Header File 

stdlib.h  

Category 

Conversion Routines, Math Routines 

Prototype 

char *gcvt(double value, int ndec, char *buf); 

Description 

Converts floating-point number to a string. 

gcvt converts value to a null-terminated ASCII string and stores the string in buf. It produces ndec significant digits in FORTRAN F format, if possible; otherwise, it returns the value in the printf E format (ready for printing). It might suppress trailing zeros. 

Return Value 

gcvt returns the address of the string pointed to by buf. 

Example  

#include <stdlib.h>
#include <stdio.h>
int main(void)
{
   char str[25];
   double num;
   int sig = 5; /* significant digits */
   /* a regular number */
   num = 9.876;
   gcvt(num, sig, str);
   printf("string = %s\n", str);
   /* a negative number */
   num = -123.4567;
   gcvt(num, sig, str);
   printf("string = %s\n", str);
   /* scientific notation */
   num = 0.678e5;
   gcvt(num, sig, str);
   printf("string = %s\n", str);
   return(0);
}

Portability