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, ...);
- 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
- 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.
- 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.
- 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.
- 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.
- 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.
- 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 %%.
- Conversion stopped due to lack of space in the buffer.
%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]