Content-type: text/html Man page of strfmon


Section: C Library Functions (3)
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strfmon - Formats monetary strings  


Standard C Library (, libc.a)  


#include <monetary.h>

ssize_t strfmon(
        char *s,
        size_t maxsize,
        const char *format
        [,double value]...);  


Interfaces documented on this reference page conform to industry standards as follows:

strfmon(): XPG4

Refer to the standards(5) reference page for more information about industry standards and associated tags.  


Contains the output of the strfmon() function. Specifies the maximum number of bytes (including the null terminating byte) that may be placed in the s parameter. Contains characters and conversion specifications. Specifies the double data to be converted according to the format parameter.  


The strfmon() function converts numeric values to monetary strings according to the specifications in the format parameter. The function converts the double-precision floating-point value parameters under the control of the format parameter and stores the result in the array specified by the s parameter.

The format parameter is a character string that contains two types of objects: Literal characters, which are copied to the output stream. Conversion specifications, each of which causes zero or more items to be fetched from the value parameter list.

If there are insufficient parameters for the format parameter, the results are undefined. If parameters remain after the format parameter is exhausted, the excess parameters are ignored.  

Conversion Specifications

A conversion specification consists of a % (percent sign) character, optional flags, optional field width, optional left precision, optional right precision, and a required conversion character that determines the conversion to be performed.

Each conversion specification in the format parameter has the following syntax:

A % (percent sign). Zero or more optional flags can be specified to control the conversion. The flag characters and their meanings are as follows: An = (equal sign) followed by a single character that specifies the numeric fill character. 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 is specified. The ^ (circumflex) flag suppresses the grouping character when formatting the currency amount. The default is to group the digits and separate them with the grouping character if defined for the current locale. The + (plus) character specifies that the locale's equivalent of + and - are used to indicate positive and negative values. You cannot specify both the + (plus) character and the ( (left-parenthesis) character. If you specify neither, the style specified in the locale for + is used. The ( (left-parenthesis) character specifies that the locale's equivalent of enclosing negative amounts within parentheses is used to indicate positive and negative values. See also the description of the + character. The ! (exclamation mark) character suppresses the currency symbol from the output conversion. The - (hyphen) character specifies that the field is left justified within the minimum field width rather than right justified. This flag is ignored unless a minimum field width is specified. An optional decimal digit string w that specifies a minimum field width in which the result of the conversion is right justified. If the - (hyphen) flag is specified, the result is left justified. The default value for w is 0 (zero). An optional left precision consisting of a # (number sign), followed by a decimal digit string n. The decimal digit string specifies the maximum number of digits to be formatted to the left of the radix character. This option causes an amount to be formatted as if it has the number of digits specified by the n digit string. If more than n digit positions are required, this option is ignored. Digit positions in excess of those required are filled with the numeric fill character set with the =f flag. The #n option can be specified to keep the formatted output from multiple calls to the strfmon() function aligned in the same columns. The option can also be used in conjunction with the =f flag to fill unused positions with a special character (for example, $***123.45).

If grouping is defined for the current locale and has not been suppressed with the ^ (circumflex) flag, grouping separators are inserted before the fill characters (if any) are added. Therefore, grouping characters are not applied to instances of the fill character, even when the fill character is a digit. For the following example in which the fill character is zero, assume that the locale specifies that the thousands grouping character is a comma (,), that the grouping character should be delimit each group of three characters to the left of the radix character, and that the radix character is the period (.):
strcpy(format,"%=0#10i"); monetary_value = 1.23; retval = strfmon(str,STR_SIZE,format, monetary_value); printf("(%s,%f) => %s\en",format,monetary_value, str);
This example prints 0000000000001.23 rather than 0,000,000,001.23. An optional right precision consisting of a . (period) followed by a decimal digit string p that specifies the number of digits after the radix character. If the value of the p digit string is 0 (zero), no radix character is used. If a right precision is not specified, a default specified by the current locale is used. The amount being formatted is rounded to the specified number of digits prior to formatting. A character that indicates the type of conversion to be applied: No parameter is converted; the conversion specification %% (double percent sign) produces a single % in the output string. The double parameter is formatted according to the current locale's international currency format; for example, in a U.S. locale: USD 1,234.56. The double parameter is formatted according to the current locale's national currency format; for example, in a U.S. locale: $1,234.56.

The following table lists the default values used by the strfmon() function when there are no values defined in the locale for these members of the lconv structure. These are the defaults for the POSIX (C) locale. For all other lconv members, such as mon_thousands_sep, there are no defaults.

lconv StructureExplanationDefault Value

mon_decimal_pointRadix character. (period)

negative_signCharacter to indicate- (hyphen)
negative values

int_frac_digitsDefault right2
precision for %i

frac_digitsDefault right2
precision for %n

left_parenthesisCharacters used( (left parenthesis)
for ( flag

right_parenthesisCharacters used) (right parenthesis)
for ) flag



The following table lists conversion specifications and the output.

Conv.Output inOutput in
Spec.a US LocaleC LocaleExplanation

%n$100.35    100.35    Default
$1,225.15-    -1225.15    national format

%iUSD 100.35    100.35    Default
USD 1,225.15-    -1225.15    international format

%(#6.3n$ 9,876.543     9876.543    Explicit
($ 25,832.000)    ( 25832.000)    left and right
        precision with
        for negative values

%=*#7n$****4,379.25    ***4379.25    Fill
-$****4,379.25    -***4379.25    character

%=0#7n$0004,379.25    0004379.25    Zero fill
$0004,379.25-    -0004379.25    

%!.0n3,225    3225    Suppress
3,225-    -3225    currency symbol
        and round to



If successful, and if the number of resulting bytes (including the terminating null byte) is not more than the number of bytes specified by the maxsize parameter, the strfmon() function returns the number of bytes placed into the array pointed to by the s parameter. The terminating null byte is not included in the return count. Otherwise, the function returns -1, and the contents of the s array are indeterminate.  


If one of the following conditions occur, the strfmon() function sets errno to the corresponding value: The function is not supported. (This value may be returned on platforms, other than Tru64 UNIX, that conform to XPG4 but do not support its worldwide portability interfaces.) Conversion stopped due to lack of space in the buffer.  


Functions: localeconv(3), nl_langinfo(3), scanf(3), setlocale(3), strftime(3), wscanf(3)

Files: locale(4)

Others: i18n_intro(5), l10n_intro(5), standards(5)

Writing Software for the International Market delim off



Conversion Specifications

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Time: 02:40:45 GMT, October 02, 2010