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) ; |
The ecvt
() function converts
number
to a
null-terminated string of ndigits
digits (where
ndigits
is reduced to
an system-specific limit determined by the precision of a
double), and returns a pointer to the string. The high-order
digit is non-zero, 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 non-zero value, otherwise it's 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.
Both the ecvt
() and
fcvt
() functions return a
pointer to a static string containing the ASCII
representation of number
. The static string is
overwritten by each call to ecvt
() or fcvt
().
These functions are obsolete. Instead, sprintf(3) is recommended.
Linux libc4 and libc5 specified the type of ndigits
as size_t
. Not all locales use a
point as the radix character (`decimal point').
ecvt_r(3), gcvt(3), qecvt(3), setlocale(3), sprintf(3)
|