The GNU C Library - Sign of Money Amount

Printing the Sign of an Amount of Money

These members of the struct lconv structure specify how to print the sign (if any) in a monetary value.

char *positive_sign

char *negative_sign

These are strings used to indicate positive (or zero) and negative (respectively) monetary quantities.

In the standard `C' locale, both of these members have a value of "" (the empty string), meaning ``unspecified''.

The ANSI standard doesn't say what to do when you find this value; we recommend printing positive_sign as you find it, even if it is empty. For a negative value, print negative_sign as you find it unless both it and positive_sign are empty, in which case print `-' instead. (Failing to indicate the sign at all seems rather unreasonable.)

char p_sign_posn

char n_sign_posn

These members have values that are small integers indicating how to position the sign for nonnegative and negative monetary quantities, respectively. (The string used by the sign is what was specified with positive_sign or negative_sign .) The possible values are as follows:

0

The currency symbol and quantity should be surrounded by parentheses.

1

Print the sign string before the quantity and currency symbol.

2

Print the sign string after the quantity and currency symbol.

3

Print the sign string right before the currency symbol.

4

Print the sign string right after the currency symbol.

CHAR_MAX

``Unspecified''. Both members have this value in the standard `C' locale.

The ANSI standard doesn't say what you should do when the value is CHAR_MAX . We recommend you print the sign after the currency symbol.

It is not clear whether you should let these members apply to the international currency format or not. POSIX says you should, but intuition plus the examples in the ANSI C standard suggest you should not. We hope that someone who knows well the conventions for formatting monetary quantities will tell us what we should recommend.