "ELEMENT",
                 and separated by a comma ',', semi-colon ';', or vertical bar '|'.  Each given HTML element is
                 prepended to the corresponding column title, in the order given.  The corresponding HTML
                 closing elements are appended in the opposite order.

                 For example, if \@title_formats contains the two elements:

                     [ 'FONT SIZE=+2,BOLD', 'FONT COLOR=red,EM' ]

                 then the text output for the title of the first column would be:

                     <FONT SIZE=+2><BOLD>I<column_1_title></BOLD></FONT>

                 If "title_formats" is omitted, the global variable @Title_Formats is used by default.

       "data_formats" => \@data_formats,
       "dformats" => \@data_formats,
                 Similar to "title_formats", this array provides HTML formatting for the columns of each row of
                 data.  If "data_formats" is omitted or null, then the global variable \@Data_Formats is used by
                 default.

       "table_attrs" => $table_attrs,
                 This variable defines a string of attributes to be inserted within the "\<TABLE\"> token.  For
                 example, if the user wishes to have no table border:

                     ShowHTMLTable {
                         ...
                         table_attrs => 'BORDER=0',
                         ...
                     };

ShowListTable

       Display a table of data using a list format.

         ShowListTable { parameter => value, ... };

         ShowListTable \@titles, \@types, \@widths, \&row_sub [, \&fmt_sub [, $max_width [, $wrap_margin ] ] ];

       The arguments for ShowListTable are the same as for "ShowTable", except for those described next.

       "max_width" = number,
       "wrap_margin" = number,
                 Lines are truncated, and wrapped when their length exceeds $max_width.  Wrapping is done on a
                 word-basis, unless the resulting right margin exceeds $wrap_margin, in which case the line is
                 simply truncated at the $max_width limit.

                 The $max_width variable defaults to $Max_List_Width.  The $wrap_margin defaults to
                 $List_Wrap_Margin.

       In List mode, columns (called "fields" in List mode) are displayed wth a field name and value pair per
       line, with records being one or more fields .  In other words, the output of a table would look something
       like this:

           Field1_1: Value1_1
           Field1_2: Value1_2
           Field1_3: Value1_3
           ...
           Field1-N: Value1_M
           <empty line>
           Field2_1: Value2_1
           Field2_2: Value2_2
           Field2_3: Value2_3
           ...
           Field2_N: Value2_N
           ...
           FieldM_1: ValueM_1
           FieldM_2: ValueM_2
           ...
           FieldM_N: ValueM_N
           <empty line>
           <empty line>

       Characteristics of List mode:

       •         two empty lines indicate the end of data.

       •         An empty field (column) may be omitted, or may have a label, but no data.

       •         A long line can be continue by a null field (column):

                     Field2: blah blah blah
                           : blah blah blah

       •         On a continuation, the null field is an arbitrary number of leading white space, a colon ':', a
                 single blank or tab, followed by the continued text.

       •         Embedded newlines are indicated by the escape mechanism "\n".  Similarly, embedded tabs are
                 indicated with "\t", returns with "\r".

       •         If the @titles array is empty, the field names ""Field_"NN" are used instead.

ShowRow

       Fetch rows successively from one or more columns of data.

         ShowRow $rewindflag, \$index, $col_array_1 [, $col_array_2, ...;]

       The ShowRow subroutine returns a row of data from one or more columns of data.  It is designed to be used
       as a callback routine, within the ShowTable routine.   It can be used to select elements from one or more
       array reference arguments.

       If passed two or more array references as arguments, elements of the arrays selected by $index are
       returned as the "row" of data.

       If a single array argument is passed, and each element of the array is itself an array, the subarray is
       returned as the "row" of data.

       If the $rewindflag flag is set, then the $index pointer is reset to zero, and "true" is returned (a
       scalar 1).  This indicates that the data is rewindable to the ShowTable routines.

       When the $rewindflag is not set, then the current row of data, as determined by $index is returned, and
       $index will have been incremented.

       An actual invocation (from ShowColumns) is:

         ShowTable \@titles, \@types, \@lengths,
             sub { &ShowRow( $_[0], \$current_row, $col_names, $col_types,
                             $col_lengths, \@col_attrs); };

       In the example above, after each invocation, the $current_row argument will have been incremented.

ShowTableValue

       Prepare and return a formatted representation of a value.  A value argument, using its corresponding
       type, effective width, and precision is formatted into a field of a given maximum width.

         $fmt = ShowTableValue $value, $type, $max_width, $width, $precision, $showmode;

       "width" => $width
       $width    The width of the current value.  If omittied, $max_width is assumed.

       "precision" => $precision
       $precision
                 The number of decimal digits; zero is assumed if omittied.

       "value" => $value
       $value    The value to be formatted.

       $type     The type name of the value; eg: "char", "varchar", "int", etc.

       "maxwidth" => $max_width
       $max_width
                 The maximum width of any value in the current value's column.  If $width is zero or null,
                 $max_width is used by default.  $max_width is also used as a minimum width, in case $width is a
                 smaller value.

       $width    The default width of the value, obtained from the width specification of the column in which
                 this value occurs.

       $precision
                 The precision specification, if any, from the column width specification.

       $showmode The mode of the output: one of "table", "list", "box", or "html".  Currently, only the "html"
                 mode is significant: it is used to avoid using HTML tokens as part of the formatted text and
                 length calculations.

PlainText

         $plaintext = &PlainText($htmltext);

         &PlainText

       This function removes any HTML formatting sequences from the input argument, or from $_ if no argument is
       given.  The resulting plain text is returned as the result.

VARIABLES

       The following variables may be set by the user to affect the display (with the defaults enclosed in
       square brackets [..]):

       $Show_Mode [Box]
                 This is the default display mode when using ShowTable.  The environment variable,
                 $ENV{'SHOW_MODE'}, is used when this variable is null or the empty string.  The possible values
                 for this variable are: "Box", "List", "Table", and "HTML".  Case is insignificant.

       $List_Wrap_Margin [2]
                 This variable's value determines how large a margin to keep before wrarpping a long value's
                 display in a column.  This value is only used in "List" mode.

       $Max_List_Width [80]
                 This variable, used in "List" mode, is used to determine how long an output line may be before
                 wrapping it.  The environment variable, $ENV{'COLUMNS'}, is used to define this value when it
                 is null.

       $Max_Table_Width ['']
                 This variable, when set, causes all tables to have their columns scaled such that their total
                 combined width does not exceed this value.  When this variable is not set, which is the default
                 case, there is no maximum table width, and no scaling will be done.

       $No_Escape ['']
                 If set, allows embedded HTML text to be included in the data displayed in an HTML-formatted
                 table.  By default, the HTML formatting characters ("<", ">", and "&") occuring in values are
                 escaped.

       %URL_Keys In HTML mode, this variable is used to recognize which columns are to be displayed with a
                 corresponding hypertext anchor.  See "ShowHTMLTable" for more details.

       @HTML_Elements
                 An array of HTML elements (as of HTML 3.0) used to recognize and strip for width calculations.

       $HTML_Elements
                 A regular expression string formed from the elements of @HTML_Elements.

INTERNAL SUBROUTINES

get_params

         my $args = &get_params \@argv, \%params, \@arglist;

       Given the @argv originally passed to the calling sub, and the hash of named parameters as %params, and
       the array of parameter names in the order expected for a pass-by-value invocation, set the values of each
       of the variables named in @vars.

       If the only element of the @argv is a hash array, then set the variables to the values of their
       corresponding parameters used as keys to the hash array.  If the parameter is not a key of the %params
       hash, and is not a key in the global hash %ShowTableParams, then an error is noted.

       When @argv has multiple elements, or is not a hash array, set each variable, in the order given within
       @arglist, to the values from the @argv, setting the variables named by each value in %params.

       Variables may given either by name or by reference.

       The result is a HASH array reference, either corresponding directly to the HASH array passed as the
       single argument, or one created by associating the resulting variable values to the parameter names
       associated with the variable names.

html_formats

         ($prefixes,$suffixes) = html_formats \@html_formats;

       The html_format function takes an array reference of HTML formatting elements \@html_formats, and builds
       two arrays of strings: the first: $prefixes, is an array of prefixes containing the corresponding HTML
       formatting elements from \@html_formats, and the second, $suffixes, containing the appropriate HTML
       closing elements, in the opposite order.

       The result is designed to be used as prefixes and suffixes for the corresponding titles and column
       values.

       The array \@html_formats contains lists of HTML formatting elements, one for each column (either title or
       data).  Each array element is a list of one or more HTML elements, either given in HTML syntax, or as a
       "plain" name (ie: given as "\<ELEMENT\"> or plainly, "ELEMENT").  Multiple elements are separated by a
       comma ','.

       The resulting array of $prefixes contains the corresponding opening elements, in the order given, with
       the proper HTML element syntax.  The resulting array of $suffixes contains the closing elements, in the
       opposite order given, with the proper HTML element syntax.

       For example, if \@html_formats contains the two elements:

           [ 'FONT SIZE=+2,BOLD', 'FONT COLOR=red,EM' ]

       then the resulting two arrays will be returned as:

           [ [ '<FONT SIZE=+2><BOLD>', '<FONT COLOR=red><EM>' ],
             [ '</FONT></BOLD>',       '</FONT></EM>' ] ]

calc_widths

         ($num_cols, $widths, $precision, $max_widths) =   &calc_widths( $widthspec, $titles, $rewindable,
             $row_sub, $fmt_sub, $types, $showmode,       $max_width);

   DESCRIPTION
       calc_widths is a generalized subroutine used by all the ShowTable variant subroutines to setup internal
       variables prior to formatting for display.  Calc_widths handles the column width and precision analysis,
       including scanning the data (if rewindable) for appropriate default values.

       The number of columns in the data is returned, as well as three arrays: the declared column widths, the
       column precision values, and the maximum column widths.

   RETURN VALUES
       $num_cols is the number of columns in the data.  If the data is not rewindable, this is computed as the
                 maximum of the number of elements in the $widthspec array and the number of elements in the
                 $titles array.  When the data is rewindable, this is the maximum of the number of columns of
                 each row of data.

       $widths   is the column widths array ref, without the precision specs (if any).  Each column's width
                 value is determined by the original $widthspec value and/or the maximum length of the formatted
                 data for the column.

       $precision
                 is the precision component (if any) of the original $widthspec array ref.  If there was no
                 original precision component from the $widthspec, and the data is rewindable, then the data is
                 examined to determine the maximum default precision.

       $max_widths
                 is the ref to the array of maximum widths for the given columns.

   ARGUMENTS
       $widthspec
                 A reference to an array of column width (or length) values, each given as an integer, real
                 number, or a string value of "width.precision".  If a value is zero or null, the length of the
                 corresponding formatted data (if rewindable) and column title length are used to determine a
                 reasonable default.

                 If a column's width portion is a positive, non-zero number, then the column will be this wide,
                 regardless of the values lengths of the data in the column.

                 If the column's width portion is given as a negative number, then the positive value is used as
                 a minimum column width, with no limit on the maximum column width.  In other words, the column
                 will be at least width characters wide.

                 If the data is not rewindable, and a column's width value is null or zero, then the length of
                 the column title is used.  This may cause severe wrapping of data in the column, if the column
                 data lengths are much greater than the column title widths.

       $titles   The array ref to the column titles; used to determine the minimum acceptable width, as well as
                 the default number of columns.  If the $titles array is empty, then the $widthspec array is
                 used to determine the default number of columns.

       $rewindable
                 A flag indicating whether or not the data being formatted is rewindable.  If this is true, a
                 pass over the data will be done in order to calculate the maximum lengths of the actual
                 formatted data, using $fmt_sub (below), rather than just rely on the declared column lengths.
                 This allows for optimal column width adjustments (ie: the actual column widths may be less than
                 the declared column widths).

                 If it is not desired to have the column widths dynamically adjusted, then set the $rewindable
                 argument to 0, even if the data is rewindable.

       $row_sub  The code reference to the subroutine which returns the data; invoked only if $rewindable is
                 non-null.

       $fmt_sub  The subroutine used to determine the length of the data when formatted; if this is omitted or
                 null, the length of the data is used by default.  The $fmt_sub is used only when the data is
                 rewindable.

       $types    An array reference to the types of each of the value columns; used only when $fmt_sub is
                 invoked.

       $showmode A string indicating the mode of the eventual display; one of four strings: ""box"", ""table"",
                 ""list"", and ""html"".  Used to adjust widths for formatting requirements.

       $max_width
                 The maximum width of the table being formatted.  If set, and the total sum of the individual
                 columns exceeds this value, the column widths are scaled down uniformly.  If not set (null), no
                 column width scaling is done.

putcell

         $wrapped = &putcell( \@cells, $c, $cell_width, \@prefix, \@suffix, $wrap_flag );

       Output the contents of an array cell at $cell[$c], causing text longer than $cell_width to be saved for
       output on subsequent calls.  Prefixing the output of each cell's value is a string from the two-element
       array @prefix.  Suffixing each cell's value is a string from the two-element array @suffix.  The first
       element of either array is selected when $wrap_flag is zero or null, or when there is no more text in the
       current to be output.  The second element is selected when $wrap_flag is non-zero, and when there is more
       text in the current cell to be output.

       In the case of text longer than $cell_width, a non-zero value is returned.

       Cells with undefined data are not output, nor are the prefix or suffix strings.

center

       Center a string within a given width.

         $field = center $string, $width;

max

       Compute the maximum value from a list of values.

         $max = &max( @values );

min

       Compute the minum value from a list of values.

         $min = &min( @values );

max_length

       Compute the maximum length of a set of strings in an array reference.

         $maxlength = &max_length( \@array_ref );

htmltext

       Translate regular text for output into an HTML document.  This means certain characters, such as "&",
       ">", and "<" must be escaped.

         $output = &htmltext( $input [, $allflag ] );

       If $allflag is non-zero, then all characters are escaped.  Normally, only the four HTML syntactic break
       characters are escaped.

out

       Print text followed by a newline.

         out $fmt [, @text ];

put

       Print text (without a trailing newline).

         out $fmt [, @text ];

AUTHOR

       Alan K. Stebbens <aks@stebbens.org>

BUGS

       •         Embedded HTML is how the user can insert formatting overrides.  However, the HTML formatting
                 techniques have not been given much consideration -- feel free to provide constructive
                 feedback.