ecvt, fcvt - convert a floating-point number to a string
#include <stdlib.h>
char *ecvt(double number
, int ndigits
, int *decpt
, int *sign
);
char *fcvt(double number
, int ndigits
, int *decpt
, int *sign
);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
The ecvt() function converts number
to a null-terminated string of ndigits
digits (where ndigits
is reduced to a system-specific limit determined by the precision of a double
), and returns a pointer to the string. The high-order digit is nonzero, unless number
is zero. The low order digit is rounded. The string itself does not contain a decimal point; however, the position of the decimal point relative to the start of the string is stored in *decpt
. A negative value for *decpt
means that the decimal point is to the left of the start of the string. If the sign of number
is negative, *sign
is set to a nonzero value, otherwise it is set to 0. If number
is zero, it is unspecified whether *decpt
is 0 or 1.
The fcvt() function is identical to ecvt(), except that ndigits
specifies the number of digits after the decimal point.