oracular (3) Number::Format.3pm.gz
NAME
Number::Format - Perl extension for formatting numbers
SYNOPSIS
use Number::Format;
my $x = new Number::Format %args;
$formatted = $x->round($number, $precision);
$formatted = $x->format_number($number, $precision, $trailing_zeroes);
$formatted = $x->format_negative($number, $picture);
$formatted = $x->format_picture($number, $picture);
$formatted = $x->format_price($number, $precision, $symbol);
$formatted = $x->format_bytes($number, $precision);
$number = $x->unformat_number($formatted);
use Number::Format qw(:subs);
$formatted = round($number, $precision);
$formatted = format_number($number, $precision, $trailing_zeroes);
$formatted = format_negative($number, $picture);
$formatted = format_picture($number, $picture);
$formatted = format_price($number, $precision, $symbol);
$formatted = format_bytes($number, $precision);
$number = unformat_number($formatted);
REQUIRES
Perl, version 5.8 or higher.
POSIX.pm to determine locale settings.
Carp.pm is used for some error reporting.
DESCRIPTION
These functions provide an easy means of formatting numbers in a manner suitable for displaying to the
user.
There are two ways to use this package. One is to declare an object of type Number::Format, which you
can think of as a formatting engine. The various functions defined here are provided as object methods.
The constructor "new()" can be used to set the parameters of the formatting engine. Valid parameters
are:
THOUSANDS_SEP - character inserted between groups of 3 digits
DECIMAL_POINT - character separating integer and fractional parts
MON_THOUSANDS_SEP - like THOUSANDS_SEP, but used for format_price
MON_DECIMAL_POINT - like DECIMAL_POINT, but used for format_price
INT_CURR_SYMBOL - character(s) denoting currency (see format_price())
DECIMAL_DIGITS - number of digits to the right of dec point (def 2)
DECIMAL_FILL - boolean; whether to add zeroes to fill out decimal
NEG_FORMAT - format to display negative numbers (def ``-x'')
KILO_SUFFIX - suffix to add when format_bytes formats kilobytes (trad)
MEGA_SUFFIX - " " " " " " megabytes (trad)
GIGA_SUFFIX - " " " " " " gigabytes (trad)
KIBI_SUFFIX - suffix to add when format_bytes formats kibibytes (iec)
MEBI_SUFFIX - " " " " " " mebibytes (iec)
GIBI_SUFFIX - " " " " " " gibibytes (iec)
They may be specified in upper or lower case, with or without a leading hyphen ( - ).
If "THOUSANDS_SEP" is set to the empty string, format_number will not insert any separators.
The defaults for "THOUSANDS_SEP", "DECIMAL_POINT", "MON_THOUSANDS_SEP", "MON_DECIMAL_POINT", and
"INT_CURR_SYMBOL" come from the POSIX locale information (see perllocale). If your POSIX locale does not
provide "MON_THOUSANDS_SEP" and/or "MON_DECIMAL_POINT" fields, then the "THOUSANDS_SEP" and/or
"DECIMAL_POINT" values are used for those parameters. Formerly, POSIX was optional but this caused
problems in some cases, so it is now required. If this causes you hardship, please contact the author of
this package at <SwPrAwM@cpan.org> (remove "SPAM" to get correct email address) for help.
If any of the above parameters are not specified when you invoke "new()", then the values are taken from
package global variables of the same name (e.g. $DECIMAL_POINT is the default for the "DECIMAL_POINT"
parameter). If you use the ":vars" keyword on your "use Number::Format" line (see non-object-oriented
example below) you will import those variables into your namesapce and can assign values as if they were
your own local variables. The default values for all the parameters are:
THOUSANDS_SEP = ','
DECIMAL_POINT = '.'
MON_THOUSANDS_SEP = ','
MON_DECIMAL_POINT = '.'
INT_CURR_SYMBOL = 'USD'
DECIMAL_DIGITS = 2
DECIMAL_FILL = 0
NEG_FORMAT = '-x'
KILO_SUFFIX = 'K'
MEGA_SUFFIX = 'M'
GIGA_SUFFIX = 'G'
KIBI_SUFFIX = 'KiB'
MEBI_SUFFIX = 'MiB'
GIBI_SUFFIX = 'GiB'
Note however that when you first call one of the functions in this module without using the object-
oriented interface, further setting of those global variables will have no effect on non-OO calls. It is
recommended that you use the object-oriented interface instead for fewer headaches and a cleaner design.
The "DECIMAL_FILL" and "DECIMAL_DIGITS" values are not set by the Locale system, but are definable by the
user. They affect the output of "format_number()". Setting "DECIMAL_DIGITS" is like giving that value
as the $precision argument to that function. Setting "DECIMAL_FILL" to a true value causes
"format_number()" to append zeroes to the right of the decimal digits until the length is the specified
number of digits.
"NEG_FORMAT" is only used by "format_negative()" and is a string containing the letter 'x', where that
letter will be replaced by a positive representation of the number being passed to that function.
"format_number()" and "format_price()" utilize this feature by calling "format_negative()" if the number
was less than 0.
"KILO_SUFFIX", "MEGA_SUFFIX", and "GIGA_SUFFIX" are used by "format_bytes()" when the value is over 1024,
1024*1024, or 1024*1024*1024, respectively. The default values are "K", "M", and "G". These apply in
the default "traditional" mode only. Note: TERA or higher are not implemented because of integer
overflows on 32-bit systems.
"KIBI_SUFFIX", "MEBI_SUFFIX", and "GIBI_SUFFIX" are used by "format_bytes()" when the value is over 1024,
1024*1024, or 1024*1024*1024, respectively. The default values are "KiB", "MiB", and "GiB". These apply
in the "iso60027"" mode only. Note: TEBI or higher are not implemented because of integer overflows on
32-bit systems.
The only restrictions on "DECIMAL_POINT" and "THOUSANDS_SEP" are that they must not be digits and must
not be identical. There are no restrictions on "INT_CURR_SYMBOL".
For example, a German user might include this in their code:
use Number::Format;
my $de = new Number::Format(-thousands_sep => '.',
-decimal_point => ',',
-int_curr_symbol => 'DEM');
my $formatted = $de->format_number($number);
Or, if you prefer not to use the object oriented interface, you can do this instead:
use Number::Format qw(:subs :vars);
$THOUSANDS_SEP = '.';
$DECIMAL_POINT = ',';
$INT_CURR_SYMBOL = 'DEM';
my $formatted = format_number($number);
EXPORTS
Nothing is exported by default. To export the functions or the global variables defined herein, specify
the function name(s) on the import list of the "use Number::Format" statement. To export all functions
defined herein, use the special tag ":subs". To export the variables, use the special tag ":vars"; to
export both subs and vars you can use the tag ":all".
METHODS
new( %args )
Creates a new Number::Format object. Valid keys for %args are any of the parameters described above.
Keys may be in all uppercase or all lowercase, and may optionally be preceded by a hyphen (-)
character. Example:
my $de = new Number::Format(-thousands_sep => '.',
-decimal_point => ',',
-int_curr_symbol => 'DEM');
round($number, $precision)
Rounds the number to the specified precision. If $precision is omitted, the value of the
"DECIMAL_DIGITS" parameter is used (default value 2). Both input and output are numeric (the
function uses math operators rather than string manipulation to do its job), The value of $precision
may be any integer, positive or negative. Examples:
round(3.14159) yields 3.14
round(3.14159, 4) yields 3.1416
round(42.00, 4) yields 42
round(1234, -2) yields 1200
Since this is a mathematical rather than string oriented function, there will be no trailing zeroes
to the right of the decimal point, and the "DECIMAL_POINT" and "THOUSANDS_SEP" variables are ignored.
To format your number using the "DECIMAL_POINT" and "THOUSANDS_SEP" variables, use "format_number()"
instead.
format_number($number, $precision, $trailing_zeroes)
Formats a number by adding "THOUSANDS_SEP" between each set of 3 digits to the left of the decimal
point, substituting "DECIMAL_POINT" for the decimal point, and rounding to the specified precision
using "round()". Note that $precision is a maximum precision specifier; trailing zeroes will only
appear in the output if $trailing_zeroes is provided, or the parameter "DECIMAL_FILL" is set, with a
value that is true (not zero, undef, or the empty string). If $precision is omitted, the value of
the "DECIMAL_DIGITS" parameter (default value of 2) is used.
If the value is too large or great to work with as a regular number, but instead must be shown in
scientific notation, returns that number in scientific notation without further formatting.
Examples:
format_number(12345.6789) yields '12,345.68'
format_number(123456.789, 2) yields '123,456.79'
format_number(1234567.89, 2) yields '1,234,567.89'
format_number(1234567.8, 2) yields '1,234,567.8'
format_number(1234567.8, 2, 1) yields '1,234,567.80'
format_number(1.23456789, 6) yields '1.234568'
format_number("0.000020000E+00", 7);' yields '2e-05'
Of course the output would have your values of "THOUSANDS_SEP" and "DECIMAL_POINT" instead of ',' and
'.' respectively.
format_negative($number, $picture)
Formats a negative number. Picture should be a string that contains the letter "x" where the number
should be inserted. For example, for standard negative numbers you might use ``"-x"'', while for
accounting purposes you might use ``"(x)"''. If the specified number begins with a ``-'' character,
that will be removed before formatting, but formatting will occur whether or not the number is
negative.
format_picture($number, $picture)
Returns a string based on $picture with the "#" characters replaced by digits from $number. If the
length of the integer part of $number is too large to fit, the "#" characters are replaced with
asterisks ("*") instead. Examples:
format_picture(100.023, 'USD ##,###.##') yields 'USD 100.02'
format_picture(1000.23, 'USD ##,###.##') yields 'USD 1,000.23'
format_picture(10002.3, 'USD ##,###.##') yields 'USD 10,002.30'
format_picture(100023, 'USD ##,###.##') yields 'USD **,***.**'
format_picture(1.00023, 'USD #.###,###') yields 'USD 1.002,300'
The comma (,) and period (.) you see in the picture examples should match the values of
"THOUSANDS_SEP" and "DECIMAL_POINT", respectively, for proper operation. However, the
"THOUSANDS_SEP" characters in $picture need not occur every three digits; the only use of that
variable by this function is to remove leading commas (see the first example above). There may not
be more than one instance of "DECIMAL_POINT" in $picture.
The value of "NEG_FORMAT" is used to determine how negative numbers are displayed. The result of
this is that the output of this function my have unexpected spaces before and/or after the number.
This is necessary so that positive and negative numbers are formatted into a space the same size. If
you are only using positive numbers and want to avoid this problem, set NEG_FORMAT to "x".
format_price($number, $precision, $symbol)
Returns a string containing $number formatted similarly to "format_number()", except that the decimal
portion may have trailing zeroes added to make it be exactly $precision characters long, and the
currency string will be prefixed.
The $symbol attribute may be one of "INT_CURR_SYMBOL" or "CURRENCY_SYMBOL" (case insensitive) to use
the value of that attribute of the object, or a string containing the symbol to be used. The default
is "INT_CURR_SYMBOL" if this argument is undefined or not given; if set to the empty string, or if
set to undef and the "INT_CURR_SYMBOL" attribute of the object is the empty string, no currency will
be added.
If $precision is not provided, the default of 2 will be used. Examples:
format_price(12.95) yields 'USD 12.95'
format_price(12) yields 'USD 12.00'
format_price(12, 3) yields '12.000'
The third example assumes that "INT_CURR_SYMBOL" is the empty string.
format_bytes($number, %options)
format_bytes($number, $precision) # deprecated
Returns a string containing $number formatted similarly to "format_number()", except that large
numbers may be abbreviated by adding a suffix to indicate 1024, 1,048,576, or 1,073,741,824 bytes.
Suffix may be the traditional K, M, or G (default); or the IEC standard 60027 "KiB," "MiB," or "GiB"
depending on the "mode" option.
Negative values will result in an error.
The second parameter can be either a hash that sets options, or a number. Using a number here is
deprecated and will generate a warning; early versions of Number::Format only allowed a numeric
value. A future release of Number::Format will change this warning to an error. New code should use
a hash instead to set options. If it is a number this sets the value of the "precision" option.
Valid options are:
precision
Set the precision for displaying numbers. If not provided, a default of 2 will be used.
Examples:
format_bytes(12.95) yields '12.95'
format_bytes(12.95, precision => 0) yields '13'
format_bytes(2048) yields '2K'
format_bytes(2048, mode => "iec") yields '2KiB'
format_bytes(9999999) yields '9.54M'
format_bytes(9999999, precision => 1) yields '9.5M'
unit
Sets the default units used for the results. The default is to determine this automatically in
order to minimize the length of the string. In other words, numbers greater than or equal to
1024 (or other number given by the 'base' option, q.v.) will be divided by 1024 and $KILO_SUFFIX
or $KIBI_SUFFIX added; if greater than or equal to 1048576 (1024*1024), it will be divided by
1048576 and $MEGA_SUFFIX or $MEBI_SUFFIX appended to the end; etc.
However if a value is given for "unit" it will use that value instead. The first letter (case-
insensitive) of the value given indicates the threshhold for conversion; acceptable values are G
(for giga/gibi), M (for mega/mebi), K (for kilo/kibi), or A (for automatic, the default). For
example:
format_bytes(1048576, unit => 'K') yields '1,024K'
instead of '1M'
Note that the valid values to this option do not vary even when the suffix configuration
variables have been changed.
base
Sets the number at which the $KILO_SUFFIX is added. Default is 1024. Set to any value; the only
other useful value is probably 1000, as hard disk manufacturers use that number to make their
disks sound bigger than they really are.
If the mode (see below) is set to "iec" or "iec60027" then setting the base option results in an
error.
mode
Traditionally, bytes have been given in SI (metric) units such as "kilo" and "mega" even though
they represent powers of 2 (1024, etc.) rather than powers of 10 (1000, etc.) This "binary
prefix" causes much confusion in consumer products where "GB" may mean either 1,048,576 or
1,000,000, for example. The International Electrotechnical Commission has created standard IEC
60027 to introduce prefixes Ki, Mi, Gi, etc. ("kibibytes," "mebibytes," "gibibytes," etc.) to
remove this confusion. Specify a mode option with either "traditional" or "iec60027" (or
abbreviate as "trad" or "iec") to indicate which type of binary prefix you want format_bytes to
use. For backward compatibility, "traditional" is the default. See
http://en.wikipedia.org/wiki/Binary_prefix for more information.
unformat_number($formatted)
Converts a string as returned by "format_number()", "format_price()", or "format_picture()", and
returns the corresponding value as a numeric scalar. Returns "undef" if the number does not contain
any digits. Examples:
unformat_number('USD 12.95') yields 12.95
unformat_number('USD 12.00') yields 12
unformat_number('foobar') yields undef
unformat_number('1234-567@.8') yields 1234567.8
The value of "DECIMAL_POINT" is used to determine where to separate the integer and decimal portions
of the input. All other non-digit characters, including but not limited to "INT_CURR_SYMBOL" and
"THOUSANDS_SEP", are removed.
If the number matches the pattern of "NEG_FORMAT" or there is a ``-'' character before any of the
digits, then a negative number is returned.
If the number ends with the "KILO_SUFFIX", "KIBI_SUFFIX", "MEGA_SUFFIX", "MEBI_SUFFIX",
"GIGA_SUFFIX", or "GIBI_SUFFIX" characters, then the number returned will be multiplied by the
appropriate multiple of 1024 (or if the base option is given, by the multiple of that value) as
appropriate. Examples:
unformat_number("4K", base => 1024) yields 4096
unformat_number("4K", base => 1000) yields 4000
unformat_number("4KiB", base => 1024) yields 4096
unformat_number("4G") yields 4294967296
CAVEATS
Some systems, notably OpenBSD, may have incomplete locale support. Using this module together with
setlocale(3) in OpenBSD may therefore not produce the intended results.
BUGS
No known bugs at this time. Report bugs using the CPAN request tracker at
<https://rt.cpan.org/NoAuth/Bugs.html?Dist=Number-Format> or by email to the author.
AUTHOR
William R. Ward, SwPrAwM@cpan.org (remove "SPAM" before sending email, leaving only my initials)
SEE ALSO
perl(1).