fatomoney - convert ASCII to MONEY value
#include
int fatomoney (sptr, format, m, size)
char *sptr;
char *format;
MONEY *m;
int size;
Fatomoney converts a string pointed to by sptr to a MONEY value
using format to control the conversion. The result of the
conversion is stored in the MONEY value pointed at by m. Size is
the size of the MONEY value. Fatomoney supports both double and
float values.Size must be the size of a double or the size of a
float.
Fatomoney first tries to convert sptr using format. If this
fails, fatomoney applies the standard input rules for MONEY
values. These rules allow an optional string of tabs or spaces,
an optional minus sign, and a string of digits optionally
containing a decimal separator character (returned by
getfdec(C-3)). The string may also
contain one or more of the
thousands separator character (returned by getfthou(C-3))
to make
the number more readable.
If sptr does not have a decimal separator character, the number
of implied decimal places is the value returned by getfplac(C-3).
Once the decimal separator has been positioned, the value is
converted in the basic unit of currency for the defined country
(pennies for U.S.A.).
Fractions of the basic unit of currency are accepted although
small errors in representation can occur if much arithmetic is
done with fractional values. Because of the method fatomoney uses
to convert a string, there can never be representation errors
with values that do not contain a fraction of the basic unit.
A MONEY value can represent values that contain 15 significant
digits. This allows accurate representation of dollar values up
to 10 trillion dollars. This number may be different for other
country formats (depending on the value returned by
getfplac(C-3)).
The first unrecognizable character ends the string. When doing
edit checks, it is left to the calling program to determine if
the remaining unrecognized characters should be considered valid.
fcountry(C-3), getfmoney(C-3),
getfdec(C-3), getfthou(C-3),
getfplac(C-3), atomoney(C-3),
round(C-3)
C/Base Reference Manual Chapter 13, "Formatting Data Values"
DIAGNOSTICS
If an error occurs, fatomoney returns a negative number and the
contents of m are undefined. The following symbolic error codes
are defined in
FTOOBIG size is not the size of a double or float
value (use sizeof function) or the result
overflowed
FFORMAT format is invalid
FIFORMAT sptr does not conform to any of the
formatting rules
Fatomoney defines overflow to mean a number with more than 15
digits to the left of the decimal point for double values, and
more than 6 digits to the left of the decimal point for float
values.
Internally, MONEY values are kept as a whole number of the basic
unit of currency. For example, in the U.S.A., the basic unit of
currency is the penny. In this case, all MONEY amounts are kept
as the number of pennies. This representation guarantees accurate
representation of any money amount.
When a value is being converted, the decimal separator is located
(or implied) and moved left or right based on the value returned
by getfplac(C-3). For example, if
a string of 1.00 is entered for
a U.S.A. MONEY value, the decimal separator (.) is moved right
two places (100.) before the number is converted. The end result
is a number of the basic units (100 pennies). This method
guarantees that there is no round-off error when converting the
string to a floating point value.