strfmon(3S)strfmon(3S)NAMEstrfmon - convert monetary value to string
SYNOPSIS
#include <monetary.h>
ssize_t strfmon(const char *s, size_t maxsize, const char *format, ...);
DESCRIPTIONstrfmon places 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 that contains two types of objects:
plain characters, which are simply copied to the output stream, and
conversion specifications, each of which results 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.
A conversion specification consists of the following sequence:
-- a % character
-- optional flags
-- optional field width
-- optional left precision
-- optional right precision
-- a required conversion character that determines the conversion to be
performed.
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. The fill character must be
representable in a single byte in order to work with precision
and width counts. The default numeric fill character is the
space character. This flag does not affect field width filling
which always uses the space character. 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.
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+ 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 the U.S.A.: 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 all fields are
left-justified (padded to the right) rather than right-
justified.
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 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 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.
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Conversion Characters
The conversion characters and their meanings are:
i The double argument is formatted according to the locale's
international currency format (for example, in the U.S.A.: USD
1,234.56).
n The double argument is formatted according to the locale's national
currency format (for example, in the U.S.A.: $1,234.56).
% Convert to a %; no argument is converted. The entire conversion
specification must be %%.
Locale Information
The LC_MONETARY category of the program's locale affects the behaviour 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:
1987 standard.
The monetary formatting information being unavailable in the POSIX
locale, the result is undefined.
RETURN VALUE
If the total number of resulting bytes including the terminating null
byte is not more than maxsize, strfmon returns the number of bytes placed
into the array pointed to by s, not including the terminating null byte.
Otherwise, -1 is returned, the contents of the array are indeterminate,
and errno is set to indicate the error.
ERRORSstrfmon will fail if:
[E2BIG] Conversion stopped due to lack of space in the buffer.
SEE ALSOlocaleconv().
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