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

not ANSI, not POSIX

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));

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