gcvt

Syntax

#include <stdlib.h> char * gcvt (double value, int ndigits, char *buf)

Description

This function converts its argument value into a null-terminated string of ndigits significant digits in buf. buf should have enough space to hold at least ndigits + 7 characters. The result roughly corresponds to what is obtained by the following snippet:

(void) sprintf(buf, "%.*g", ndigits, value);

except that trailing zeros and trailing decimal point are suppressed.

The least-significant digit in buf is rounded.

ecvtbuf produces the string "NaN" if value is a NaN, and "Inf" if value is an infinity.

Return Value

A pointer to buf.

Portability

ANSI/ISO C	No
POSIX	No

Example

#include <stdlib.h> #include <stdio.h> #include <math.h> char vbuf[20]; /* This will print " 3.14159". */ printf ("%s", gcvt (M_PI, 5, buf));