linux man page for fcvt

ECVT(3) 						     Linux Programmer's Manual							   ECVT(3)

NAME
       ecvt, fcvt - convert a floating-point number to a string

SYNOPSIS
       #include <stdlib.h>

       char *ecvt(double number, int ndigits, int *decpt, int *sign);

       char *fcvt(double number, int ndigits, int *decpt, int *sign);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       ecvt(), fcvt():
	   Since glibc 2.12:
	       _SVID_SOURCE ||
		   (_XOPEN_SOURCE >= 500 ||
		       _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) &&
		   !(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600)
	   Before glibc 2.12:
	       _SVID_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED

DESCRIPTION
       The  ecvt()  function  converts	number	to a null-terminated string of ndigits digits (where ndigits is reduced to a system-specific limit
       determined by the precision of a double), and returns a pointer to the string.  The high-order digit is nonzero,  unless  number  is  zero.
       The low order digit is rounded.	The string itself does not contain a decimal point; however, the position of the decimal point relative to
       the start of the string is stored in *decpt.  A negative value for *decpt means that the decimal point is to the left of the start  of  the
       string.	 If  the sign of number is negative, *sign is set to a nonzero value, otherwise it is set to 0.  If number is zero, it is unspeci-
       fied whether *decpt is 0 or 1.

       The fcvt() function is identical to ecvt(), except that ndigits specifies the number of digits after the decimal point.

RETURN VALUE
       Both the ecvt() and fcvt() functions return a pointer to a static string containing the ASCII representation of number.	The static  string
       is overwritten by each call to ecvt() or fcvt().

CONFORMING TO
       SVr2;  marked  as LEGACY in POSIX.1-2001.  POSIX.1-2008 removes the specifications of ecvt() and fcvt(), recommending the use of sprintf(3)
       instead (though snprintf(3) may be preferable).

NOTES
       Linux libc4 and libc5 specified the type of ndigits as size_t.  Not all locales use a point as the radix character ("decimal point").

SEE ALSO
       ecvt_r(3), gcvt(3), qecvt(3), setlocale(3), sprintf(3)

COLOPHON
       This page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

								    2010-09-20								   ECVT(3)