ecvt,ecvtf,fcvt,fcvtf---double or float to string
#include <stdlib.h>
char *ecvt(double val, int chars, int *decpt, int *sgn);
char *ecvtf(float val, int chars, int *decpt, int *sgn);
char *fcvt(double val, int decimals,
int *decpt, int *sgn);
char *fcvtf(float val, int decimals,
int *decpt, int *sgn);
Descriptionecvt and fcvt produce (null-terminated) strings of digits
representating the double number val.
ecvtf and fcvtf produce the corresponding character
representations of float numbers.
(The stdlib functions ecvtbuf and fcvtbuf are reentrant
versions of ecvt and fcvt.)
The only difference between ecvt and fcvt is the
interpretation of the second argument (chars or decimals).
For ecvt, the second argument chars specifies the total number
of characters to write (which is also the number of significant digits
in the formatted string, since these two functions write only digits).
For fcvt, the second argument decimals specifies the number of
characters to write after the decimal point; all digits for the integer
part of val are always included.
Since ecvt and fcvt write only digits in the output string,
they record the location of the decimal point in *decpt, and
the sign of the number in *sgn. After formatting a number,
*decpt contains the number of digits to the left of the
decimal point. *sgn contains 0 if the number is positive,
and 1 if it is negative.
Returns
All four functions return a pointer to the new string containing a
character representation of val.
Portability
None of these functions are ANSI C.
Supporting OS subroutines required: close, fstat, isatty,
lseek, read, sbrk, write.