_ecvt

Converts a double number to a string.

char *_ecvt( double value, int count, int *dec, int *sign );

For additional compatibility information, see Compatibility in the Introduction.

Libraries

Return Value

_ecvt returns a pointer to the string of digits. There is no error return.

Parameters

value

Number to be converted

count

Number of digits stored

dec

Stored decimal-point position

sign

Sign of converted number

Remarks

The _ecvt function converts a floating-point number to a character string. The value parameter is the floating-point number to be converted. This function stores up to count digits of value as a string and appends a null character ('\0'). If the number of digits in value exceeds count, the low-order digit is rounded. If there are fewer than count digits, the string is padded with zeros.

Only digits are stored in the string. The position of the decimal point and the sign of value can be obtained from dec and sign after the call. The dec parameter points to an integer value giving the position of the decimal point with respect to the beginning of the string. A 0 or negative integer value indicates that the decimal point lies to the left of the first digit. The sign parameter points to an integer that indicates the sign of the converted number. If the integer value is 0, the number is positive. Otherwise, the number is negative.

_ecvt and _fcvt use a single statically allocated buffer for the conversion. Each call to one of these routines destroys the result of the previous call.

Example

/* ECVT.C: This program uses _ecvt to convert a
 * floating-point number to a character string.
 */

#include <stdlib.h>
#include <stdio.h>

void main( void )
{
   int     decimal,   sign;
   char    *buffer;
   int     precision = 10;
   double  source = 3.1415926535;

   buffer = _ecvt( source, precision, &decimal, &sign );
   printf( "source: %2.10f   buffer: '%s'  decimal: %d  sign: %d\n",
           source, buffer, decimal, sign );
}

Output

source: 3.1415926535   buffer: '3141592654'  decimal: 1   sign: 0

Data Conversion Routines |  Floating-Point Support Routines

See Also   atof, _fcvt, _gcvt