strfmon(3p) — Linux manual page


STRFMON(3P)             POSIX Programmer's Manual            STRFMON(3P)

PROLOG         top

       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         top

       strfmon, strfmon_l — convert monetary value to a string

SYNOPSIS         top

       #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         top

       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.

       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

               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         top

       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         top

       These functions shall fail if:

       E2BIG  Conversion stopped due to lack of space in the buffer.

       The following sections are informative.

EXAMPLES         top

       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

           %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
                      [ $*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().



RATIONALE         top



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

SEE ALSO         top

       fprintf(3p), localeconv(3p)

       The Base Definitions volume of POSIX.1‐2017, monetary.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic
       form from IEEE Std 1003.1-2017, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The
       Open Group Base Specifications Issue 7, 2018 Edition, Copyright
       (C) 2018 by the Institute of Electrical and Electronics
       Engineers, Inc and The Open Group.  In the event of any
       discrepancy between this version and the original IEEE and The
       Open Group Standard, the original IEEE and The Open Group
       Standard is the referee document. The original Standard can be
       obtained online at .

       Any typographical or formatting errors that appear in this page
       are most likely to have been introduced during the conversion of
       the source files to man page format. To report such errors, see .

IEEE/The Open Group               2017                       STRFMON(3P)

Pages that refer to this page: langinfo.h(0p)monetary.h(0p)fprintf(3p)setlocale(3p)