преобразовать денежное значение в строку (convert monetary value to a string)
Пролог (Prolog)
This manual page is part of the POSIX Programmer's Manual. The
Linux implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
Имя (Name)
strfmon, strfmon_l — convert monetary value to a string
Синопсис (Synopsis)
#include <monetary.h>
ssize_t strfmon(char *restrict s, size_t maxsize,
const char *restrict format, ...);
ssize_t strfmon_l(char *restrict s, size_t maxsize,
locale_t locale, const char *restrict format, ...);
Описание (Description)
The strfmon() function shall place characters into the array
pointed to by s as controlled by the string pointed to by format.
No more than maxsize bytes are placed into the array.
The format is a character string, beginning and ending in its
initial state, if any, that contains two types of objects: plain
characters, which are simply copied to the output stream, and
conversion specifications, each of which shall result in the
fetching of zero or more arguments which are converted and
formatted. The results are undefined if there are insufficient
arguments for the format. If the format is exhausted while
arguments remain, the excess arguments are simply ignored.
The application shall ensure that a conversion specification
consists of the following sequence:
* A '%' character
* Optional flags
* Optional field width
* Optional left precision
* Optional right precision
* A required conversion specifier character that determines the
conversion to be performed
The strfmon_l() function shall be equivalent to the strfmon()
function, except that the locale data used is from the locale
represented by locale.
Flags
One or more of the following optional flags can be specified to
control the conversion:
=f An '=' followed by a single character f which is used as
the numeric fill character. In order to work with
precision or width counts, the fill character shall be a
single byte character; if not, the behavior is undefined.
The default numeric fill character is the <space>. This
flag does not affect field width filling which always
uses the <space>. This flag is ignored unless a left
precision (see below) is specified.
^ Do not format the currency amount with grouping
characters. The default is to insert the grouping
characters if defined for the current locale.
+ or ( Specify the style of representing positive and negative
currency amounts. Only one of '+' or '(' may be
specified. If '+' is specified, the locale's equivalent
of '+' and '-' are used (for example, in many locales,
the empty string if positive and '-' if negative). If '('
is specified, negative amounts are enclosed within
parentheses. If neither flag is specified, the '+' style
is used.
! Suppress the currency symbol from the output conversion.
- Specify the alignment. If this flag is present the result
of the conversion is left-justified (padded to the right)
rather than right-justified. This flag shall be ignored
unless a field width (see below) is specified.
Field Width
w A decimal digit string w specifying a minimum field width
in bytes in which the result of the conversion is right-
justified (or left-justified if the flag '-' is
specified). The default is 0.
Left Precision
#n A '#' followed by a decimal digit string n specifying a
maximum number of digits expected to be formatted to the
left of the radix character. This option can be used to
keep the formatted output from multiple calls to the
strfmon() function aligned in the same columns. It can
also be used to fill unused positions with a special
character as in "$***123.45". This option causes an
amount to be formatted as if it has the number of digits
specified by n. If more than n digit positions are
required, this conversion specification is ignored.
Digit positions in excess of those actually required are
filled with the numeric fill character (see the =f flag
above).
If grouping has not been suppressed with the '^' flag,
and it is defined for the current locale, grouping
separators are inserted before the fill characters (if
any) are added. Grouping separators are not applied to
fill characters even if the fill character is a digit.
To ensure alignment, any characters appearing before or
after the number in the formatted output such as currency
or sign symbols are padded as necessary with <space>
characters to make their positive and negative formats an
equal length.
Right Precision
.p A <period> followed by a decimal digit string p
specifying the number of digits after the radix
character. If the value of the right precision p is 0, no
radix character appears. If a right precision is not
included, a default specified by the current locale is
used. The amount being formatted is rounded to the
specified number of digits prior to formatting.
Conversion Specifier Characters
The conversion specifier characters and their meanings are:
i The double argument is formatted according to the
locale's international currency format (for example, in
the US: USD 1,234.56). If the argument is ±Inf or NaN,
the result of the conversion is unspecified.
n The double argument is formatted according to the
locale's national currency format (for example, in the
US: $1,234.56). If the argument is ±Inf or NaN, the
result of the conversion is unspecified.
% Convert to a '%'; no argument is converted. The entire
conversion specification shall be %%.
Locale Information
The LC_MONETARY category of the current locale affects the
behavior of this function including the monetary radix character
(which may be different from the numeric radix character affected
by the LC_NUMERIC category), the grouping separator, the currency
symbols, and formats. The international currency symbol should
be conformant with the ISO 4217:2001 standard.
If the value of maxsize is greater than {SSIZE_MAX}, the result
is implementation-defined.
The behavior is undefined if the locale argument to strfmon_l()
is the special locale object LC_GLOBAL_LOCALE or is not a valid
locale object handle.
Возвращаемое значение (Return value)
If the total number of resulting bytes including the terminating
null byte is not more than maxsize, these functions shall return
the number of bytes placed into the array pointed to by s, not
including the terminating NUL character. Otherwise, -1 shall be
returned, the contents of the array are unspecified, and errno
shall be set to indicate the error.
Ошибки (Error)
These functions shall fail if:
E2BIG Conversion stopped due to lack of space in the buffer.
The following sections are informative.
Примеры (Examples)
Given a locale for the US and the values 123.45, -123.45, and
3456.781, the following output might be produced. Square brackets
("[]") are used in this example to delimit the output.
%n [$123.45] Default formatting
[-$123.45]
[$3,456.78]
%11n [ $123.45] Right align within an 11-character field
[ -$123.45]
[ $3,456.78]
%#5n [ $ 123.45] Aligned columns for values up to 99999
[-$ 123.45]
[ $ 3,456.78]
%=*#5n [ $***123.45] Specify a fill character
[-$***123.45]
[ $*3,456.78]
%=0#5n [ $000123.45] Fill characters do not use grouping
[-$000123.45] even if the fill character is a digit
[ $03,456.78]
%^#5n [ $ 123.45] Disable the grouping separator
[-$ 123.45]
[ $ 3456.78]
%^#5.0n [ $ 123] Round off to whole units
[-$ 123]
[ $ 3457]
%^#5.4n [ $ 123.4500] Increase the precision
[-$ 123.4500]
[ $ 3456.7810]
%(#5n [ $ 123.45 ] Use an alternative pos/neg style
[($ 123.45)]
[ $ 3,456.78 ]
%!(#5n [ 123.45 ] Disable the currency symbol
[( 123.45)]
[ 3,456.78 ]
%-14#5.4n [ $ 123.4500 ] Left-justify the output
[-$ 123.4500 ]
[ $ 3,456.7810 ]
%14#5.4n [ $ 123.4500] Corresponding right-justified output
[ -$ 123.4500]
[ $ 3,456.7810]
See also the EXAMPLES section in fprintf().
Использование в приложениях (Application usage)
None.
Обоснование (Rationale)
None.
Будущие направления (Future directions)
Lowercase conversion characters are reserved for future standards
use and uppercase for implementation-defined use.
Смотри также (See also)
fprintf(3p), localeconv(3p)
The Base Definitions volume of POSIX.1‐2017, monetary.h(0p)
