# strfmon

## 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.
    


## NAME



           strfmon, strfmon_l — convert monetary value to a string
    


## 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_ , ...);
    


## 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.
    


## 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.
    


## ERRORS



           These functions shall fail if:
    
           **E2BIG** Conversion stopped due to lack of space in the buffer.
    
           _The following sections are informative._
    


## 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_().
    


## APPLICATION USAGE



           None.
    


## RATIONALE



           None.
    


## FUTURE DIRECTIONS



           Lowercase conversion characters are reserved for future standards
           use and uppercase for implementation-defined use.
    


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