fcvt

Converts its argument to a null-terminated string of ASCII digits and returns the address of the string. The string is stored in a thread-specific location created by the DEC C RTL.

Format

#include  <stdlib.h>

char *fcvt  (double value, int ndigits, int
            *decpt, int *sign);

Arguments

value
An object of type double that is converted to a null-terminated string of ASCII digits.
ndigits
The number of ASCII digits after the decimal point to be used in the converted string.
decpt
The position of the decimal point relative to the first character in the returned string. The returned string does not contain the actual decimal point. A negative int value means that the decimal point is decpt number of spaces to the left of the returned digits (the spaces are filled with zeros). A 0 value means that the decimal point is immediately to the left of the first digit in the returned string.
sign
An integer value that indicates whether the value argument is positive or negative. If value is negative, the fcvt function places a nonzero value at the address specified by sign. Otherwise, the functions assign 0 to the address specified by sign.

Description

This function converts value to a null-terminated string and returns a pointer to it. The resulting low-order digit is rounded to the correct digit for outputting ndigits digits in C F-format. The decpt argument is assigned the position of the decimal point relative to the first character in the string.

In C F-format, ndigits is the number of digits desired after the decimal point. Very large numbers produce a very long string of digits before the decimal point, and ndigit of digits after the decimal point. For large numbers, it is preferable to use the gcvt or ecvt function so that E-format is used.

Repeated calls to the fcvt function overwrite any existing string.

The ecvt, fcvt, and gcvt functions represent the following special values specified in the IEEE Standard for floating-point arithmetic:
Value  Representation 
Quiet NaN  NaNQ 
Signalling NaN  NaNS 
+Infinity  Infinity 
- Infinity  -Infinity 

The sign associated with each of these values is stored into the sign argument. In IEEE floating-point representation, a value of 0 (zero) can be positive or negative, as set by the sign argument.

See also gcvt and ecvt in this section.

Return Value
A pointer to the converted string. 


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